While zeroing the upper 32 bits of an 8-byte getuser on 32-bit x86 was
fixed by commit 8c860ed825 ("x86/uaccess: Fix missed zeroing of ia32 u64
get_user() range checking") it was broken again in commit 8a2462df15
("x86/uaccess: Improve the 8-byte getuser() case").
This is because the register which holds the upper 32 bits (%ecx) is being
cleared _after_ the check_range, so if the range check fails, %ecx is never
cleared.
This can be reproduced with:
./tools/testing/kunit/kunit.py run --arch i386 usercopy
Instead, clear %ecx _before_ check_range in the 8-byte case. This
reintroduces a bit of the ugliness we were trying to avoid by adding
another #ifndef CONFIG_X86_64, but at least keeps check_range from needing
a separate bad_get_user_8 jump.
Fixes: 8a2462df15 ("x86/uaccess: Improve the 8-byte getuser() case")
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/all/20240731073031.4045579-1-davidgow@google.com
Commit in Fixes was added as a catch-all for cases where the cmdline is
parsed before being merged with the builtin one.
And promptly one issue appeared, see Link below. The microcode loader
really needs to parse it that early, but the merging happens later.
Reshuffling the early boot nightmare^W code to handle that properly would
be a painful exercise for another day so do the chicken thing and parse the
builtin cmdline too before it has been merged.
Fixes: 0c40b1c7a8 ("x86/setup: Warn when option parsing is done too early")
Reported-by: Mike Lothian <mike@fireburn.co.uk>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240730152108.GAZqkE5Dfi9AuKllRw@fat_crate.local
Link: https://lore.kernel.org/r/20240722152330.GCZp55ck8E_FT4kPnC@fat_crate.local
As described in commit:
e73c4e34a0 ("locking/atomic/x86: Introduce arch_atomic64_read_nonatomic() to x86_32")
the value preload before the CMPXCHG loop does not need to be atomic.
Introduce the read64_nonatomic assembly macro to load the value from a
atomic_t location in a faster non-atomic way and use it in
atomic64_cx8_32.S.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240605181424.3228-1-ubizjak@gmail.com
they're the only ones who can interpret the results properly
- The usual cleanups and fixes, left and right
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Merge tag 'x86_misc_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 updates from Borislav Petkov:
- Make error checking of AMD SMN accesses more robust in the callers as
they're the only ones who can interpret the results properly
- The usual cleanups and fixes, left and right
* tag 'x86_misc_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kmsan: Fix hook for unaligned accesses
x86/platform/iosf_mbi: Convert PCIBIOS_* return codes to errnos
x86/pci/xen: Fix PCIBIOS_* return code handling
x86/pci/intel_mid_pci: Fix PCIBIOS_* return code handling
x86/of: Return consistent error type from x86_of_pci_irq_enable()
hwmon: (k10temp) Rename _data variable
hwmon: (k10temp) Remove unused HAVE_TDIE() macro
hwmon: (k10temp) Reduce k10temp_get_ccd_support() parameters
hwmon: (k10temp) Define a helper function to read CCD temperature
x86/amd_nb: Enhance SMN access error checking
hwmon: (k10temp) Check return value of amd_smn_read()
EDAC/amd64: Check return value of amd_smn_read()
EDAC/amd64: Remove unused register accesses
tools/x86/kcpuid: Add missing dir via Makefile
x86, arm: Add missing license tag to syscall tables files
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Merge tag 'x86_core_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 uaccess update from Borislav Petkov:
- Cleanup the 8-byte getuser() asm case
* tag 'x86_core_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/uaccess: Improve the 8-byte getuser() case
string has been built and thus arguments can get lost
- Code cleanups and simplifications
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Merge tag 'x86_boot_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Borislav Petkov:
- Add a check to warn when cmdline parsing happens before the final
cmdline string has been built and thus arguments can get lost
- Code cleanups and simplifications
* tag 'x86_boot_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/setup: Warn when option parsing is done too early
x86/boot: Clean up the arch/x86/boot/main.c code a bit
x86/boot: Use current_stack_pointer to avoid asm() in init_heap()
When called with a 'from' that is not 4-byte-aligned, string_memcpy_fromio()
calls the movs() macro to copy the first few bytes, so that 'from' becomes
4-byte-aligned before calling rep_movs(). This movs() macro modifies 'to', and
the subsequent line modifies 'n'.
