Commit Graph

481 Commits

Author SHA1 Message Date
Linus Torvalds
48b5259cf0 Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
 "A single commit micro-optimizing short user copies on certain Intel
  CPUs"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/uaccess: Optimize copy_user_enhanced_fast_string() for short strings
2017-07-03 13:38:28 -07:00
Linus Torvalds
7447d56217 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "Most of the changes are for tooling, the main changes in this cycle were:

   - Improve Intel-PT hardware tracing support, both on the kernel and
     on the tooling side: PTWRITE instruction support, power events for
     C-state tracing, etc. (Adrian Hunter)

   - Add support to measure SMI cost to the x86 architecture, with
     tooling support in 'perf stat' (Kan Liang)

   - Support function filtering in 'perf ftrace', plus related
     improvements (Namhyung Kim)

   - Allow adding and removing fields to the default 'perf script'
     columns, using + or - as field prefixes to do so (Andi Kleen)

   - Allow resolving the DSO name with 'perf script -F brstack{sym,off},dso'
     (Mark Santaniello)

   - Add perf tooling unwind support for PowerPC (Paolo Bonzini)

   - ... and various other improvements as well"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits)
  perf auxtrace: Add CPU filter support
  perf intel-pt: Do not use TSC packets for calculating CPU cycles to TSC
  perf intel-pt: Update documentation to include new ptwrite and power events
  perf intel-pt: Add example script for power events and PTWRITE
  perf intel-pt: Synthesize new power and "ptwrite" events
  perf intel-pt: Move code in intel_pt_synth_events() to simplify attr setting
  perf intel-pt: Factor out intel_pt_set_event_name()
  perf intel-pt: Tidy messages into called function intel_pt_synth_event()
  perf intel-pt: Tidy Intel PT evsel lookup into separate function
  perf intel-pt: Join needlessly wrapped lines
  perf intel-pt: Remove unused instructions_sample_period
  perf intel-pt: Factor out common code synthesizing event samples
  perf script: Add synthesized Intel PT power and ptwrite events
  perf/x86/intel: Constify the 'lbr_desc[]' array and make a function static
  perf script: Add 'synth' field for synthesized event payloads
  perf auxtrace: Add itrace option to output power events
  perf auxtrace: Add itrace option to output ptwrite events
  tools include: Add byte-swapping macros to kernel.h
  perf script: Add 'synth' event type for synthesized events
  x86/insn: perf tools: Add new ptwrite instruction
  ...
2017-07-03 12:40:46 -07:00
Josh Poimboeuf
c207aee480 objtool, x86: Add several functions and files to the objtool whitelist
In preparation for an objtool rewrite which will have broader checks,
whitelist functions and files which cause problems because they do
unusual things with the stack.

These whitelists serve as a TODO list for which functions and files
don't yet have undwarf unwinder coverage.  Eventually most of the
whitelists can be removed in favor of manual CFI hint annotations or
objtool improvements.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/7f934a5d707a574bda33ea282e9478e627fb1829.1498659915.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-30 10:19:19 +02:00
Paolo Abeni
236222d393 x86/uaccess: Optimize copy_user_enhanced_fast_string() for short strings
According to the Intel datasheet, the REP MOVSB instruction
exposes a pretty heavy setup cost (50 ticks), which hurts
short string copy operations.

This change tries to avoid this cost by calling the explicit
loop available in the unrolled code for strings shorter
than 64 bytes.

The 64 bytes cutoff value is arbitrary from the code logic
point of view - it has been selected based on measurements,
as the largest value that still ensures a measurable gain.

Micro benchmarks of the __copy_from_user() function with
lengths in the [0-63] range show this performance gain
(shorter the string, larger the gain):

 - in the [55%-4%] range on Intel Xeon(R) CPU E5-2690 v4
 - in the [72%-9%] range on Intel Core i7-4810MQ

Other tested CPUs - namely Intel Atom S1260 and AMD Opteron
8216 - show no difference, because they do not expose the
ERMS feature bit.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/4533a1d101fd460f80e21329a34928fad521c1d4.1498744345.git.pabeni@redhat.com
[ Clarified the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-30 09:52:51 +02:00
Adrian Hunter
d5b1a5f660 x86/insn: perf tools: Add new ptwrite instruction
Add ptwrite to the op code map and the perf tools new instructions test.
To run the test:

  $ tools/perf/perf test "x86 ins"
  39: Test x86 instruction decoder - new instructions          : Ok

Or to see the details:

  $ tools/perf/perf test -v "x86 ins" 2>&1 | grep ptwrite

For information about ptwrite, refer the Intel SDM.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/1495180230-19367-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-27 11:58:04 -03:00
Dan Williams
4e4f00a9b5 x86, dax, libnvdimm: remove wb_cache_pmem() indirection
With all handling of the CONFIG_ARCH_HAS_PMEM_API case being moved to
libnvdimm and the pmem driver directly we do not need to provide global
wrappers and fallbacks in the CONFIG_ARCH_HAS_PMEM_API=n case. The pmem
driver will simply not link to arch_wb_cache_pmem() in that case.  Same
as before, pmem flushing is only defined for x86_64, via
clean_cache_range(), but it is straightforward to add other archs in the
future.

arch_wb_cache_pmem() is an exported function since the pmem module needs
to find it, but it is privately declared in drivers/nvdimm/pmem.h because
there are no consumers outside of the pmem driver.

Cc: <x86@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-15 14:35:24 -07:00
Dan Williams
0aed55af88 x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations
The pmem driver has a need to transfer data with a persistent memory
destination and be able to rely on the fact that the destination writes are not
cached. It is sufficient for the writes to be flushed to a cpu-store-buffer
(non-temporal / "movnt" in x86 terms), as we expect userspace to call fsync()
to ensure data-writes have reached a power-fail-safe zone in the platform. The
fsync() triggers a REQ_FUA or REQ_FLUSH to the pmem driver which will turn
around and fence previous writes with an "sfence".

Implement a __copy_from_user_inatomic_flushcache, memcpy_page_flushcache, and
memcpy_flushcache, that guarantee that the destination buffer is not dirty in
the cpu cache on completion. The new copy_from_iter_flushcache and sub-routines
will be used to replace the "pmem api" (include/linux/pmem.h +
arch/x86/include/asm/pmem.h). The availability of copy_from_iter_flushcache()
and memcpy_flushcache() are gated by the CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
config symbol, and fallback to copy_from_iter_nocache() and plain memcpy()
otherwise.

This is meant to satisfy the concern from Linus that if a driver wants to do
something beyond the normal nocache semantics it should be something private to
that driver [1], and Al's concern that anything uaccess related belongs with
the rest of the uaccess code [2].

The first consumer of this interface is a new 'copy_from_iter' dax operation so
that pmem can inject cache maintenance operations without imposing this
overhead on other dax-capable drivers.

[1]: https://lists.01.org/pipermail/linux-nvdimm/2017-January/008364.html
[2]: https://lists.01.org/pipermail/linux-nvdimm/2017-April/009942.html

Cc: <x86@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-09 09:09:56 -07:00
Matthias Kaehlcke
121843eb02 x86/mm/kaslr: Use the _ASM_MUL macro for multiplication to work around Clang incompatibility
The constraint "rm" allows the compiler to put mix_const into memory.
When the input operand is a memory location then MUL needs an operand
size suffix, since Clang can't infer the multiplication width from the
operand.

Add and use the _ASM_MUL macro which determines the operand size and
resolves to the NUL instruction with the corresponding suffix.

This fixes the following error when building with clang:

  CC      arch/x86/lib/kaslr.o
  /tmp/kaslr-dfe1ad.s: Assembler messages:
  /tmp/kaslr-dfe1ad.s:182: Error: no instruction mnemonic suffix given and no register operands; can't size instruction

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Cc: Grant Grundler <grundler@chromium.org>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Davidson <md@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170501224741.133938-1-mka@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-05 08:31:05 +02:00
Ingo Molnar
415812f2d6 Merge branch 'linus' into x86/urgent, to pick up dependent commits
We are going to fix a bug introduced by a more recent commit, so
refresh the tree.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-05 08:21:03 +02:00
Josh Poimboeuf
42fc6c6cb1 x86/asm: Don't use RBP as a temporary register in csum_partial_copy_generic()
Andrey Konovalov reported the following warning while fuzzing the kernel
with syzkaller:

  WARNING: kernel stack regs at ffff8800686869f8 in a.out:4933 has bad 'bp' value c3fc855a10167ec0

The unwinder dump revealed that RBP had a bad value when an interrupt
occurred in csum_partial_copy_generic().

That function saves RBP on the stack and then overwrites it, using it as
a scratch register.  That's problematic because it breaks stack traces
if an interrupt occurs in the middle of the function.

Replace the usage of RBP with another callee-saved register (R15) so
stack traces are no longer affected.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: linux-sctp@vger.kernel.org
Cc: netdev <netdev@vger.kernel.org>
Cc: syzkaller <syzkaller@googlegroups.com>
Link: http://lkml.kernel.org/r/4b03a961efda5ec9bfe46b7b9c9ad72d1efad343.1493909486.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-05 07:59:24 +02:00
Linus Torvalds
3fb9268e43 Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
 "The main changes in this cycle were:

   - unwinder fixes and enhancements

   - improve ftrace interaction with the unwinder

   - optimize the code footprint of WARN() and related debugging
     constructs

   - ... plus misc updates, cleanups and fixes"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  x86/unwind: Dump all stacks in unwind_dump()
  x86/unwind: Silence more entry-code related warnings
  x86/ftrace: Fix ebp in ftrace_regs_caller that screws up unwinder
  x86/unwind: Remove unused 'sp' parameter in unwind_dump()
  x86/unwind: Prepend hex mask value with '0x' in unwind_dump()
  x86/unwind: Properly zero-pad 32-bit values in unwind_dump()
  x86/unwind: Ensure stack pointer is aligned
  debug: Avoid setting BUGFLAG_WARNING twice
  x86/unwind: Silence entry-related warnings
  x86/unwind: Read stack return address in update_stack_state()
  x86/unwind: Move common code into update_stack_state()
  debug: Fix __bug_table[] in arch linker scripts
  debug: Add _ONCE() logic to report_bug()
  x86/debug: Define BUG() again for !CONFIG_BUG
  x86/debug: Implement __WARN() using UD0
  x86/ftrace: Use Makefile logic instead of #ifdef for compiling ftrace_*.o
  x86/ftrace: Add -mfentry support to x86_32 with DYNAMIC_FTRACE set
  x86/ftrace: Clean up ftrace_regs_caller
  x86/ftrace: Add stack frame pointer to ftrace_caller
  x86/ftrace: Move the ftrace specific code out of entry_32.S
  ...
2017-05-01 22:07:51 -07:00
Linus Torvalds
16b76293c5 Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Ingo Molnar:
 "The biggest changes in this cycle were:

   - reworking of the e820 code: separate in-kernel and boot-ABI data
     structures and apply a whole range of cleanups to the kernel side.

     No change in functionality.

   - enable KASLR by default: it's used by all major distros and it's
     out of the experimental stage as well.

   - ... misc fixes and cleanups"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
  x86/KASLR: Fix kexec kernel boot crash when KASLR randomization fails
  x86/reboot: Turn off KVM when halting a CPU
  x86/boot: Fix BSS corruption/overwrite bug in early x86 kernel startup
  x86: Enable KASLR by default
  boot/param: Move next_arg() function to lib/cmdline.c for later reuse
  x86/boot: Fix Sparse warning by including required header file
  x86/boot/64: Rename start_cpu()
  x86/xen: Update e820 table handling to the new core x86 E820 code
  x86/boot: Fix pr_debug() API braindamage
  xen, x86/headers: Add <linux/device.h> dependency to <asm/xen/page.h>
  x86/boot/e820: Simplify e820__update_table()
  x86/boot/e820: Separate the E820 ABI structures from the in-kernel structures
  x86/boot/e820: Fix and clean up e820_type switch() statements
  x86/boot/e820: Rename the remaining E820 APIs to the e820__*() prefix
  x86/boot/e820: Remove unnecessary #include's
  x86/boot/e820: Rename e820_mark_nosave_regions() to e820__register_nosave_regions()
  x86/boot/e820: Rename e820_reserve_resources*() to e820__reserve_resources*()
  x86/boot/e820: Use bool in query APIs
  x86/boot/e820: Document e820__reserve_setup_data()
  x86/boot/e820: Clean up __e820__update_table() et al
  ...
2017-05-01 20:51:12 -07:00
Linus Torvalds
5db6db0d40 Merge branch 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull uaccess unification updates from Al Viro:
 "This is the uaccess unification pile. It's _not_ the end of uaccess
  work, but the next batch of that will go into the next cycle. This one
  mostly takes copy_from_user() and friends out of arch/* and gets the
  zero-padding behaviour in sync for all architectures.