As a result, on unaligned accesses, kmsan_unpoison_memory() uses the updated
(aligned) values of 'to' and 'n'. Hence, it does not unpoison the entire
region.
Save the original values of 'to' and 'n', and pass those to
kmsan_unpoison_memory(), so that the entire region is unpoisoned.
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/r/20240523215029.4160518-1-bjohannesmeyer@gmail.com
When reworking the range checking for get_user(), the get_user_8() case
on 32-bit wasn't zeroing the high register. (The jump to bad_get_user_8
was accidentally dropped.) Restore the correct error handling
destination (and rename the jump to using the expected ".L" prefix).
While here, switch to using a named argument ("size") for the call
template ("%c4" to "%c[size]") as already used in the other call
templates in this file.
Found after moving the usercopy selftests to KUnit:
# usercopy_test_invalid: EXPECTATION FAILED at
lib/usercopy_kunit.c:278
Expected val_u64 == 0, but
val_u64 == -60129542144 (0xfffffff200000000)
Closes: https://lore.kernel.org/all/CABVgOSn=tb=Lj9SxHuT4_9MTjjKVxsq-ikdXC4kGHO4CfKVmGQ@mail.gmail.com
Fixes: b19b74bc99 ("x86/mm: Rework address range check in get_user() and put_user()")
Reported-by: David Gow <davidgow@google.com>
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Tested-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/all/20240610210213.work.143-kees%40kernel.org
Commit
4faa0e5d6d ("x86/boot: Move kernel cmdline setup earlier in the boot process (again)")
fixed and issue where cmdline parsing would happen before the final
boot_command_line string has been built from the builtin and boot
cmdlines and thus cmdline arguments would get lost.
Add a check to catch any future wrong use ordering so that such issues
can be caught in time.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240409152541.GCZhVd9XIPXyTNd9vc@fat_crate.local
Notable series include:
- Some maintenance and performance work for ocfs2 in Heming Zhao's
series "improve write IO performance when fragmentation is high".
- Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
exposed by fstests".
- kfifo header rework from Andy Shevchenko in the series "kfifo: Clean
up kfifo.h".
- GDB script fixes from Florian Rommel in the series "scripts/gdb: Fixes
for $lx_current and $lx_per_cpu".
- After much discussion, a coding-style update from Barry Song
explaining one reason why inline functions are preferred over macros.
The series is "codingstyle: avoid unused parameters for a function-like
macro".
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Merge tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-mm updates from Andrew Morton:
"Mainly singleton patches, documented in their respective changelogs.
Notable series include:
- Some maintenance and performance work for ocfs2 in Heming Zhao's
series "improve write IO performance when fragmentation is high".
- Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
exposed by fstests".
- kfifo header rework from Andy Shevchenko in the series "kfifo:
Clean up kfifo.h".
- GDB script fixes from Florian Rommel in the series "scripts/gdb:
Fixes for $lx_current and $lx_per_cpu".
- After much discussion, a coding-style update from Barry Song
explaining one reason why inline functions are preferred over
macros. The series is "codingstyle: avoid unused parameters for a
function-like macro""
* tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (62 commits)
fs/proc: fix softlockup in __read_vmcore
nilfs2: convert BUG_ON() in nilfs_finish_roll_forward() to WARN_ON()
scripts: checkpatch: check unused parameters for function-like macro
Documentation: coding-style: ask function-like macros to evaluate parameters
nilfs2: use __field_struct() for a bitwise field
selftests/kcmp: remove unused open mode
nilfs2: remove calls to folio_set_error() and folio_clear_error()
kernel/watchdog_perf.c: tidy up kerneldoc
watchdog: allow nmi watchdog to use raw perf event
watchdog: handle comma separated nmi_watchdog command line
nilfs2: make superblock data array index computation sparse friendly
squashfs: remove calls to set the folio error flag
squashfs: convert squashfs_symlink_read_folio to use folio APIs
scripts/gdb: fix detection of current CPU in KGDB
scripts/gdb: make get_thread_info accept pointers
scripts/gdb: fix parameter handling in $lx_per_cpu
scripts/gdb: fix failing KGDB detection during probe
kfifo: don't use "proxy" headers
media: stih-cec: add missing io.h
media: rc: add missing io.h
...
- Extend the x86 instruction decoder with APX and
other new instructions
- Misc cleanups
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2024-05-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf event updates from Ingo Molnar:
- Extend the x86 instruction decoder with APX and
other new instructions
- Misc cleanups
* tag 'perf-urgent-2024-05-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/cstate: Remove unused 'struct perf_cstate_msr'
perf/x86/rapl: Rename 'maxdie' to nr_rapl_pmu and 'dieid' to rapl_pmu_idx
x86/insn: Add support for APX EVEX instructions to the opcode map
x86/insn: Add support for APX EVEX to the instruction decoder logic
x86/insn: x86/insn: Add support for REX2 prefix to the instruction decoder opcode map
x86/insn: Add support for REX2 prefix to the instruction decoder logic
x86/insn: Add misc new Intel instructions
x86/insn: Add VEX versions of VPDPBUSD, VPDPBUSDS, VPDPWSSD and VPDPWSSDS
x86/insn: Fix PUSH instruction in x86 instruction decoder opcode map
x86/insn: Add Key Locker instructions to the opcode map
Normal set of driver updates and small fixes:
- Small improvements and fixes for erdma, efa, hfi1, bnxt_re
- Fix a UAF crash after module unload on leaking restrack entry
- Continue adding full RDMA support in mana with support for EQs, GID's
and CQs
- Improvements to the mkey cache in mlx5
- DSCP traffic class support in hns and several bug fixes
- Cap the maximum number of MADs in the receive queue to avoid OOM
- Another batch of rxe bug fixes from large scale testing
- __iowrite64_copy() optimizations for write combining MMIO memory
- Remove NULL checks before dev_put/hold()
- EFA support for receive with immediate
- Fix a recent memleaking regression in a cma error path
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull rdma updates from Jason Gunthorpe:
"Aside from the usual things this has an arch update for
__iowrite64_copy() used by the RDMA drivers.
This API was intended to generate large 64 byte MemWr TLPs on PCI.
These days most processors had done this by just repeating writel() in
a loop. S390 and some new ARM64 designs require a special helper to
get this to generate.
- Small improvements and fixes for erdma, efa, hfi1, bnxt_re
- Fix a UAF crash after module unload on leaking restrack entry
- Continue adding full RDMA support in mana with support for EQs,
GID's and CQs
- Improvements to the mkey cache in mlx5
- DSCP traffic class support in hns and several bug fixes
- Cap the maximum number of MADs in the receive queue to avoid OOM
- Another batch of rxe bug fixes from large scale testing
- __iowrite64_copy() optimizations for write combining MMIO memory
- Remove NULL checks before dev_put/hold()
- EFA support for receive with immediate
- Fix a recent memleaking regression in a cma error path"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (70 commits)
RDMA/cma: Fix kmemleak in rdma_core observed during blktests nvme/rdma use siw
RDMA/IPoIB: Fix format truncation compilation errors
bnxt_re: avoid shift undefined behavior in bnxt_qplib_alloc_init_hwq
RDMA/efa: Support QP with unsolicited write w/ imm. receive
IB/hfi1: Remove generic .ndo_get_stats64
IB/hfi1: Do not use custom stat allocator
RDMA/hfi1: Use RMW accessors for changing LNKCTL2
RDMA/mana_ib: implement uapi for creation of rnic cq
RDMA/mana_ib: boundary check before installing cq callbacks
RDMA/mana_ib: introduce a helper to remove cq callbacks
RDMA/mana_ib: create and destroy RNIC cqs
RDMA/mana_ib: create EQs for RNIC CQs
RDMA/core: Remove NULL check before dev_{put, hold}
RDMA/ipoib: Remove NULL check before dev_{put, hold}
RDMA/mlx5: Remove NULL check before dev_{put, hold}
RDMA/mlx5: Track DCT, DCI and REG_UMR QPs as diver_detail resources.