  Dealing with the nocache/writethrough mess is for the next cycle;
  fortunately, that's x86-only. Same for cleanups in iov_iter.c (I am
  sold on access_ok() in there, BTW; just not in this pile), same for
  reducing __copy_... callsites, strn*... stuff, etc. - there will be a
  pile about as large as this one in the next merge window.

  This one sat in -next for weeks. -3KLoC"

* 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (96 commits)
  HAVE_ARCH_HARDENED_USERCOPY is unconditional now
  CONFIG_ARCH_HAS_RAW_COPY_USER is unconditional now
  m32r: switch to RAW_COPY_USER
  hexagon: switch to RAW_COPY_USER
  microblaze: switch to RAW_COPY_USER
  get rid of padding, switch to RAW_COPY_USER
  ia64: get rid of copy_in_user()
  ia64: sanitize __access_ok()
  ia64: get rid of 'segment' argument of __do_{get,put}_user()
  ia64: get rid of 'segment' argument of __{get,put}_user_check()
  ia64: add extable.h
  powerpc: get rid of zeroing, switch to RAW_COPY_USER
  esas2r: don't open-code memdup_user()
  alpha: fix stack smashing in old_adjtimex(2)
  don't open-code kernel_setsockopt()
  mips: switch to RAW_COPY_USER
  mips: get rid of tail-zeroing in primitives
  mips: make copy_from_user() zero tail explicitly
  mips: clean and reorder the forest of macros...
  mips: consolidate __invoke_... wrappers
  ...
2017-05-01 14:41:04 -07:00
Janakarajan Natarajan
88d879d29f Prevent timer value 0 for MWAITX
Newer hardware has uncovered a bug in the software implementation of
using MWAITX for the delay function. A value of 0 for the timer is meant
to indicate that a timeout will not be used to exit MWAITX. On newer
hardware this can result in MWAITX never returning, resulting in NMI
soft lockup messages being printed. On older hardware, some of the other
conditions under which MWAITX can exit masked this issue. The AMD APM
does not currently document this and will be updated.

Please refer to http://marc.info/?l=kvm&m=148950623231140 for
information regarding NMI soft lockup messages on an AMD Ryzen 1800X.
This has been root-caused as a 0 passed to MWAITX causing it to wait
indefinitely.

This change has the added benefit of avoiding the unnecessary setup of
MONITORX/MWAITX when the delay value is zero.

Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Link: http://lkml.kernel.org/r/1493156643-29366-1-git-send-email-Janakarajan.Natarajan@amd.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-04-30 13:35:11 +02:00
Al Viro
beba3a20bf x86: switch to RAW_COPY_USER
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-29 12:06:28 -04:00
Al Viro
a41e0d7542 x86: don't wank with magical size in __copy_in_user()
... especially since copy_in_user() doesn't

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-29 12:04:35 -04:00
Al Viro
3f763453e6 kill __copy_from_user_nocache()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28 18:24:05 -04:00
Al Viro
122b05ddf5 amd64: get rid of zeroing
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28 18:24:04 -04:00
Tony Luck
26a37ab319 x86/mce: Fix copy/paste error in exception table entries
Back in commit:

  92b0729c34 ("x86/mm, x86/mce: Add memcpy_mcsafe()")

... I made a copy/paste error setting up the exception table entries
and ended up with two for label .L_cache_w3 and none for .L_cache_w2.

This means that if we take a machine check on:

  .L_cache_w2: movq 2*8(%rsi), %r10

then we don't have an exception table entry for this instruction
and we can't recover.

Fix: s/3/2/

Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 92b0729c34 ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Link: http://lkml.kernel.org/r/1490046030-25862-1-git-send-email-tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-22 08:43:25 +01:00
Borislav Petkov
f25d384755 x86/asm: Optimize clear_page()
Currently, we CALL clear_page() which then JMPs to the proper function
chosen by the alternatives.

What we should do instead is CALL the proper function directly. (This
was something Ingo suggested a while ago). So let's do that.

Measuring our favourite kernel build workload shows that there are no
significant changes in performance.

AMD
===
  -- /tmp/before 2017-02-09 18:01:46.451961188 +0100
  ++ /tmp/after  2017-02-09 18:01:54.883961175 +0100
  @@ -1,15 +1,15 @@
    Performance counter stats for 'system wide' (5 runs):

  -    1028960.373643      cpu-clock (msec)          #    6.000 CPUs utilized            ( +-  1.41% )
  +    1023086.018961      cpu-clock (msec)          #    6.000 CPUs utilized            ( +-  1.20% )
  -           518,744      context-switches          #    0.504 K/sec                    ( +-  1.04% )
  +           518,254      context-switches          #    0.507 K/sec                    ( +-  1.01% )
  -            38,112      cpu-migrations            #    0.037 K/sec                    ( +-  1.95% )
  +            37,917      cpu-migrations            #    0.037 K/sec                    ( +-  1.02% )
  -        20,874,266      page-faults               #    0.020 M/sec                    ( +-  0.07% )
  +        20,918,897      page-faults               #    0.020 M/sec                    ( +-  0.18% )
  - 2,043,646,230,667      cycles                    #    1.986 GHz                      ( +-  0.14% )  (66.67%)
  + 2,045,305,584,032      cycles                    #    1.999 GHz                      ( +-  0.16% )  (66.67%)
  -   553,698,855,431      stalled-cycles-frontend   #   27.09% frontend cycles idle     ( +-  0.07% )  (66.67%)
  +   555,099,401,413      stalled-cycles-frontend   #   27.14% frontend cycles idle     ( +-  0.13% )  (66.67%)
  -   621,544,286,390      stalled-cycles-backend    #   30.41% backend cycles idle      ( +-  0.39% )  (66.67%)
  +   621,371,430,254      stalled-cycles-backend    #   30.38% backend cycles idle      ( +-  0.32% )  (66.67%)
  - 1,738,364,431,659      instructions              #    0.85  insn per cycle
  + 1,739,895,771,901      instructions              #    0.85  insn per cycle
  -                                                  #    0.36  stalled cycles per insn  ( +-  0.11% )  (66.67%)
  +                                                  #    0.36  stalled cycles per insn  ( +-  0.13% )  (66.67%)
  -   391,170,943,850      branches                  #  380.161 M/sec                    ( +-  0.13% )  (66.67%)
  +   391,398,551,757      branches                  #  382.567 M/sec                    ( +-  0.13% )  (66.67%)
  -    22,567,810,411      branch-misses             #    5.77% of all branches          ( +-  0.11% )  (66.67%)
  +    22,574,726,683      branch-misses             #    5.77% of all branches          ( +-  0.13% )  (66.67%)

  -     171.480741921 seconds time elapsed                                          ( +-  1.41% )
  +     170.509229451 seconds time elapsed                                          ( +-  1.20% )

Intel
=====

  -- /tmp/before 2017-02-09 20:36:19.851947473 +0100
  ++ /tmp/after  2017-02-09 20:36:30.151947458 +0100
  @@ -1,15 +1,15 @@
    Performance counter stats for 'system wide' (5 runs):

  -    2207248.598126      cpu-clock (msec)          #    8.000 CPUs utilized            ( +-  0.69% )
  +    2213300.106631      cpu-clock (msec)          #    8.000 CPUs utilized            ( +-  0.73% )
  -           899,342      context-switches          #    0.407 K/sec                    ( +-  0.68% )
  +           898,381      context-switches          #    0.406 K/sec                    ( +-  0.79% )
  -            80,553      cpu-migrations            #    0.036 K/sec                    ( +-  1.13% )
  +            80,979      cpu-migrations            #    0.037 K/sec                    ( +-  1.11% )
  -        36,171,148      page-faults               #    0.016 M/sec                    ( +-  0.02% )
  +        36,179,791      page-faults               #    0.016 M/sec                    ( +-  0.02% )
  - 6,665,288,826,484      cycles                    #    3.020 GHz                      ( +-  0.07% )  (83.33%)
  + 6,671,638,410,799      cycles                    #    3.014 GHz                      ( +-  0.06% )  (83.33%)
  - 5,065,975,115,197      stalled-cycles-frontend   #   76.01% frontend cycles idle     ( +-  0.11% )  (83.33%)
  + 5,076,835,183,223      stalled-cycles-frontend   #   76.10% frontend cycles idle     ( +-  0.11% )  (83.33%)
  - 3,841,556,350,614      stalled-cycles-backend    #   57.64% backend cycles idle      ( +-  0.13% )  (66.67%)
  + 3,852,823,974,333      stalled-cycles-backend    #   57.75% backend cycles idle      ( +-  0.12% )  (66.67%)
  - 4,148,398,171,079      instructions              #    0.62  insn per cycle
  + 4,148,997,156,059      instructions              #    0.62  insn per cycle
  -                                                  #    1.22  stalled cycles per insn  ( +-  0.10% )  (83.33%)
  +                                                  #    1.22  stalled cycles per insn  ( +-  0.11% )  (83.33%)
  -   887,187,118,591      branches                  #  401.943 M/sec                    ( +-  0.09% )  (83.33%)
  +   887,271,341,121      branches                  #  400.882 M/sec                    ( +-  0.11% )  (83.33%)
  -    30,139,439,034      branch-misses             #    3.40% of all branches          ( +-  0.09% )  (83.33%)
  +    30,134,864,997      branch-misses             #    3.40% of all branches          ( +-  0.06% )  (83.33%)

  -     275.904405540 seconds time elapsed                                          ( +-  0.69% )
  +     276.660352016 seconds time elapsed                                          ( +-  0.73% )

allmodconfig vmlinux size grows by a ~1Kb but that's fine - we optimize
our calling of the clear_page variants.

     text    data     bss     dec     hex filename
  9051979 23067670        27009024        59128673        3863b61		vmlinux
  9053000 23067670        27009024        59129694        3863f5e		vmlinux.clear_page

Reported-by: kernel test robot <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170215111927.emdgxf2pide3kwro@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-07 08:28:00 +01:00
Ingo Molnar
0871d5a66d Merge branch 'linus' into WIP.x86/boot, to fix up conflicts and to pick up updates
Conflicts:
	arch/x86/xen/setup.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-01 09:02:26 +01:00
Ingo Molnar
66441bd3cf x86/boot/e820: Move asm/e820.h to asm/e820/api.h
In line with asm/e820/types.h, move the e820 API declarations to
asm/e820/api.h and update all usage sites.

This is just a mechanical, obviously correct move & replace patch,
there will be subsequent changes to clean up the code and to make
better use of the new header organization.

Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28 09:31:13 +01:00
Jiri Slaby
4c45c5167c x86/timer: Make delay() work during early bootup
When a panic happens during bootup, "Rebooting in X seconds.." is
shown, but reboot happens immediatelly. It is because panic() uses mdelay()
and mdelay() calls __const_udelay() immediately, which does not
work while booting.

The per_cpu cpu_info.loops_per_jiffy value is not initialized yet, so
__const_udelay() actually multiplies the number of loops by zero. This
results in __const_udelay() to delay the execution only by a nanosecond
or so.

So check whether cpu_info.loops_per_jiffy is zero and use
loops_per_jiffy in that case. mdelay() will not be so precise without
proper calibration, but it works relatively well.

Before:

  [    0.170039] delaying 100ms
  [    0.170828] done

After

  [    0.214042] delaying 100ms
  [    0.313974] done

I do not think the added check matters given we are about to spin the
processor in the next few hundred cycles.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170119114730.2670-1-jslaby@suse.cz
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-22 10:03:12 +01:00
Linus Torvalds
7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
Linus Torvalds
5645688f9d Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
 "The main changes in this development cycle were:

   - a large number of call stack dumping/printing improvements: higher
     robustness, better cross-context dumping, improved output, etc.
     (Josh Poimboeuf)

   - vDSO getcpu() performance improvement for future Intel CPUs with
     the RDPID instruction (Andy Lutomirski)

   - add two new Intel AVX512 features and the CPUID support
     infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela,
     He Chen)

   - more copy-user unification (Borislav Petkov)

   - entry code assembly macro simplifications (Alexander Kuleshov)

   - vDSO C/R support improvements (Dmitry Safonov)

   - misc fixes and cleanups (Borislav Petkov, Paul Bolle)"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  scripts/decode_stacktrace.sh: Fix address line detection on x86
  x86/boot/64: Use defines for page size
  x86/dumpstack: Make stack name tags more comprehensible
  selftests/x86: Add test_vdso to test getcpu()
  x86/vdso: Use RDPID in preference to LSL when available
  x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl()
  x86/cpufeatures: Enable new AVX512 cpu features
  x86/cpuid: Provide get_scattered_cpuid_leaf()
  x86/cpuid: Cleanup cpuid_regs definitions
  x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants
  x86/unwind: Ensure stack grows down
  x86/vdso: Set vDSO pointer only after success
  x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE
  x86/unwind: Detect bad stack return address
  x86/dumpstack: Warn on stack recursion
  x86/unwind: Warn on bad frame pointer
  x86/decoder: Use stderr if insn sanity test fails
  x86/decoder: Use stdout if insn decoder test is successful
  mm/page_alloc: Remove kernel address exposure in free_reserved_area()
  x86/dumpstack: Remove raw stack dump
  ...
2016-12-12 13:49:57 -08:00
Borislav Petkov
5d07c2cc19 x86/msr: Cleanup/streamline MSR helpers
Make the MSR argument an unsigned int, both low and high u32, put
"notrace" last in the function signature. Reflow function signatures for
better readability and cleanup white space.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-16 10:23:02 +01:00
Borislav Petkov
adb402cd14 x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants
We already have the same functionality in usercopy_32.c. Share it with
64-bit and get rid of some more asm glue which is not needed anymore.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161031151015.22087-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-01 07:41:27 +01:00
Linus Torvalds
84d69848c9 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek:

 - EXPORT_SYMBOL for asm source by Al Viro.

   This does bring a regression, because genksyms no longer generates
   checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
   working on a patch to fix this.

   Plus, we are talking about functions like strcpy(), which rarely
   change prototypes.

 - Fixes for PPC fallout of the above by Stephen Rothwell and Nick
   Piggin

 - fixdep speedup by Alexey Dobriyan.

 - preparatory work by Nick Piggin to allow architectures to build with
   -ffunction-sections, -fdata-sections and --gc-sections

 - CONFIG_THIN_ARCHIVES support by Stephen Rothwell

 - fix for filenames with colons in the initramfs source by me.

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
  initramfs: Escape colons in depfile
  ppc: there is no clear_pages to export
  powerpc/64: whitelist unresolved modversions CRCs
  kbuild: -ffunction-sections fix for archs with conflicting sections
  kbuild: add arch specific post-link Makefile
  kbuild: allow archs to select link dead code/data elimination
  kbuild: allow architectures to use thin archives instead of ld -r
  kbuild: Regenerate genksyms lexer
  kbuild: genksyms fix for typeof handling
  fixdep: faster CONFIG_ search
  ia64: move exports to definitions
  sparc32: debride memcpy.S a bit
  [sparc] unify 32bit and 64bit string.h
  sparc: move exports to definitions
  ppc: move exports to definitions
  arm: move exports to definitions
  s390: move exports to definitions
  m68k: move exports to definitions
  alpha: move exports to actual definitions
  x86: move exports to actual definitions
  ...
2016-10-14 14:26:58 -07:00
Tony Luck
9a6fb28a35 x86/mce: Improve memcpy_mcsafe()
Use the mcsafe_key defined in the previous patch to make decisions on which
copy function to use. We can't use the FEATURE bit any more because PCI
quirks run too late to affect the patching of code. So we use a static key.

Turn memcpy_mcsafe() into an inline function to make life easier for
callers. The assembly code that actually does the copy is now named
memcpy_mcsafe_unrolled()

Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Boris Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/bfde2fc774e94f53d91b70a4321c85a0d33e7118.1472754712.git.tony.luck@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-05 11:47:31 +02:00
Nicolas Iooss
62d16b5a3f x86/mm/kaslr: Fix -Wformat-security warning
debug_putstr() is used to output strings without using printf-like
formatting but debug_putstr(v) is defined as early_printk(v) in
arch/x86/lib/kaslr.c.

This makes clang reports the following warning when building
with -Wformat-security:

    arch/x86/lib/kaslr.c:57:15: warning: format string is not a string
    literal (potentially insecure) [-Wformat-security]
            debug_putstr(purpose);
                         ^~~~~~~

Fix this by using "%s" in early_printk().

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160806102039.27221-1-nicolas.iooss_linux@m4x.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-11 10:58:12 +02:00
Ville Syrjälä
65ea11ec6a x86/hweight: Don't clobber %rdi
The caller expects %rdi to remain intact, push+pop it make that happen.

Fixes the following kind of explosions on my core2duo machine when
trying to reboot or shut down:

  general protection fault: 0000 [] PREEMPT SMP
  Modules linked in: i915 i2c_algo_bit drm_kms_helper cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea drm netconsole configfs binfmt_misc iTCO_wdt psmouse pcspkr snd_hda_codec_idt e100 coretemp hwmon snd_hda_codec_generic i2c_i801 mii i2c_smbus lpc_ich mfd_core snd_hda_intel uhci_hcd snd_hda_codec snd_hwdep snd_hda_core ehci_pci 8250 ehci_hcd snd_pcm 8250_base usbcore evdev serial_core usb_common parport_pc parport snd_timer snd soundcore
  CPU: 0 PID: 3070 Comm: reboot Not tainted 4.8.0-rc1-perf-dirty 
  Hardware name:                  /D946GZIS, BIOS TS94610J.86A.0087.2007.1107.1049 11/07/2007
  task: ffff88012a0b4080 task.stack: ffff880123850000
  RIP: 0010:[<ffffffff81003c92>]  [<ffffffff81003c92>] x86_perf_event_update+0x52/0xc0
  RSP: 0018:ffff880123853b60  EFLAGS: 00010087
  RAX: 0000000000000001 RBX: ffff88012fc0a3c0 RCX: 000000000000001e
  RDX: 0000000000000000 RSI: 0000000040000000 RDI: ffff88012b014800
  RBP: ffff880123853b88 R08: ffffffffffffffff R09: 0000000000000000
  R10: ffffea0004a012c0 R11: ffffea0004acedc0 R12: ffffffff80000001
  R13: ffff88012b0149c0 R14: ffff88012b014800 R15: 0000000000000018
  FS:  00007f8b155cd700(0000) GS:ffff88012fc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f8b155f5000 CR3: 000000012a2d7000 CR4: 00000000000006f0
  Stack:
   ffff88012fc0a3c0 ffff88012b014800 0000000000000004 0000000000000001
   ffff88012fc1b750 ffff880123853bb0 ffffffff81003d59 ffff88012b014800
   ffff88012fc0a3c0 ffff88012b014800 ffff880123853bd8 ffffffff81003e13
  Call Trace:
   [<ffffffff81003d59>] x86_pmu_stop+0x59/0xd0
   [<ffffffff81003e13>] x86_pmu_del+0x43/0x140
   [<ffffffff8111705d>] event_sched_out.isra.105+0xbd/0x260
   [<ffffffff8111738d>] __perf_remove_from_context+0x2d/0xb0
   [<ffffffff8111745d>] __perf_event_exit_context+0x4d/0x70
   [<ffffffff810c8826>] generic_exec_single+0xb6/0x140
   [<ffffffff81117410>] ? __perf_remove_from_context+0xb0/0xb0
   [<ffffffff81117410>] ? __perf_remove_from_context+0xb0/0xb0
   [<ffffffff810c898f>] smp_call_function_single+0xdf/0x140
   [<ffffffff81113d27>] perf_event_exit_cpu_context+0x87/0xc0
   [<ffffffff81113d73>] perf_reboot+0x13/0x40
   [<ffffffff8107578a>] notifier_call_chain+0x4a/0x70
   [<ffffffff81075ad7>] __blocking_notifier_call_chain+0x47/0x60
   [<ffffffff81075b06>] blocking_notifier_call_chain+0x16/0x20
   [<ffffffff81076a1d>] kernel_restart_prepare+0x1d/0x40
   [<ffffffff81076ae2>] kernel_restart+0x12/0x60
   [<ffffffff81076d56>] SYSC_reboot+0xf6/0x1b0
   [<ffffffff811a823c>] ? mntput_no_expire+0x2c/0x1b0
   [<ffffffff811a83e4>] ? mntput+0x24/0x40
   [<ffffffff811894fc>] ? __fput+0x16c/0x1e0
   [<ffffffff811895ae>] ? ____fput+0xe/0x10
   [<ffffffff81072fc3>] ? task_work_run+0x83/0xa0
   [<ffffffff81001623>] ? exit_to_usermode_loop+0x53/0xc0
   [<ffffffff8100105a>] ? trace_hardirqs_on_thunk+0x1a/0x1c
   [<ffffffff81076e6e>] SyS_reboot+0xe/0x10
   [<ffffffff814c4ba5>] entry_SYSCALL_64_fastpath+0x18/0xa3
  Code: 7c 4c 8d af c0 01 00 00 49 89 fe eb 10 48 09 c2 4c 89 e0 49 0f b1 55 00 4c 39 e0 74 35 4d 8b a6 c0 01 00 00 41 8b 8e 60 01 00 00 <0f> 33 8b 35 6e 02 8c 00 48 c1 e2 20 85 f6 7e d2 48 89 d3 89 cf
  RIP  [<ffffffff81003c92>] x86_perf_event_update+0x52/0xc0
   RSP <ffff880123853b60>
  ---[ end trace 7ec95181faf211be ]---
  note: reboot[3070] exited with preempt_count 2

Cc: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Fixes: f5967101e9 ("x86/hweight: Get rid of the special calling convention")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-08 10:58:25 -07:00
Al Viro
784d5699ed x86: move exports to actual definitions
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-07 23:47:15 -04:00
Linus Torvalds
aeb35d6b74 Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 header cleanups from Ingo Molnar:
 "This tree is a cleanup of the x86 tree reducing spurious uses of
  module.h - which should improve build performance a bit"

* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, crypto: Restore MODULE_LICENSE() to glue_helper.c so it loads
  x86/apic: Remove duplicated include from probe_64.c
  x86/ce4100: Remove duplicated include from ce4100.c
  x86/headers: Include spinlock_types.h in x8664_ksyms_64.c for missing spinlock_t
  x86/platform: Delete extraneous MODULE_* tags fromm ts5500
  x86: Audit and remove any remaining unnecessary uses of module.h
  x86/kvm: Audit and remove any unnecessary uses of module.h
  x86/xen: Audit and remove any unnecessary uses of module.h
  x86/platform: Audit and remove any unnecessary uses of module.h
  x86/lib: Audit and remove any unnecessary uses of module.h
  x86/kernel: Audit and remove any unnecessary uses of module.h
  x86/mm: Audit and remove any unnecessary uses of module.h
  x86: Don't use module.h just for AUTHOR / LICENSE tags
2016-08-01 14:23:42 -04:00
Linus Torvalds
f0c98ebc57 libnvdimm for 4.8
1/ Replace pcommit with ADR / directed-flushing:
    The pcommit instruction, which has not shipped on any product, is
    deprecated. Instead, the requirement is that platforms implement either
    ADR, or provide one or more flush addresses per nvdimm. ADR
    (Asynchronous DRAM Refresh) flushes data in posted write buffers to the
    memory controller on a power-fail event. Flush addresses are defined in
    ACPI 6.x as an NVDIMM Firmware Interface Table (NFIT) sub-structure:
    "Flush Hint Address Structure". A flush hint is an mmio address that
    when written and fenced assures that all previous posted writes
    targeting a given dimm have been flushed to media.
 
 2/ On-demand ARS (address range scrub):
    Linux uses the results of the ACPI ARS commands to track bad blocks
    in pmem devices.  When latent errors are detected we re-scrub the media
    to refresh the bad block list, userspace can also request a re-scrub at
    any time.
 
 3/ Support for the Microsoft DSM (device specific method) command format.
 
 4/ Support for EDK2/OVMF virtual disk device memory ranges.
 
 5/ Various fixes and cleanups across the subsystem.
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Merge tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:

 - Replace pcommit with ADR / directed-flushing.

   The pcommit instruction, which has not shipped on any product, is
   deprecated.  Instead, the requirement is that platforms implement
   either ADR, or provide one or more flush addresses per nvdimm.

   ADR (Asynchronous DRAM Refresh) flushes data in posted write buffers
   to the memory controller on a power-fail event.

   Flush addresses are defined in ACPI 6.x as an NVDIMM Firmware
   Interface Table (NFIT) sub-structure: "Flush Hint Address Structure".
   A flush hint is an mmio address that when written and fenced assures
   that all previous posted writes targeting a given dimm have been
   flushed to media.

 - On-demand ARS (address range scrub).

   Linux uses the results of the ACPI ARS commands to track bad blocks
   in pmem devices.  When latent errors are detected we re-scrub the
   media to refresh the bad block list, userspace can also request a
   re-scrub at any time.

 - Support for the Microsoft DSM (device specific method) command
   format.

 - Support for EDK2/OVMF virtual disk device memory ranges.

 - Various fixes and cleanups across the subsystem.

* tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (41 commits)
  libnvdimm-btt: Delete an unnecessary check before the function call "__nd_device_register"
  nfit: do an ARS scrub on hitting a latent media error
  nfit: move to nfit/ sub-directory
  nfit, libnvdimm: allow an ARS scrub to be triggered on demand
  libnvdimm: register nvdimm_bus devices with an nd_bus driver
  pmem: clarify a debug print in pmem_clear_poison
  x86/insn: remove pcommit
  Revert "KVM: x86: add pcommit support"
  nfit, tools/testing/nvdimm/: unify shutdown paths
  libnvdimm: move ->module to struct nvdimm_bus_descriptor
  nfit: cleanup acpi_nfit_init calling convention
  nfit: fix _FIT evaluation memory leak + use after free
  tools/testing/nvdimm: add manufacturing_{date|location} dimm properties
  tools/testing/nvdimm: add virtual ramdisk range
  acpi, nfit: treat virtual ramdisk SPA as pmem region
  pmem: kill __pmem address space
  pmem: kill wmb_pmem()
  libnvdimm, pmem: use nvdimm_flush() for namespace I/O writes
  fs/dax: remove wmb_pmem()
  libnvdimm, pmem: flush posted-write queues on shutdown
  ...
2016-07-28 17:38:16 -07:00
Linus Torvalds
37e13a1ebe Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "This tree contains tooling fixes plus some additions:

   - fixes to the vdso2c build environment that Stephen Rothwell is
     using for the linux-next build (Arnaldo Carvalho de Melo)

   - AVX-512 instruction mappings (Adrian Hunter)

   - misc fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "perf tools: event.h needs asm/perf_regs.h"
  x86: Make the vdso2c compiler use the host architecture headers
  tools build: Fix objtool build with ARCH=x86_64
  objtool: Always use host headers
  objtool: Use tools/scripts/Makefile.arch to get ARCH and HOSTARCH
  tools build: Add HOSTARCH Makefile variable
  perf tests kmod-path: Fix build on ubuntu:16.04-x-armhf
  perf tools: Add AVX-512 instructions to the new instructions test
  perf tools: Add AVX-512 support to the instruction decoder used by Intel PT
  x86/insn: Add AVX-512 support to the instruction decoder
  x86/insn: perf tools: Fix vcvtph2ps instruction decoding
2016-07-26 10:26:29 -07:00
Linus Torvalds
77cd3d0c43 Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Ingo Molnar:
 "The main changes:

   - add initial commits to randomize kernel memory section virtual
     addresses, enabled via a new kernel option: RANDOMIZE_MEMORY
     (Thomas Garnier, Kees Cook, Baoquan He, Yinghai Lu)

   - enhance KASLR (RANDOMIZE_BASE) physical memory randomization (Kees
     Cook)

   - EBDA/BIOS region boot quirk cleanups (Andy Lutomirski, Ingo Molnar)

   - misc cleanups/fixes"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Simplify EBDA-vs-BIOS reservation logic
  x86/boot: Clarify what x86_legacy_features.reserve_bios_regions does
  x86/boot: Reorganize and clean up the BIOS area reservation code
  x86/mm: Do not reference phys addr beyond kernel
  x86/mm: Add memory hotplug support for KASLR memory randomization
  x86/mm: Enable KASLR for vmalloc memory regions
  x86/mm: Enable KASLR for physical mapping memory regions
  x86/mm: Implement ASLR for kernel memory regions
  x86/mm: Separate variable for trampoline PGD
  x86/mm: Add PUD VA support for physical mapping
  x86/mm: Update physical mapping variable names
  x86/mm: Refactor KASLR entropy functions
  x86/KASLR: Fix boot crash with certain memory configurations
  x86/boot/64: Add forgotten end of function marker
  x86/KASLR: Allow randomization below the load address
  x86/KASLR: Extend kernel image physical address randomization to addresses larger than 4G
  x86/KASLR: Randomize virtual address separately
  x86/KASLR: Clarify identity map interface
  x86/boot: Refuse to build with data relocations
  x86/KASLR, x86/power: Remove x86 hibernation restrictions
2016-07-25 17:32:28 -07:00
Dan Williams
fd1d961dd6 x86/insn: remove pcommit
The pcommit instruction is being deprecated in favor of either ADR
(asynchronous DRAM refresh: flush-on-power-fail) at the platform level, or
posted-write-queue flush addresses as defined by the ACPI 6.x NFIT (NVDIMM
Firmware Interface Table).

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-07-23 11:04:23 -07:00
Adrian Hunter
25af37f4e1 x86/insn: Add AVX-512 support to the instruction decoder
Add support for Intel's AVX-512 instructions to the instruction decoder.

AVX-512 instructions are documented in Intel Architecture Instruction
Set Extensions Programming Reference (February 2016).

AVX-512 instructions are identified by a EVEX prefix which, for the
purpose of instruction decoding, can be treated as though it were a
4-byte VEX prefix.

Existing instructions which can now accept an EVEX prefix need not be
further annotated in the op code map (x86-opcode-map.txt). In the case
of new instructions, the op code map is updated accordingly.

Also add associated Mask Instructions that are used to manipulate mask
registers used in AVX-512 instructions.

The 'perf tools' instruction decoder is updated in a subsequent patch.
And a representative set of instructions is added to the perf tools new
instructions test in a subsequent patch.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: X86 ML <x86@kernel.org>
Link: http://lkml.kernel.org/r/1469003437-32706-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-21 09:37:11 -03:00
Adrian Hunter
6f6ef07f41 x86/insn: perf tools: Fix vcvtph2ps instruction decoding
vcvtph2ps does not have an immediate operand, so remove the erroneous
'Ib' from its opcode map entry. Add vcvtph2ps to the perf tools new
instructions test to verify it.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: X86 ML <x86@kernel.org>
Link: http://lkml.kernel.org/r/1469003437-32706-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-20 09:57:46 -03:00
Andy Lutomirski
13d4ea097d x86/uaccess: Move thread_info::addr_limit to thread_struct
struct thread_info is a legacy mess.  To prepare for its partial removal,
move thread_info::addr_limit out.

As an added benefit, this way is simpler.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/15bee834d09402b47ac86f2feccdf6529f9bc5b0.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-15 10:26:30 +02:00
Paul Gortmaker
e683014c21 x86/lib: Audit and remove any unnecessary uses of module.h
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed.  Build testing
revealed a couple implicit header usage issues that were fixed.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160714001901.31603-5-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 15:06:58 +02:00
Thomas Garnier
d899a7d146 x86/mm: Refactor KASLR entropy functions
Move the KASLR entropy functions into arch/x86/lib to be used in early
kernel boot for KASLR memory randomization.

Signed-off-by: Thomas Garnier <thgarnie@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Kuleshov <kuleshovmail@gmail.com>
Cc: Alexander Popov <alpopov@ptsecurity.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/1466556426-32664-2-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-08 17:33:45 +02:00
Borislav Petkov
f5967101e9 x86/hweight: Get rid of the special calling convention
People complained about ARCH_HWEIGHT_CFLAGS and how it throws a wrench
into kcov, lto, etc, experimentations.

Add asm versions for __sw_hweight{32,64}() and do explicit saving and
restoring of clobbered registers. This gets rid of the special calling
convention. We get to call those functions on !X86_FEATURE_POPCNT CPUs.

We still need to hardcode POPCNT and register operands as some old gas
versions which we support, do not know about POPCNT.

Btw, remove redundant REX prefix from 32-bit POPCNT because alternatives
can do padding now.

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1464605787-20603-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-08 15:01:02 +02:00
Linus Torvalds
168f1a7163 Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
 "The main changes in this cycle were:

   - MSR access API fixes and enhancements (Andy Lutomirski)

   - early exception handling improvements (Andy Lutomirski)

   - user-space FS/GS prctl usage fixes and improvements (Andy
     Lutomirski)

   - Remove the cpu_has_*() APIs and replace them with equivalents
     (Borislav Petkov)

   - task switch micro-optimization (Brian Gerst)

   - 32-bit entry code simplification (Denys Vlasenko)

   - enhance PAT handling in enumated CPUs (Toshi Kani)

  ... and lots of other cleanups/fixlets"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  x86/arch_prctl/64: Restore accidentally removed put_cpu() in ARCH_SET_GS
  x86/entry/32: Remove asmlinkage_protect()
  x86/entry/32: Remove GET_THREAD_INFO() from entry code
  x86/entry, sched/x86: Don't save/restore EFLAGS on task switch
  x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs
  selftests/x86/ldt_gdt: Test set_thread_area() deletion of an active segment
  x86/tls: Synchronize segment registers in set_thread_area()
  x86/asm/64: Rename thread_struct's fs and gs to fsbase and gsbase
  x86/arch_prctl/64: Remove FSBASE/GSBASE < 4G optimization
  x86/segments/64: When load_gs_index fails, clear the base
  x86/segments/64: When loadsegment(fs, ...) fails, clear the base
  x86/asm: Make asm/alternative.h safe from assembly
  x86/asm: Stop depending on ptrace.h in alternative.h
  x86/entry: Rename is_{ia32,x32}_task() to in_{ia32,x32}_syscall()
  x86/asm: Make sure verify_cpu() has a good stack
  x86/extable: Add a comment about early exception handlers
  x86/msr: Set the return value to zero when native_rdmsr_safe() fails
  x86/paravirt: Make "unsafe" MSR accesses unsafe even if PARAVIRT=y
  x86/paravirt: Add paravirt_{read,write}_msr()
  x86/msr: Carry on after a non-"safe" MSR access fails
  ...
2016-05-16 15:15:17 -07:00
Borislav Petkov
4544ba8c6b locking/rwsem: Fix comment on register clobbering
Document explicitly that %edx can get clobbered on the slow path, on
32-bit kernels. Something I learned the hard way. :-\

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-next@vger.kernel.org
Link: http://lkml.kernel.org/r/20160516093428.GA26108@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-16 12:35:40 +02:00
Michal Hocko
00fb16e26a locking/rwsem, x86: Add frame annotation for call_rwsem_down_write_failed_killable()
3387a535ce ("x86/asm: Create stack frames in rwsem functions") has
added FRAME_{BEGIN,END} annotations to rwsem asm stubs. The patch
which has added call_rwsem_down_write_failed_killable() was based on an
older tree so it didn't know about annotations. Let's add them.

This addresses the following objtool warning:

  arch/x86/lib/rwsem.o: warning: objtool: call_rwsem_down_write_failed_killable()+0xe: call without frame pointer save/setup

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1460541432-21631-1-git-send-email-mhocko@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-22 08:58:41 +02:00
Michal Hocko
664b4e24c6 locking/rwsem, x86: Provide __down_write_killable()
which uses the same fast path as __down_write() except it falls back to
call_rwsem_down_write_failed_killable() slow path and return -EINTR if
killed. To prevent from code duplication extract the skeleton of
__down_write() into a helper macro which just takes the semaphore
and the slow path function to be called.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Signed-off-by: Jason Low <jason.low2@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1460041951-22347-11-git-send-email-mhocko@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13 10:42:22 +02:00
Borislav Petkov
054efb6467 x86/cpufeature: Remove cpu_has_xmm2
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-crypto@vger.kernel.org
Link: http://lkml.kernel.org/r/1459266123-21878-8-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31 13:35:09 +02:00
Linus Torvalds
d88f48e128 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - fix hotplug bugs
   - fix irq live lock
   - fix various topology handling bugs
   - fix APIC ACK ordering
   - fix PV iopl handling
   - fix speling
   - fix/tweak memcpy_mcsafe() return value
   - fix fbcon bug
   - remove stray prototypes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/msr: Remove unused native_read_tscp()
  x86/apic: Remove declaration of unused hw_nmi_is_cpu_stuck
  x86/oprofile/nmi: Add missing hotplug FROZEN handling
  x86/hpet: Use proper mask to modify hotplug action
  x86/apic/uv: Fix the hotplug notifier
  x86/apb/timer: Use proper mask to modify hotplug action
  x86/topology: Use total_cpus not nr_cpu_ids for logical packages
  x86/topology: Fix Intel HT disable
  x86/topology: Fix logical package mapping
  x86/irq: Cure live lock in fixup_irqs()
  x86/tsc: Prevent NULL pointer deref in calibrate_delay_is_known()
  x86/apic: Fix suspicious RCU usage in smp_trace_call_function_interrupt()
  x86/iopl: Fix iopl capability check on Xen PV
  x86/iopl/64: Properly context-switch IOPL on Xen PV
  selftests/x86: Add an iopl test
  x86/mm, x86/mce: Fix return type/value for memcpy_mcsafe()
  x86/video: Don't assume all FB devices are PCI devices
  arch/x86/irq: Purge useless handler declarations from hw_irq.h
  x86: Fix misspellings in comments
2016-03-24 09:47:32 -07:00
Dmitry Vyukov
5c9a8750a6 kernel: add kcov code coverage
kcov provides code coverage collection for coverage-guided fuzzing
(randomized testing).  Coverage-guided fuzzing is a testing technique
that uses coverage feedback to determine new interesting inputs to a
system.  A notable user-space example is AFL
(http://lcamtuf.coredump.cx/afl/).  However, this technique is not
widely used for kernel testing due to missing compiler and kernel
support.

kcov does not aim to collect as much coverage as possible.  It aims to
collect more or less stable coverage that is function of syscall inputs.
To achieve this goal it does not collect coverage in soft/hard
interrupts and instrumentation of some inherently non-deterministic or
non-interesting parts of kernel is disbled (e.g.  scheduler, locking).