RDMA/core: Add an option to display driver-specific QPs in the rdmatool
RDMA/efa: Add shutdown notifier
RDMA/mana_ib: Fix missing ret value
IB/mlx5: Use __iowrite64_copy() for write combining stores
...
To support APX functionality, the EVEX prefix is used to:
- promote legacy instructions
- promote VEX instructions
- add new instructions
Promoted VEX instructions require no extra annotation because the opcodes
do not change and the permissive nature of the instruction decoder already
allows them to have an EVEX prefix.
Promoted legacy instructions and new instructions are placed in map 4 which
has not been used before.
Create a new table for map 4 and add APX instructions.
Annotate SCALABLE instructions with "(es)" - refer to patch "x86/insn: Add
support for APX EVEX to the instruction decoder logic". SCALABLE
instructions must be represented in both no-prefix (NP) and 66 prefix
forms.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-9-adrian.hunter@intel.com
Intel Advanced Performance Extensions (APX) extends the EVEX prefix to
support:
- extended general purpose registers (EGPRs) i.e. r16 to r31
- Push-Pop Acceleration (PPX) hints
- new data destination (NDD) register
- suppress status flags writes (NF) of common instructions
- new instructions
Refer to the Intel Advanced Performance Extensions (Intel APX) Architecture
Specification for details.
The extended EVEX prefix does not need amended instruction decoder logic,
except in one area. Some instructions are defined as SCALABLE which means
the EVEX.W bit and EVEX.pp bits are used to determine operand size.
Specifically, if an instruction is SCALABLE and EVEX.W is zero, then
EVEX.pp value 0 (representing no prefix NP) means default operand size,
whereas EVEX.pp value 1 (representing 66 prefix) means operand size
override i.e. 16 bits
Add an attribute (INAT_EVEX_SCALABLE) to identify such instructions, and
amend the logic appropriately.
Amend the awk script that generates the attribute tables from the opcode
map, to recognise "(es)" as attribute INAT_EVEX_SCALABLE.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-8-adrian.hunter@intel.com
Support for REX2 has been added to the instruction decoder logic and the
awk script that generates the attribute tables from the opcode map.
Add REX2 prefix byte (0xD5) to the opcode map.
Add annotation (!REX2) for map 0/1 opcodes that are reserved under REX2.
Add JMPABS to the opcode map and add annotation (REX2) to identify that it
has a mandatory REX2 prefix. A separate opcode attribute table is not
needed at this time because JMPABS has the same attribute encoding as the
MOV instruction that it shares an opcode with i.e. INAT_MOFFSET.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-7-adrian.hunter@intel.com
Intel Advanced Performance Extensions (APX) uses a new 2-byte prefix named
REX2 to select extended general purpose registers (EGPRs) i.e. r16 to r31.
The REX2 prefix is effectively an extended version of the REX prefix.
REX2 and EVEX are also used with PUSH/POP instructions to provide a
Push-Pop Acceleration (PPX) hint. With PPX hints, a CPU will attempt to
fast-forward register data between matching PUSH and POP instructions.
REX2 is valid only with opcodes in maps 0 and 1. Similar extension for
other maps is provided by the EVEX prefix, covered in a separate patch.
Some opcodes in maps 0 and 1 are reserved under REX2. One of these is used
for a new 64-bit absolute direct jump instruction JMPABS.
Refer to the Intel Advanced Performance Extensions (Intel APX) Architecture
Specification for details.