Currently there is a single coverage collection mode (tracing), but the
API anticipates additional collection modes.  Initially I also
implemented a second mode which exposes coverage in a fixed-size hash
table of counters (what Quentin used in his original patch).  I've
dropped the second mode for simplicity.

This patch adds the necessary support on kernel side.  The complimentary
compiler support was added in gcc revision 231296.

We've used this support to build syzkaller system call fuzzer, which has
found 90 kernel bugs in just 2 months:

  https://github.com/google/syzkaller/wiki/Found-Bugs

We've also found 30+ bugs in our internal systems with syzkaller.
Another (yet unexplored) direction where kcov coverage would greatly
help is more traditional "blob mutation".  For example, mounting a
random blob as a filesystem, or receiving a random blob over wire.

Why not gcov.  Typical fuzzing loop looks as follows: (1) reset
coverage, (2) execute a bit of code, (3) collect coverage, repeat.  A
typical coverage can be just a dozen of basic blocks (e.g.  an invalid
input).  In such context gcov becomes prohibitively expensive as
reset/collect coverage steps depend on total number of basic
blocks/edges in program (in case of kernel it is about 2M).  Cost of
kcov depends only on number of executed basic blocks/edges.  On top of
that, kernel requires per-thread coverage because there are always
background threads and unrelated processes that also produce coverage.
With inlined gcov instrumentation per-thread coverage is not possible.

kcov exposes kernel PCs and control flow to user-space which is
insecure.  But debugfs should not be mapped as user accessible.

Based on a patch by Quentin Casasnovas.

[akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode']
[akpm@linux-foundation.org: unbreak allmodconfig]
[akpm@linux-foundation.org: follow x86 Makefile layout standards]
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Tavis Ormandy <taviso@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@google.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: David Drysdale <drysdale@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-22 15:36:02 -07:00
Linus Torvalds
26660a4046 Merge branch 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull 'objtool' stack frame validation from Ingo Molnar:
 "This tree adds a new kernel build-time object file validation feature
  (ONFIG_STACK_VALIDATION=y): kernel stack frame correctness validation.
  It was written by and is maintained by Josh Poimboeuf.

  The motivation: there's a category of hard to find kernel bugs, most
  of them in assembly code (but also occasionally in C code), that
  degrades the quality of kernel stack dumps/backtraces.  These bugs are
  hard to detect at the source code level.  Such bugs result in
  incorrect/incomplete backtraces most of time - but can also in some
  rare cases result in crashes or other undefined behavior.

  The build time correctness checking is done via the new 'objtool'
  user-space utility that was written for this purpose and which is
  hosted in the kernel repository in tools/objtool/.  The tool's (very
  simple) UI and source code design is shaped after Git and perf and
  shares quite a bit of infrastructure with tools/perf (which tooling
  infrastructure sharing effort got merged via perf and is already
  upstream).  Objtool follows the well-known kernel coding style.

  Objtool does not try to check .c or .S files, it instead analyzes the
  resulting .o generated machine code from first principles: it decodes
  the instruction stream and interprets it.  (Right now objtool supports
  the x86-64 architecture.)

  From tools/objtool/Documentation/stack-validation.txt:

   "The kernel CONFIG_STACK_VALIDATION option enables a host tool named
    objtool which runs at compile time.  It has a "check" subcommand
    which analyzes every .o file and ensures the validity of its stack
    metadata.  It enforces a set of rules on asm code and C inline
    assembly code so that stack traces can be reliable.

    Currently it only checks frame pointer usage, but there are plans to
    add CFI validation for C files and CFI generation for asm files.

    For each function, it recursively follows all possible code paths
    and validates the correct frame pointer state at each instruction.

    It also follows code paths involving special sections, like
    .altinstructions, __jump_table, and __ex_table, which can add
    alternative execution paths to a given instruction (or set of
    instructions).  Similarly, it knows how to follow switch statements,
    for which gcc sometimes uses jump tables."

  When this new kernel option is enabled (it's disabled by default), the
  tool, if it finds any suspicious assembly code pattern, outputs
  warnings in compiler warning format:

    warning: objtool: rtlwifi_rate_mapping()+0x2e7: frame pointer state mismatch
    warning: objtool: cik_tiling_mode_table_init()+0x6ce: call without frame pointer save/setup
    warning: objtool:__schedule()+0x3c0: duplicate frame pointer save
    warning: objtool:__schedule()+0x3fd: sibling call from callable instruction with changed frame pointer

  ... so that scripts that pick up compiler warnings will notice them.
  All known warnings triggered by the tool are fixed by the tree, most
  of the commits in fact prepare the kernel to be warning-free.  Most of
  them are bugfixes or cleanups that stand on their own, but there are
  also some annotations of 'special' stack frames for justified cases
  such entries to JIT-ed code (BPF) or really special boot time code.

  There are two other long-term motivations behind this tool as well:

   - To improve the quality and reliability of kernel stack frames, so
     that they can be used for optimized live patching.

   - To create independent infrastructure to check the correctness of
     CFI stack frames at build time.  CFI debuginfo is notoriously
     unreliable and we cannot use it in the kernel as-is without extra
     checking done both on the kernel side and on the build side.

  The quality of kernel stack frames matters to debuggability as well,
  so IMO we can merge this without having to consider the live patching
  or CFI debuginfo angle"

* 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  objtool: Only print one warning per function
  objtool: Add several performance improvements
  tools: Copy hashtable.h into tools directory
  objtool: Fix false positive warnings for functions with multiple switch statements
  objtool: Rename some variables and functions
  objtool: Remove superflous INIT_LIST_HEAD
  objtool: Add helper macros for traversing instructions
  objtool: Fix false positive warnings related to sibling calls
  objtool: Compile with debugging symbols
  objtool: Detect infinite recursion
  objtool: Prevent infinite recursion in noreturn detection
  objtool: Detect and warn if libelf is missing and don't break the build
  tools: Support relative directory path for 'O='
  objtool: Support CROSS_COMPILE
  x86/asm/decoder: Use explicitly signed chars
  objtool: Enable stack metadata validation on 64-bit x86
  objtool: Add CONFIG_STACK_VALIDATION option
  objtool: Add tool to perform compile-time stack metadata validation
  x86/kprobes: Mark kretprobe_trampoline() stack frame as non-standard
  sched: Always inline context_switch()
  ...
2016-03-20 18:23:21 -07:00
Linus Torvalds
1200b6809d Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "Highlights:

   1) Support more Realtek wireless chips, from Jes Sorenson.

   2) New BPF types for per-cpu hash and arrap maps, from Alexei
      Starovoitov.

   3) Make several TCP sysctls per-namespace, from Nikolay Borisov.

   4) Allow the use of SO_REUSEPORT in order to do per-thread processing
   of incoming TCP/UDP connections.  The muxing can be done using a
   BPF program which hashes the incoming packet.  From Craig Gallek.

   5) Add a multiplexer for TCP streams, to provide a messaged based
      interface.  BPF programs can be used to determine the message
      boundaries.  From Tom Herbert.

   6) Add 802.1AE MACSEC support, from Sabrina Dubroca.

   7) Avoid factorial complexity when taking down an inetdev interface
      with lots of configured addresses.  We were doing things like
      traversing the entire address less for each address removed, and
      flushing the entire netfilter conntrack table for every address as
      well.

   8) Add and use SKB bulk free infrastructure, from Jesper Brouer.

   9) Allow offloading u32 classifiers to hardware, and implement for
      ixgbe, from John Fastabend.

  10) Allow configuring IRQ coalescing parameters on a per-queue basis,
      from Kan Liang.

  11) Extend ethtool so that larger link mode masks can be supported.
      From David Decotigny.

  12) Introduce devlink, which can be used to configure port link types
      (ethernet vs Infiniband, etc.), port splitting, and switch device
      level attributes as a whole.  From Jiri Pirko.

  13) Hardware offload support for flower classifiers, from Amir Vadai.

  14) Add "Local Checksum Offload".  Basically, for a tunneled packet
      the checksum of the outer header is 'constant' (because with the
      checksum field filled into the inner protocol header, the payload
      of the outer frame checksums to 'zero'), and we can take advantage
      of that in various ways.  From Edward Cree"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits)
  bonding: fix bond_get_stats()
  net: bcmgenet: fix dma api length mismatch
  net/mlx4_core: Fix backward compatibility on VFs
  phy: mdio-thunder: Fix some Kconfig typos
  lan78xx: add ndo_get_stats64
  lan78xx: handle statistics counter rollover
  RDS: TCP: Remove unused constant
  RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket
  net: smc911x: convert pxa dma to dmaengine
  team: remove duplicate set of flag IFF_MULTICAST
  bonding: remove duplicate set of flag IFF_MULTICAST
  net: fix a comment typo
  ethernet: micrel: fix some error codes
  ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it
  bpf, dst: add and use dst_tclassid helper
  bpf: make skb->tc_classid also readable
  net: mvneta: bm: clarify dependencies
  cls_bpf: reset class and reuse major in da
  ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c
  ldmvsw: Add ldmvsw.c driver code
  ...
2016-03-19 10:05:34 -07:00
Ingo Molnar
00f5268501 Merge branch 'x86/cleanups' into x86/urgent
Pull in some merge window leftovers.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-17 09:44:57 +01:00
Tony Luck
cbf8b5a2b6 x86/mm, x86/mce: Fix return type/value for memcpy_mcsafe()
Returning a 'bool' was very unpopular. Doubly so because the
code was just wrong (returning zero for true, one for false;
great for shell programming, not so good for C).

Change return type to "int". Keep zero as the success indicator
because it matches other similar code and people may be more
comfortable writing:

	if (memcpy_mcsafe(to, from, count)) {
		printk("Sad panda, copy failed\n");
		...
	}

Make the failure return value -EFAULT for now.

Reported by: Mika Penttilä <mika.penttila@nextfour.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mika.penttila@nextfour.com
Fixes: 92b0729c34 ("x86/mm, x86/mce: Add memcpy_mcsafe()")
Link: http://lkml.kernel.org/r/695f14233fa7a54fcac4406c706d7fec228e3f4c.1457993040.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-16 09:02:18 +01:00
Linus Torvalds
42576bee6e Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Ingo Molnar:
 "Early command line options parsing enhancements from Dave Hansen, plus
  minor cleanups and enhancements"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Remove unused 'is_big_kernel' variable
  x86/boot: Use proper array element type in memset() size calculation
  x86/boot: Pass in size to early cmdline parsing
  x86/boot: Simplify early command line parsing
  x86/boot: Fix early command-line parsing when partial word matches
  x86/boot: Fix early command-line parsing when matching at end
  x86/boot: Simplify kernel load address alignment check
  x86/boot: Micro-optimize reset_early_page_tables()
2016-03-15 10:02:25 -07:00
Linus Torvalds
ba33ea811e Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
 "This is another big update. Main changes are:

   - lots of x86 system call (and other traps/exceptions) entry code
     enhancements.  In particular the complex parts of the 64-bit entry
     code have been migrated to C code as well, and a number of dusty
     corners have been refreshed.  (Andy Lutomirski)

   - vDSO special mapping robustification and general cleanups (Andy
     Lutomirski)

   - cpufeature refactoring, cleanups and speedups (Borislav Petkov)

   - lots of other changes ..."

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  x86/cpufeature: Enable new AVX-512 features
  x86/entry/traps: Show unhandled signal for i386 in do_trap()
  x86/entry: Call enter_from_user_mode() with IRQs off
  x86/entry/32: Change INT80 to be an interrupt gate
  x86/entry: Improve system call entry comments
  x86/entry: Remove TIF_SINGLESTEP entry work
  x86/entry/32: Add and check a stack canary for the SYSENTER stack
  x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixup
  x86/entry: Only allocate space for tss_struct::SYSENTER_stack if needed
  x86/entry: Vastly simplify SYSENTER TF (single-step) handling
  x86/entry/traps: Clear DR6 early in do_debug() and improve the comment
  x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptions
  x86/entry/32: Restore FLAGS on SYSEXIT
  x86/entry/32: Filter NT and speed up AC filtering in SYSENTER
  x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test
  selftests/x86: In syscall_nt, test NT|TF as well
  x86/asm-offsets: Remove PARAVIRT_enabled
  x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled
  uprobes: __create_xol_area() must nullify xol_mapping.fault
  x86/cpufeature: Create a new synthetic cpu capability for machine check recovery
  ...
2016-03-15 09:32:27 -07:00
Linus Torvalds
d88bfe1d68 Merge branch 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS updates from Ingo Molnar:
 "Various RAS updates:

   - AMD MCE support updates for future CPUs, fixes and 'SMCA' (Scalable
     MCA) error decoding support (Aravind Gopalakrishnan)

   - x86 memcpy_mcsafe() support, to enable smart(er) hardware error
     recovery in NVDIMM drivers, based on an extension of the x86
     exception handling code.  (Tony Luck)"

* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  EDAC/sb_edac: Fix computation of channel address
  x86/mm, x86/mce: Add memcpy_mcsafe()
  x86/mce/AMD: Document some functionality
  x86/mce: Clarify comments regarding deferred error
  x86/mce/AMD: Fix logic to obtain block address
  x86/mce/AMD, EDAC: Enable error decoding of Scalable MCA errors
  x86/mce: Move MCx_CONFIG MSR definitions
  x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries
  x86/mm: Expand the exception table logic to allow new handling options
  x86/mce/AMD: Set MCAX Enable bit
  x86/mce/AMD: Carve out threshold block preparation
  x86/mce/AMD: Fix LVT offset configuration for thresholding
  x86/mce/AMD: Reduce number of blocks scanned per bank
  x86/mce/AMD: Do not perform shared bank check for future processors
  x86/mce: Fix order of AMD MCE init function call
2016-03-14 18:43:51 -07:00
Alexander Duyck
1e94082963 ipv6: Pass proto to csum_ipv6_magic as __u8 instead of unsigned short
This patch updates csum_ipv6_magic so that it correctly recognizes that
protocol is a unsigned 8 bit value.

This will allow us to better understand what limitations may or may not be
present in how we handle the data.  For example there are a number of
places that call htonl on the protocol value.  This is likely not necessary
and can be replaced with a multiplication by ntohl(1) which will be
converted to a shift by the compiler.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-13 23:55:13 -04:00
Borislav Petkov
84477336ec x86/delay: Avoid preemptible context checks in delay_mwaitx()
We do use this_cpu_ptr(&cpu_tss) as a cacheline-aligned, seldomly
accessed per-cpu var as the MONITORX target in delay_mwaitx(). However,
when called in preemptible context, this_cpu_ptr -> smp_processor_id() ->
debug_smp_processor_id() fires:

  BUG: using smp_processor_id() in preemptible [00000000] code: udevd/312
  caller is delay_mwaitx+0x40/0xa0

But we don't care about that check - we only need cpu_tss as a MONITORX
target and it doesn't really matter which CPU's var we're touching as
we're going idle anyway. Fix that.

Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: spg_linux_kernel@amd.com
Link: http://lkml.kernel.org/r/20160309205622.GG6564@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 11:27:12 +01:00
Tony Luck
92b0729c34 x86/mm, x86/mce: Add memcpy_mcsafe()
Make use of the EXTABLE_FAULT exception table entries to write
a kernel copy routine that doesn't crash the system if it
encounters a machine check. Prime use case for this is to copy
from large arrays of non-volatile memory used as storage.

We have to use an unrolled copy loop for now because current
hardware implementations treat a machine check in "rep mov"
as fatal. When that is fixed we can simplify.

Return type is a "bool". True means that we copied OK, false means
that it didn't.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@gmail.com>
Link: http://lkml.kernel.org/r/a44e1055efc2d2a9473307b22c91caa437aa3f8b.1456439214.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-08 17:54:38 +01:00
Josh Poimboeuf
19072f23d1 x86/asm/decoder: Use explicitly signed chars
When running objtool on a ppc64le host to analyze x86 binaries, it
reports a lot of false warnings like:

  ipc/compat_mq.o: warning: objtool: compat_SyS_mq_open()+0x91: can't find jump dest instruction at .text+0x3a5

The warnings are caused by the x86 instruction decoder setting the wrong
value for the jump instruction's immediate field because it assumes that
"char == signed char", which isn't true for all architectures.  When
converting char to int, gcc sign-extends on x86 but doesn't sign-extend
on ppc64le.

According to the gcc man page, that's a feature, not a bug:

  > Each kind of machine has a default for what "char" should be.  It is
  > either like "unsigned char" by default or like "signed char" by
  > default.
  >
  > Ideally, a portable program should always use "signed char" or
  > "unsigned char" when it depends on the signedness of an object.

Conform to the "standards" by changing the "char" casts to "signed
char".  This results in no actual changes to the object code on x86.

Note: the x86 decoder now lives in three different locations in the
kernel tree, which are all kept in sync via makefile checks and
warnings: in-kernel, perf, and objtool.  This fixes all three locations.
Eventually we should probably try to at least converge the two separate
"tools" locations into a single shared location.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/9dd4161719b20e6def9564646d68bfbe498c549f.1456962210.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-03 16:13:00 +01:00
Adam Buchbinder
6a6256f9e0 x86: Fix misspellings in comments
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: trivial@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-24 08:44:58 +01:00
Josh Poimboeuf
3387a535ce x86/asm: Create stack frames in rwsem functions
rwsem.S has several callable non-leaf functions which don't honor
CONFIG_FRAME_POINTER, which can result in bad stack traces.

Create stack frames for them when CONFIG_FRAME_POINTER is enabled.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/ad0932bbead975b15f9578e4f2cf2ee5961eb840.1453405861.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-24 08:35:43 +01:00
Ingo Molnar
3a2f2ac9b9 Merge branch 'x86/urgent' into x86/asm, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-18 09:28:03 +01:00
Toshi Kani
a82eee7424 x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache()
Data corruption issues were observed in tests which initiated
a system crash/reset while accessing BTT devices.  This problem
is reproducible.

The BTT driver calls pmem_rw_bytes() to update data in pmem
devices.  This interface calls __copy_user_nocache(), which
uses non-temporal stores so that the stores to pmem are
persistent.

__copy_user_nocache() uses non-temporal stores when a request
size is 8 bytes or larger (and is aligned by 8 bytes).  The
BTT driver updates the BTT map table, which entry size is
4 bytes.  Therefore, updates to the map table entries remain
cached, and are not written to pmem after a crash.

Change __copy_user_nocache() to use non-temporal store when
a request size is 4 bytes.  The change extends the current
byte-copy path for a less-than-8-bytes request, and does not
add any overhead to the regular path.

Reported-and-tested-by: Micah Parrish <micah.parrish@hpe.com>
Reported-and-tested-by: Brian Boylston <brian.boylston@hpe.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: <stable@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/1455225857-12039-3-git-send-email-toshi.kani@hpe.com
[ Small readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 09:10:23 +01:00
Toshi Kani
ee9737c924 x86/uaccess/64: Make the __copy_user_nocache() assembly code more readable
Add comments to __copy_user_nocache() to clarify its procedures
and alignment requirements.

Also change numeric branch target labels to named local labels.

No code changed:

 arch/x86/lib/copy_user_64.o:

    text    data     bss     dec     hex filename
    1239       0       0    1239     4d7 copy_user_64.o.before
    1239       0       0    1239     4d7 copy_user_64.o.after

 md5:
    58bed94c2db98c1ca9a2d46d0680aaae  copy_user_64.o.before.asm
    58bed94c2db98c1ca9a2d46d0680aaae  copy_user_64.o.after.asm

Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: <stable@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: brian.boylston@hpe.com
Cc: dan.j.williams@intel.com
Cc: linux-nvdimm@lists.01.org
Cc: micah.parrish@hpe.com
Cc: ross.zwisler@linux.intel.com
Cc: vishal.l.verma@intel.com
Link: http://lkml.kernel.org/r/1455225857-12039-2-git-send-email-toshi.kani@hpe.com
[ Small readability edits and added object file comparison. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 09:10:22 +01:00
Dave Hansen
8c0517759a x86/boot: Pass in size to early cmdline parsing
We will use this in a few patches to implement tests for early parsing.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
[ Aligned args properly. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20151222225243.5CC47EB6@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-03 12:03:18 +01:00
Dave Hansen
4de07ea481 x86/boot: Simplify early command line parsing
__cmdline_find_option_bool() tries to account for both NULL-terminated
and non-NULL-terminated strings. It keeps 'pos' to look for the end of
the buffer and also looks for '!c' in a bunch of places to look for NULL
termination.

But, it also calls strlen(). You can't call strlen on a
non-NULL-terminated string.

If !strlen(cmdline), then cmdline[0]=='\0'. In that case, we will go in
to the while() loop, set c='\0', hit st_wordstart, notice !c, and will
immediately return 0.

So, remove the strlen().  It is unnecessary and unsafe.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20151222225241.15365E43@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-03 12:03:17 +01:00
Dave Hansen
abcdc1c694 x86/boot: Fix early command-line parsing when partial word matches
cmdline_find_option_bool() keeps track of position in two strings:

 1. the command-line
 2. the option we are searchign for in the command-line

We plow through each character in the command-line one at a time, always
moving forward. We move forward in the option ('opptr') when we match
characters in 'cmdline'. We reset the 'opptr' only when we go in to the
'st_wordstart' state.

But, if we fail to match an option because we see a space
(state=st_wordcmp, *opptr='\0',c=' '), we set state='st_wordskip' and
'break', moving to the next character. But, that move to the next
character is the one *after* the ' '. This means that we will miss a
'st_wordstart' state.

For instance, if we have

  cmdline = "foo fool";

and are searching for "fool", we have:

	  "fool"
  opptr = ----^

           "foo fool"
   c = --------^

We see that 'l' != ' ', set state=st_wordskip, break, and then move 'c', so:

          "foo fool"
  c = ---------^

and are still in state=st_wordskip. We will stay in wordskip until we
have skipped "fool", thus missing the option we were looking for. This
*only* happens when you have a partially- matching word followed by a
matching one.

To fix this, we always fall *into* the 'st_wordskip' state when we set
it.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20151222225239.8E1DCA58@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-03 12:03:16 +01:00
Dave Hansen
02afeaae98 x86/boot: Fix early command-line parsing when matching at end
The x86 early command line parsing in cmdline_find_option_bool() is
buggy. If it matches a specified 'option' all the way to the end of the
command-line, it will consider it a match.

For instance,

  cmdline = "foo";
  cmdline_find_option_bool(cmdline, "fool");

will return 1. This is particularly annoying since we have actual FPU
options like "noxsave" and "noxsaves" So, command-line "foo bar noxsave"
will match *BOTH* a "noxsave" and "noxsaves". (This turns out not to be
an actual problem because "noxsave" implies "noxsaves", but it's still
confusing.)

To fix this, we simplify the code and stop tracking 'len'. 'len'
was trying to indicate either the NULL terminator *OR* the end of a
non-NULL-terminated command line at 'COMMAND_LINE_SIZE'. But, each of the
three states is *already* checking 'cmdline' for a NULL terminator.

We _only_ need to check if we have overrun 'COMMAND_LINE_SIZE', and that
we can do without keeping 'len' around.

Also add some commends to clarify what is going on.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: fenghua.yu@intel.com
Cc: yu-cheng.yu@intel.com
Link: http://lkml.kernel.org/r/20151222225238.9AEB560C@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-03 12:03:15 +01:00
Borislav Petkov
cd4d09ec6f x86/cpufeature: Carve out X86_FEATURE_*
Move them to a separate header and have the following
dependency:

  x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h

This makes it easier to use the header in asm code and not
include the whole cpufeature.h and add guards for asm.

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-30 11:22:17 +01:00
Linus Torvalds
671d5532aa Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Improved CPU ID handling code and related enhancements (Borislav
     Petkov)

   - RDRAND fix (Len Brown)"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Replace RDRAND forced-reseed with simple sanity check
  x86/MSR: Chop off lower 32-bit value
  x86/cpu: Fix MSR value truncation issue
  x86/cpu/amd, kvm: Satisfy guest kernel reads of IC_CFG MSR
  kvm: Add accessors for guest CPU's family, model, stepping
  x86/cpu: Unify CPU family, model, stepping calculation
2016-01-11 16:46:20 -08:00
Andi Kleen
7f47d8cc03 x86, tracing, perf: Add trace point for MSR accesses
For debugging low level code interacting with the CPU it is often
useful to trace the MSR read/writes. This gives a concise summary of
PMU and other operations.

perf has an ad-hoc way to do this using trace_printk, but it's
somewhat limited (and also now spews ugly boot messages when enabled)

Instead define real trace points for all MSR accesses.