Define a code value for the REX2 prefix (INAT_PFX_REX2), and add attribute
flags for opcodes reserved under REX2 (INAT_NO_REX2) and to identify
opcodes (only JMPABS) that require a mandatory REX2 prefix
(INAT_REX2_VARIANT).
Amend logic to read the REX2 prefix and get the opcode attribute for the
map number (0 or 1) encoded in the REX2 prefix.
Amend the awk script that generates the attribute tables from the opcode
map, to recognise "REX2" as attribute INAT_PFX_REX2, and "(!REX2)"
as attribute INAT_NO_REX2, and "(REX2)" as attribute INAT_REX2_VARIANT.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-6-adrian.hunter@intel.com
The x86 instruction decoder is used not only for decoding kernel
instructions. It is also used by perf uprobes (user space probes) and by
perf tools Intel Processor Trace decoding. Consequently, it needs to
support instructions executed by user space also.
Add instructions documented in Intel Architecture Instruction Set
Extensions and Future Features Programming Reference March 2024
319433-052, that have not been added yet:
AADD
AAND
AOR
AXOR
CMPccXADD
PBNDKB
RDMSRLIST
URDMSR
UWRMSR
VBCSTNEBF162PS
VBCSTNESH2PS
VCVTNEEBF162PS
VCVTNEEPH2PS
VCVTNEOBF162PS
VCVTNEOPH2PS
VCVTNEPS2BF16
VPDPB[SU,UU,SS]D[,S]
VPDPW[SU,US,UU]D[,S]
VPMADD52HUQ
VPMADD52LUQ
VSHA512MSG1
VSHA512MSG2
VSHA512RNDS2
VSM3MSG1
VSM3MSG2
VSM3RNDS2
VSM4KEY4
VSM4RNDS4
WRMSRLIST
TCMMIMFP16PS
TCMMRLFP16PS
TDPFP16PS
PREFETCHIT1
PREFETCHIT0
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-5-adrian.hunter@intel.com
The x86 instruction decoder is used not only for decoding kernel
instructions. It is also used by perf uprobes (user space probes) and by
perf tools Intel Processor Trace decoding. Consequently, it needs to
support instructions executed by user space also.
Intel Architecture Instruction Set Extensions and Future Features manual
number 319433-044 of May 2021, documented VEX versions of instructions
VPDPBUSD, VPDPBUSDS, VPDPWSSD and VPDPWSSDS, but the opcode map has them
listed as EVEX only.
Remove EVEX-only (ev) annotation from instructions VPDPBUSD, VPDPBUSDS,
VPDPWSSD and VPDPWSSDS, which allows them to be decoded with either a VEX
or EVEX prefix.
Fixes: 0153d98f2d ("x86/insn: Add misc instructions to x86 instruction decoder")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-4-adrian.hunter@intel.com
The x86 instruction decoder is used not only for decoding kernel
instructions. It is also used by perf uprobes (user space probes) and by
perf tools Intel Processor Trace decoding. Consequently, it needs to
support instructions executed by user space also.
Opcode 0x68 PUSH instruction is currently defined as 64-bit operand size
only i.e. (d64). That was based on Intel SDM Opcode Map. However that is
contradicted by the Instruction Set Reference section for PUSH in the
same manual.
Remove 64-bit operand size only annotation from opcode 0x68 PUSH
instruction.