This adds three new trace points: read_msr and write_msr and rdpmc.

They also report if the access faulted (if *_safe is used)

This allows filtering and triggering on specific MSR values, which
allows various more advanced debugging techniques.

All the values are well defined in the CPU documentation.

The trace can be post processed with
Documentation/trace/postprocess/decode_msr.py to add symbolic MSR
names to the trace.

I only added it to native MSR accesses in C, not paravirtualized or in
entry*.S (which is not too interesting)

Originally the patch kit moved the MSRs out of line.  This uses an
alternative approach recommended by Steven Rostedt of only moving the
trace calls out of line, but open coding the access to the jump label.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1449018060-1742-3-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-06 12:56:10 +01:00
Borislav Petkov
99f925ce92 x86/cpu: Unify CPU family, model, stepping calculation
Add generic functions which calc family, model and stepping from
the CPUID_1.EAX leaf and stick them into the library we have.

Rename those which do call CPUID with the prefix "x86_cpuid" as
suggested by Paolo Bonzini.

No functionality change.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1448273546-2567-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-24 09:15:54 +01:00
Ingo Molnar
d2bb1d42b9 Linux 4.3-rc1
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Merge tag 'v4.3-rc1' into perf/core, to refresh the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-13 11:25:35 +02:00
Adrian Hunter
f83b6b64eb x86/insn: perf tools: Add new xsave instructions
Add xsavec, xsaves and xrstors to the op code map and the perf tools new
instructions test.  To run the test:

  $ tools/perf/perf test "x86 ins"
  39: Test x86 instruction decoder - new instructions          : Ok

Or to see the details:

  $ tools/perf/perf test -v "x86 ins" 2>&1 | grep 'xsave\|xrst'

For information about xsavec, xsaves and xrstors, refer the Intel SDM.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-04 12:01:04 -03:00
Adrian Hunter
978260cdbe x86/insn: perf tools: Add new memory protection keys instructions
Add rdpkru and wrpkru to the op code map and the perf tools new
instructions test.  In the case of the test, only the bytes can be
tested at the moment since binutils doesn't support the instructions
yet.  To run the test:

  $ tools/perf/perf test "x86 ins"
  39: Test x86 instruction decoder - new instructions          : Ok

Or to see the details:

  $ tools/perf/perf test -v "x86 ins" 2>&1 | grep pkru

For information about rdpkru and wrpkru, refer the Intel SDM.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-7-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-04 12:01:03 -03:00
Adrian Hunter
ac1c8859a8 x86/insn: perf tools: Add new memory instructions
Intel Architecture Instruction Set Extensions Programing Reference (Oct
2014) describes 3 new memory instructions, namely clflushopt, clwb and
pcommit.  Add them to the op code map and the perf tools new
instructions test. e.g.

  $ tools/perf/perf test "x86 ins"
  39: Test x86 instruction decoder - new instructions          : Ok

Or to see the details:

  $ tools/perf/perf test -v "x86 ins"

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-04 12:01:03 -03:00
Adrian Hunter
3fe78d6af9 x86/insn: perf tools: Add new SHA instructions
Intel SHA Extensions are explained in the Intel Architecture
Instruction Set Extensions Programing Reference (Oct 2014).
There are 7 new instructions.  Add them to the op code map
and the perf tools new instructions test. e.g.

  $ tools/perf/perf test "x86 ins"
  39: Test x86 instruction decoder - new instructions          : Ok

Or to see the details:

  $ tools/perf/perf test -v "x86 ins" 2>&1 | grep sha

Committer note:

3 lines of details, for the curious:

  $ perf test -v "x86 ins" 2>&1 | grep sha256msg1 | tail -3
  Decoded ok: 0f 38 cc 84 08 78 56 34 12 	sha256msg1 0x12345678(%rax,%rcx,1),%xmm0
  Decoded ok: 0f 38 cc 84 c8 78 56 34 12 	sha256msg1 0x12345678(%rax,%rcx,8),%xmm0
  Decoded ok: 44 0f 38 cc bc c8 78 56 34 12 	sha256msg1 0x12345678(%rax,%rcx,8),%xmm15
  $

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-04 12:01:03 -03:00
Adrian Hunter
78173ec631 x86/insn: perf tools: Pedantically tweak opcode map for MPX instructions
The MPX instructions are presently not described in the SDM
opcode maps, and there are not encoding characters for bnd
registers, address method or operand type.  So the kernel
opcode map is using 'Gv' for bnd registers and 'Ev' for
everything else.  That is fine because the instruction
decoder does not use that information anyway, except as
an indication that there is a ModR/M byte.

Nevertheless, in some cases the 'Gv' and 'Ev' are the wrong
way around, BNDLDX and BNDSTX have 2 operands not 3, and it
wouldn't hurt to identify the mandatory prefixes.

This has no effect on the decoding of valid instructions,
but the addition of the mandatory prefixes will cause some
invalid instructions to error out that wouldn't have
previously.

Note that perf tools has a copy of the instruction decoder
and provides a test for new instructions which includes MPX
instructions e.g.

  $ perf test "x86 ins"
  39: Test x86 instruction decoder - new instructions          : Ok

Or to see the details:

  $ perf test -v "x86 ins"

Commiter notes:

And to see these MPX instructions specifically:

  $ perf test -v "x86 ins" 2>&1 | grep bndldx | head -3
  Decoded ok: 0f 1a 00             	bndldx (%eax),%bnd0
  Decoded ok: 0f 1a 05 78 56 34 12 	bndldx 0x12345678,%bnd0
  Decoded ok: 0f 1a 18             	bndldx (%eax),%bnd3
  $ perf test -v "x86 ins" 2>&1 | grep bndstx | head -3
  Decoded ok: 0f 1b 00             	bndstx %bnd0,(%eax)
  Decoded ok: 0f 1b 05 78 56 34 12 	bndstx %bnd0,0x12345678
  Decoded ok: 0f 1b 18             	bndstx %bnd3,(%eax)
  $

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441196131-20632-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-04 12:01:02 -03:00
Huang Rui
b466bdb614 x86/asm/delay: Introduce an MWAITX-based delay with a configurable timer
MWAITX can enable a timer and a corresponding timer value
specified in SW P0 clocks. The SW P0 frequency is the same as
TSC. The timer provides an upper bound on how long the
instruction waits before exiting.

This way, a delay function in the kernel can leverage that
MWAITX timer of MWAITX.

When a CPU core executes MWAITX, it will be quiesced in a
waiting phase, diminishing its power consumption. This way, we
can save power in comparison to our default TSC-based delays.

A simple test shows that:

	$ cat /sys/bus/pci/devices/0000\:00\:18.4/hwmon/hwmon0/power1_acc
	$ sleep 10000s
	$ cat /sys/bus/pci/devices/0000\:00\:18.4/hwmon/hwmon0/power1_acc

Results:

	* TSC-based default delay:      485115 uWatts average power
	* MWAITX-based delay:           252738 uWatts average power

Thus, that's about 240 milliWatts less power consumption. The
test method relies on the support of AMD CPU accumulated power
algorithm in fam15h_power for which patches are forthcoming.

Suggested-by: Andy Lutomirski <luto@amacapital.net>
Suggested-by: Borislav Petkov <bp@suse.de>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Huang Rui <ray.huang@amd.com>
[ Fix delay truncation. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Andreas Herrmann <herrmann.der.user@gmail.com>
Cc: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Jacob Shin <jacob.w.shin@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Li <tony.li@amd.com>
Link: http://lkml.kernel.org/r/1438744732-1459-3-git-send-email-ray.huang@amd.com
Link: http://lkml.kernel.org/r/1439201994-28067-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-22 14:52:16 +02:00
Ingo Molnar
5b929bd11d Merge branch 'x86/urgent' into x86/asm, before applying dependent patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-31 10:23:35 +02:00
Andy Lutomirski
03b9730b76 x86/asm/tsc: Add rdtsc_ordered() and use it in trivial call sites
rdtsc_barrier(); rdtsc() is an unnecessary mouthful and requires
more thought than should be necessary. Add an rdtsc_ordered()
helper and replace the trivial call sites with it.

This should not change generated code. The duplication of the
fence asm is temporary.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/dddbf98a2af53312e9aa73a5a2b1622fe5d6f52b.1434501121.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06 15:23:29 +02:00
Andy Lutomirski
4ea1636b04 x86/asm/tsc: Rename native_read_tsc() to rdtsc()
Now that there is no paravirt TSC, the "native" is
inappropriate. The function does RDTSC, so give it the obvious
name: rdtsc().

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/fd43e16281991f096c1e4d21574d9e1402c62d39.1434501121.git.luto@kernel.org
[ Ported it to v4.2-rc1. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06 15:23:28 +02:00
Andy Lutomirski
9cfa1a0279 x86/asm/tsc: Use the full 64-bit TSC in delay_tsc()
As a very minor optimization, delay_tsc() was only using the low
32 bits of the TSC. It's a delay function, so just use the whole
thing.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/bd1a277c71321b67c4794970cb5ace05efe21ab6.1434501121.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06 15:23:27 +02:00
Andy Lutomirski
87be28aaf1 x86/asm/tsc: Replace rdtscll() with native_read_tsc()
Now that the ->read_tsc() paravirt hook is gone, rdtscll() is
just a wrapper around native_read_tsc(). Unwrap it.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/d2449ae62c1b1fb90195bcfb19ef4a35883a04dc.1434501121.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06 15:23:26 +02:00
Yann Droneaud
ebf2d2689d perf/x86: Fix copy_from_user_nmi() return if range is not ok
Commit 0a196848ca ("perf: Fix arch_perf_out_copy_user default"),
changes copy_from_user_nmi() to return the number of
remaining bytes so that it behave like copy_from_user().

Unfortunately, when the range is outside of the process
memory, the return value  is still the number of byte
copied, eg. 0, instead of the remaining bytes.

As all users of copy_from_user_nmi() were modified as
part of commit 0a196848ca, the function should be
fixed to return the total number of bytes if range is
not correct.

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435001923-30986-1-git-send-email-ydroneaud@opteya.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-06 14:09:27 +02:00
Linus Torvalds
d70b3ef54c Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Ingo Molnar:
 "There were so many changes in the x86/asm, x86/apic and x86/mm topics
  in this cycle that the topical separation of -tip broke down somewhat -
  so the result is a more traditional architecture pull request,
  collected into the 'x86/core' topic.

  The topics were still maintained separately as far as possible, so
  bisectability and conceptual separation should still be pretty good -
  but there were a handful of merge points to avoid excessive
  dependencies (and conflicts) that would have been poorly tested in the
  end.

  The next cycle will hopefully be much more quiet (or at least will
  have fewer dependencies).

  The main changes in this cycle were:

   * x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
     Gleixner)

     - This is the second and most intrusive part of changes to the x86
       interrupt handling - full conversion to hierarchical interrupt
       domains:

          [IOAPIC domain]   -----
                                 |
          [MSI domain]      --------[Remapping domain] ----- [ Vector domain ]
                                 |   (optional)          |
          [HPET MSI domain] -----                        |
                                                         |
          [DMAR domain]     -----------------------------
                                                         |
          [Legacy domain]   -----------------------------

       This now reflects the actual hardware and allowed us to distangle
       the domain specific code from the underlying parent domain, which
       can be optional in the case of interrupt remapping.  It's a clear
       separation of functionality and removes quite some duct tape
       constructs which plugged the remap code between ioapic/msi/hpet
       and the vector management.

     - Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
       injection into guests (Feng Wu)

   * x86/asm changes:

     - Tons of cleanups and small speedups, micro-optimizations.  This
       is in preparation to move a good chunk of the low level entry
       code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
       Brian Gerst)

     - Moved all system entry related code to a new home under
       arch/x86/entry/ (Ingo Molnar)

     - Removal of the fragile and ugly CFI dwarf debuginfo annotations.
       Conversion to C will reintroduce many of them - but meanwhile
       they are only getting in the way, and the upstream kernel does
       not rely on them (Ingo Molnar)

     - NOP handling refinements. (Borislav Petkov)

   * x86/mm changes:

     - Big PAT and MTRR rework: making the code more robust and
       preparing to phase out exposing direct MTRR interfaces to drivers -
       in favor of using PAT driven interfaces (Toshi Kani, Luis R
       Rodriguez, Borislav Petkov)

     - New ioremap_wt()/set_memory_wt() interfaces to support
       Write-Through cached memory mappings.  This is especially
       important for good performance on NVDIMM hardware (Toshi Kani)

   * x86/ras changes:

     - Add support for deferred errors on AMD (Aravind Gopalakrishnan)

       This is an important RAS feature which adds hardware support for
       poisoned data.  That means roughly that the hardware marks data
       which it has detected as corrupted but wasn't able to correct, as
       poisoned data and raises an APIC interrupt to signal that in the
       form of a deferred error.  It is the OS's responsibility then to
       take proper recovery action and thus prolonge system lifetime as
       far as possible.