Example:
$ cat pushw.s
.global _start
.text
_start:
pushw $0x1234
mov $0x1,%eax # system call number (sys_exit)
int $0x80
$ as -o pushw.o pushw.s
$ ld -s -o pushw pushw.o
$ objdump -d pushw | tail -4
0000000000401000 <.text>:
401000: 66 68 34 12 pushw $0x1234
401004: b8 01 00 00 00 mov $0x1,%eax
401009: cd 80 int $0x80
$ perf record -e intel_pt//u ./pushw
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data ]
Before:
$ perf script --insn-trace=disasm
Warning:
1 instruction trace errors
pushw 10349 [000] 10586.869237014: 401000 [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) pushw $0x1234
pushw 10349 [000] 10586.869237014: 401006 [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) addb %al, (%rax)
pushw 10349 [000] 10586.869237014: 401008 [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) addb %cl, %ch
pushw 10349 [000] 10586.869237014: 40100a [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) addb $0x2e, (%rax)
instruction trace error type 1 time 10586.869237224 cpu 0 pid 10349 tid 10349 ip 0x40100d code 6: Trace doesn't match instruction
After:
$ perf script --insn-trace=disasm
pushw 10349 [000] 10586.869237014: 401000 [unknown] (./pushw) pushw $0x1234
pushw 10349 [000] 10586.869237014: 401004 [unknown] (./pushw) movl $1, %eax
Fixes: eb13296cfa ("x86: Instruction decoder API")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-3-adrian.hunter@intel.com
The x86 instruction decoder needs to know these new instructions that
are going to be used in the crypto library as well as the x86 core
code. Add the following:
LOADIWKEY:
Load a CPU-internal wrapping key.
ENCODEKEY128:
Wrap a 128-bit AES key to a key handle.
ENCODEKEY256:
Wrap a 256-bit AES key to a key handle.
AESENC128KL:
Encrypt a 128-bit block of data using a 128-bit AES key
indicated by a key handle.
AESENC256KL:
Encrypt a 128-bit block of data using a 256-bit AES key
indicated by a key handle.
AESDEC128KL:
Decrypt a 128-bit block of data using a 128-bit AES key
indicated by a key handle.
AESDEC256KL:
Decrypt a 128-bit block of data using a 256-bit AES key
indicated by a key handle.
AESENCWIDE128KL:
Encrypt 8 128-bit blocks of data using a 128-bit AES key
indicated by a key handle.
AESENCWIDE256KL:
Encrypt 8 128-bit blocks of data using a 256-bit AES key
indicated by a key handle.
AESDECWIDE128KL:
Decrypt 8 128-bit blocks of data using a 128-bit AES key
indicated by a key handle.
AESDECWIDE256KL:
Decrypt 8 128-bit blocks of data using a 256-bit AES key
indicated by a key handle.
The detail can be found in Intel Software Developer Manual.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20240502105853.5338-2-adrian.hunter@intel.com
Memory accesses in copy_mc_to_kernel() and copy_mc_to_user() are performed
by assembly routines and are invisible to KASAN, KCSAN, and KMSAN. Add
hooks from instrumentation.h to tell the tools these functions have
memcpy/copy_from_user semantics.
The call to copy_mc_fragile() in copy_mc_fragile_handle_tail() is left
intact, because the latter is only called from the assembly implementation
of copy_mc_fragile(), so the memory accesses in it are covered by the
instrumentation in copy_mc_to_kernel() and copy_mc_to_user().
Link: https://lore.kernel.org/all/3b7dbd88-0861-4638-b2d2-911c97a4cadf@I-love.SAKURA.ne.jp/
Link: https://lkml.kernel.org/r/20240320101851.2589698-3-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Start switching iomap_copy routines over to use #define and arch provided
inline/macro functions instead of weak symbols.
Inline functions allow more compiler optimization and this is often a
driver hot path.
x86 has the only weak implementation for __iowrite32_copy(), so replace it
with a static inline containing the same single instruction inline
assembly. The compiler will generate the "mov edx,ecx" in a more optimal
way.
Remove iomap_copy_64.S
Link: https://lore.kernel.org/r/1-v3-1893cd8b9369+1925-mlx5_arm_wc_jgg@nvidia.com
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The using-default-thunk warning check makes sense only with
configurations which actually enable the special return thunks.
Otherwise, it fires on unrelated 32-bit configs on which the special
return thunks won't even work (they're 64-bit only) and, what is more,
those configs even go off into the weeds when booting in the
alternatives patching code, leading to a dead machine.
Fixes: 4461438a84 ("x86/retpoline: Ensure default return thunk isn't used at runtime")
Reported-by: Klara Modin <klarasmodin@gmail.com>
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Klara Modin <klarasmodin@gmail.com>
Link: https://lore.kernel.org/r/78e0d19c-b77a-4169-a80f-2eef91f4a1d6@gmail.com
Link: https://lore.kernel.org/r/20240413024956.488d474e@yea
srso_alias_untrain_ret() is special code, even if it is a dummy
which is called in the !SRSO case, so annotate it like its real
counterpart, to address the following objtool splat:
vmlinux.o: warning: objtool: .export_symbol+0x2b290: data relocation to !ENDBR: srso_alias_untrain_ret+0x0
Fixes: 4535e1a417 ("x86/bugs: Fix the SRSO mitigation on Zen3/4")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240405144637.17908-1-bp@kernel.org
The srso_alias_untrain_ret() dummy thunk in the !CONFIG_MITIGATION_SRSO
case is there only for the altenative in CALL_UNTRAIN_RET to have
a symbol to resolve.
However, testing with kernels which don't have CONFIG_MITIGATION_SRSO
enabled, leads to the warning in patch_return() to fire:
missing return thunk: srso_alias_untrain_ret+0x0/0x10-0x0: eb 0e 66 66 2e
WARNING: CPU: 0 PID: 0 at arch/x86/kernel/alternative.c:826 apply_returns (arch/x86/kernel/alternative.c:826
Put in a plain "ret" there so that gcc doesn't put a return thunk in
in its place which special and gets checked.
In addition:
ERROR: modpost: "srso_alias_untrain_ret" [arch/x86/kvm/kvm-amd.ko] undefined!
make[2]: *** [scripts/Makefile.modpost:145: Module.symvers] Chyba 1
make[1]: *** [/usr/src/linux-6.8.3/Makefile:1873: modpost] Chyba 2
make: *** [Makefile:240: __sub-make] Chyba 2
since !SRSO builds would use the dummy return thunk as reported by
petr.pisar@atlas.cz, https://bugzilla.kernel.org/show_bug.cgi?id=218679.
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202404020901.da75a60f-oliver.sang@intel.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/all/202404020901.da75a60f-oliver.sang@intel.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The original version of the mitigation would patch in the calls to the
untraining routines directly. That is, the alternative() in UNTRAIN_RET
will patch in the CALL to srso_alias_untrain_ret() directly.
However, even if commit e7c25c441e ("x86/cpu: Cleanup the untrain
mess") meant well in trying to clean up the situation, due to micro-
architectural reasons, the untraining routine srso_alias_untrain_ret()
must be the target of a CALL instruction and not of a JMP instruction as
it is done now.
Reshuffle the alternative macros to accomplish that.
Fixes: e7c25c441e ("x86/cpu: Cleanup the untrain mess")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a new conflict with Linus's upstream tree, because
in the following merge conflict resolution in <asm/coco.h>:
38b334fc76 Merge tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Linus has resolved the conflicting placement of 'cc_mask' better
than the original commit:
1c811d403a x86/sev: Fix position dependent variable references in startup code
... which was also done by an internal merge resolution:
2e5fc4786b Merge branch 'x86/sev' into x86/boot, to resolve conflicts and to pick up dependent tree
But Linus is right in 38b334fc76, the 'cc_mask' declaration is sufficient
within the #ifdef CONFIG_ARCH_HAS_CC_PLATFORM block.
So instead of forcing Linus to do the same resolution again, merge in Linus's
tree and follow his conflict resolution.
Conflicts:
arch/x86/include/asm/coco.h
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- The biggest change is the rework of the percpu code,
to support the 'Named Address Spaces' GCC feature,
by Uros Bizjak:
- This allows C code to access GS and FS segment relative
memory via variables declared with such attributes,
which allows the compiler to better optimize those accesses
than the previous inline assembly code.
- The series also includes a number of micro-optimizations
for various percpu access methods, plus a number of
cleanups of %gs accesses in assembly code.