     - Add support for Intel "Local MCE"s: upcoming CPUs will support
       CPU-local MCE interrupts, as opposed to the traditional system-
       wide broadcasted MCE interrupts (Ashok Raj)

     - Misc cleanups (Borislav Petkov)

   * x86/platform changes:

     - Intel Atom SoC updates

  ... and lots of other cleanups, fixlets and other changes - see the
  shortlog and the Git log for details"

* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
  x86/hpet: Use proper hpet device number for MSI allocation
  x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
  x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
  x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
  x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
  genirq: Prevent crash in irq_move_irq()
  genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
  iommu, x86: Properly handle posted interrupts for IOMMU hotplug
  iommu, x86: Provide irq_remapping_cap() interface
  iommu, x86: Setup Posted-Interrupts capability for Intel iommu
  iommu, x86: Add cap_pi_support() to detect VT-d PI capability
  iommu, x86: Avoid migrating VT-d posted interrupts
  iommu, x86: Save the mode (posted or remapped) of an IRTE
  iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
  iommu: dmar: Provide helper to copy shared irte fields
  iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
  iommu: Add new member capability to struct irq_remap_ops
  x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
  x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
  x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
  ...
2015-06-22 17:59:09 -07:00
Linus Torvalds
e75c73ad64 Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 FPU updates from Ingo Molnar:
 "This tree contains two main changes:

   - The big FPU code rewrite: wide reaching cleanups and reorganization
     that pulls all the FPU code together into a clean base in
     arch/x86/fpu/.

     The resulting code is leaner and faster, and much easier to
     understand.  This enables future work to further simplify the FPU
     code (such as removing lazy FPU restores).

     By its nature these changes have a substantial regression risk: FPU
     code related bugs are long lived, because races are often subtle
     and bugs mask as user-space failures that are difficult to track
     back to kernel side backs.  I'm aware of no unfixed (or even
     suspected) FPU related regression so far.

   - MPX support rework/fixes.  As this is still not a released CPU
     feature, there were some buglets in the code - should be much more
     robust now (Dave Hansen)"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (250 commits)
  x86/fpu: Fix double-increment in setup_xstate_features()
  x86/mpx: Allow 32-bit binaries on 64-bit kernels again
  x86/mpx: Do not count MPX VMAs as neighbors when unmapping
  x86/mpx: Rewrite the unmap code
  x86/mpx: Support 32-bit binaries on 64-bit kernels
  x86/mpx: Use 32-bit-only cmpxchg() for 32-bit apps
  x86/mpx: Introduce new 'directory entry' to 'addr' helper function
  x86/mpx: Add temporary variable to reduce masking
  x86: Make is_64bit_mm() widely available
  x86/mpx: Trace allocation of new bounds tables
  x86/mpx: Trace the attempts to find bounds tables
  x86/mpx: Trace entry to bounds exception paths
  x86/mpx: Trace #BR exceptions
  x86/mpx: Introduce a boot-time disable flag
  x86/mpx: Restrict the mmap() size check to bounds tables
  x86/mpx: Remove redundant MPX_BNDCFG_ADDR_MASK
  x86/mpx: Clean up the code by not passing a task pointer around when unnecessary
  x86/mpx: Use the new get_xsave_field_ptr()API
  x86/fpu/xstate: Wrap get_xsave_addr() to make it safer
  x86/fpu/xstate: Fix up bad get_xsave_addr() assumptions
  ...
2015-06-22 17:16:11 -07:00
Frederic Weisbecker
4eaca0a887 preempt: Use preempt_schedule_context() as the official tracing preemption point
preempt_schedule_context() is a tracing safe preemption point but it's
only used when CONFIG_CONTEXT_TRACKING=y. Other configs have tracing
recursion issues since commit:

  b30f0e3ffe ("sched/preempt: Optimize preemption operations on __schedule() callers")

introduced function based preemp_count_*() ops.

Lets make it available on all configs and give it a more appropriate
name for its new position.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433432349-1021-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07 15:57:42 +02:00
Ingo Molnar
e6b93f4e48 x86/asm/entry: Move the 'thunk' functions to arch/x86/entry/
These are all calling x86 entry code functions, so move them close
to other entry code.

Change lib-y to obj-y: there's no real difference between the two
as we don't really drop any of them during the linking stage, and
obj-y is the more common approach for core kernel object code.

Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-04 07:37:33 +02:00
Ingo Molnar
131484c8da x86/debug: Remove perpetually broken, unmaintainable dwarf annotations
So the dwarf2 annotations in low level assembly code have
become an increasing hindrance: unreadable, messy macros
mixed into some of the most security sensitive code paths
of the Linux kernel.

These debug info annotations don't even buy the upstream
kernel anything: dwarf driven stack unwinding has caused
problems in the past so it's out of tree, and the upstream
kernel only uses the much more robust framepointers based
stack unwinding method.

In addition to that there's a steady, slow bitrot going
on with these annotations, requiring frequent fixups.
There's no tooling and no functionality upstream that
keeps it correct.

So burn down the sick forest, allowing new, healthier growth:

   27 files changed, 350 insertions(+), 1101 deletions(-)

Someone who has the willingness and time to do this
properly can attempt to reintroduce dwarf debuginfo in x86
assembly code plus dwarf unwinding from first principles,
with the following conditions:

 - it should be maximally readable, and maximally low-key to
   'ordinary' code reading and maintenance.

 - find a build time method to insert dwarf annotations
   automatically in the most common cases, for pop/push
   instructions that manipulate the stack pointer. This could
   be done for example via a preprocessing step that just
   looks for common patterns - plus special annotations for
   the few cases where we want to depart from the default.
   We have hundreds of CFI annotations, so automating most of
   that makes sense.

 - it should come with build tooling checks that ensure that
   CFI annotations are sensible. We've seen such efforts from
   the framepointer side, and there's no reason it couldn't be
   done on the dwarf side.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-02 07:57:48 +02:00
Ingo Molnar
df6b35f409 x86/fpu: Rename i387.h to fpu/api.h
We already have fpu/types.h, move i387.h to fpu/api.h.

The file name has become a misnomer anyway: it offers generic FPU APIs,
but is not limited to i387 functionality.

Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 15:47:30 +02:00
David Hildenbrand
b3c395ef55 mm/uaccess, mm/fault: Clarify that uaccess may only sleep if pagefaults are enabled
In general, non-atomic variants of user access functions must not sleep
if pagefaults are disabled.

Let's update all relevant comments in uaccess code. This also reflects
the might_sleep() checks in might_fault().

Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-4-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-19 08:39:14 +02:00
Borislav Petkov
b41e6ec242 x86/asm/uaccess: Get rid of copy_user_nocache_64.S
Move __copy_user_nocache() to arch/x86/lib/copy_user_64.S and
kill the containing file.

No functionality change.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431538944-27724-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-14 07:25:35 +02:00
Borislav Petkov
9e6b13f761 x86/asm/uaccess: Unify the ALIGN_DESTINATION macro
Pull it up into the header and kill duplicate versions.
Separately, both macros are identical:

 35948b2bd3431aee7149e85cfe4becbc  /tmp/a
 35948b2bd3431aee7149e85cfe4becbc  /tmp/b

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431538944-27724-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-14 07:25:34 +02:00
Borislav Petkov
26e7d9dee8 x86/asm/uaccess: Remove FIX_ALIGNMENT define from copy_user_nocache_64.S:
No code changed:

  # arch/x86/lib/copy_user_nocache_64.o:

   text    data     bss     dec     hex filename
    390       0       0     390     186 copy_user_nocache_64.o.before
    390       0       0     390     186 copy_user_nocache_64.o.after

md5:
   7fa0577b28700af89d3a67a8b590426e  copy_user_nocache_64.o.before.asm
   7fa0577b28700af89d3a67a8b590426e  copy_user_nocache_64.o.after.asm

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431538944-27724-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-14 07:25:34 +02:00
Linus Torvalds
d869844bd0 x86: fix special __probe_kernel_write() tail zeroing case
Commit cae2a173fe ("x86: clean up/fix 'copy_in_user()' tail zeroing")
fixed the failure case tail zeroing of one special case of the x86-64
generic user-copy routine, namely when used for the user-to-user case
("copy_in_user()").

But in the process it broke an even more unusual case: using the user
copy routine for kernel-to-kernel copying.

Now, normally kernel-kernel copies are obviously done using memcpy(),
but we have a couple of special cases when we use the user-copy
functions.  One is when we pass a kernel buffer to a regular user-buffer
routine, using set_fs(KERNEL_DS).  That's a "normal" case, and continued
to work fine, because it never takes any faults (with the possible
exception of a silent and successful vmalloc fault).

But Jan Beulich pointed out another, very unusual, special case: when we
use the user-copy routines not because it's a path that expects a user
pointer, but for a couple of ftrace/kgdb cases that want to do a kernel
copy, but do so using "unsafe" buffers, and use the user-copy routine to
gracefully handle faults.  IOW, for probe_kernel_write().

And that broke for the case of a faulting kernel destination, because we
saw the kernel destination and wanted to try to clear the tail of the
buffer.  Which doesn't work, since that's what faults.

This only triggers for things like kgdb and ftrace users (eg trying
setting a breakpoint on read-only memory), but it's definitely a bug.
The fix is to not compare against the kernel address start (TASK_SIZE),
but instead use the same limits "access_ok()" uses.

Reported-and-tested-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org # 4.0
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-24 06:58:27 -07:00
Linus Torvalds
60f898eeaa Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm changes from Ingo Molnar:
 "There were lots of changes in this development cycle:

   - over 100 separate cleanups, restructuring changes, speedups and
     fixes in the x86 system call, irq, trap and other entry code, part
     of a heroic effort to deobfuscate a decade old spaghetti asm code
     and its C code dependencies (Denys Vlasenko, Andy Lutomirski)

   - alternatives code fixes and enhancements (Borislav Petkov)

   - simplifications and cleanups to the compat code (Brian Gerst)

   - signal handling fixes and new x86 testcases (Andy Lutomirski)

   - various other fixes and cleanups

  By their nature many of these changes are risky - we tried to test
  them well on many different x86 systems (there are no known
  regressions), and they are split up finely to help bisection - but
  there's still a fair bit of residual risk left so caveat emptor"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (148 commits)
  perf/x86/64: Report regs_user->ax too in get_regs_user()
  perf/x86/64: Simplify regs_user->abi setting code in get_regs_user()
  perf/x86/64: Do report user_regs->cx while we are in syscall, in get_regs_user()
  perf/x86/64: Do not guess user_regs->cs, ss, sp in get_regs_user()
  x86/asm/entry/32: Tidy up JNZ instructions after TESTs
  x86/asm/entry/64: Reduce padding in execve stubs
  x86/asm/entry/64: Remove GET_THREAD_INFO() in ret_from_fork
  x86/asm/entry/64: Simplify jumps in ret_from_fork
  x86/asm/entry/64: Remove a redundant jump
  x86/asm/entry/64: Optimize [v]fork/clone stubs
  x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too
  x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat()
  x86/asm/entry/64: Use common code for rt_sigreturn() epilogue
  x86/asm/entry/64: Add forgotten CFI annotation
  x86/asm/entry/irq: Simplify interrupt dispatch table (IDT) layout
  x86/asm/entry/64: Move opportunistic sysret code to syscall code path
  x86, selftests: Add sigreturn selftest
  x86/alternatives: Guard NOPs optimization
  x86/asm/entry: Clear EXTRA_REGS for all executable formats
  x86/signal: Remove pax argument from restore_sigcontext
  ...
2015-04-13 13:16:36 -07:00
Linus Torvalds
cae2a173fe x86: clean up/fix 'copy_in_user()' tail zeroing
The rule for 'copy_from_user()' is that it zeroes the remaining kernel
buffer even when the copy fails halfway, just to make sure that we don't
leave uninitialized kernel memory around.  Because even if we check for
errors, some kernel buffers stay around after thge copy (think page
cache).

However, the x86-64 logic for user copies uses a copy_user_generic()
function for all the cases, that set the "zerorest" flag for any fault
on the source buffer.  Which meant that it didn't just try to clear the
kernel buffer after a failure in copy_from_user(), it also tried to
clear the destination user buffer for the "copy_in_user()" case.

Not only is that pointless, it also means that the clearing code has to
worry about the tail clearing taking page faults for the user buffer
case.  Which is just stupid, since that case shouldn't happen in the
first place.

Get rid of the whole "zerorest" thing entirely, and instead just check
if the destination is in kernel space or not.  And then just use
memset() to clear the tail of the kernel buffer if necessary.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-08 14:28:45 -07:00