- These changes have been exposed to linux-next testing for
the last ~5 months, with no known regressions in this area.
- Fix/clean up __switch_to()'s broken but accidentally
working handling of FPU switching - which also generates
better code.
- Propagate more RIP-relative addressing in assembly code,
to generate slightly better code.
- Rework the CPU mitigations Kconfig space to be less idiosyncratic,
to make it easier for distros to follow & maintain these options.
- Rework the x86 idle code to cure RCU violations and
to clean up the logic.
- Clean up the vDSO Makefile logic.
- Misc cleanups and fixes.
[ Please note that there's a higher number of merge commits in
this branch (three) than is usual in x86 topic trees. This happened
due to the long testing lifecycle of the percpu changes that
involved 3 merge windows, which generated a longer history
and various interactions with other core x86 changes that we
felt better about to carry in a single branch. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core x86 updates from Ingo Molnar:
- The biggest change is the rework of the percpu code, to support the
'Named Address Spaces' GCC feature, by Uros Bizjak:
- This allows C code to access GS and FS segment relative memory
via variables declared with such attributes, which allows the
compiler to better optimize those accesses than the previous
inline assembly code.
- The series also includes a number of micro-optimizations for
various percpu access methods, plus a number of cleanups of %gs
accesses in assembly code.
- These changes have been exposed to linux-next testing for the
last ~5 months, with no known regressions in this area.
- Fix/clean up __switch_to()'s broken but accidentally working handling
of FPU switching - which also generates better code
- Propagate more RIP-relative addressing in assembly code, to generate
slightly better code
- Rework the CPU mitigations Kconfig space to be less idiosyncratic, to
make it easier for distros to follow & maintain these options
- Rework the x86 idle code to cure RCU violations and to clean up the
logic
- Clean up the vDSO Makefile logic
- Misc cleanups and fixes
* tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
x86/idle: Select idle routine only once
x86/idle: Let prefer_mwait_c1_over_halt() return bool
x86/idle: Cleanup idle_setup()
x86/idle: Clean up idle selection
x86/idle: Sanitize X86_BUG_AMD_E400 handling
sched/idle: Conditionally handle tick broadcast in default_idle_call()
x86: Increase brk randomness entropy for 64-bit systems
x86/vdso: Move vDSO to mmap region
x86/vdso/kbuild: Group non-standard build attributes and primary object file rules together
x86/vdso: Fix rethunk patching for vdso-image-{32,64}.o
x86/retpoline: Ensure default return thunk isn't used at runtime
x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32
x86/vdso: Use $(addprefix ) instead of $(foreach )
x86/vdso: Simplify obj-y addition
x86/vdso: Consolidate targets and clean-files
x86/bugs: Rename CONFIG_RETHUNK => CONFIG_MITIGATION_RETHUNK
x86/bugs: Rename CONFIG_CPU_SRSO => CONFIG_MITIGATION_SRSO
x86/bugs: Rename CONFIG_CPU_IBRS_ENTRY => CONFIG_MITIGATION_IBRS_ENTRY
x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY => CONFIG_MITIGATION_UNRET_ENTRY
x86/bugs: Rename CONFIG_SLS => CONFIG_MITIGATION_SLS
...
cure Sparse warnings.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-cleanups-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Ingo Molnar:
"Misc cleanups, including a large series from Thomas Gleixner to cure
sparse warnings"
* tag 'x86-cleanups-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/nmi: Drop unused declaration of proc_nmi_enabled()
x86/callthunks: Use EXPORT_PER_CPU_SYMBOL_GPL() for per CPU variables
x86/cpu: Provide a declaration for itlb_multihit_kvm_mitigation
x86/cpu: Use EXPORT_PER_CPU_SYMBOL_GPL() for x86_spec_ctrl_current
x86/uaccess: Add missing __force to casts in __access_ok() and valid_user_address()
x86/percpu: Cure per CPU madness on UP
smp: Consolidate smp_prepare_boot_cpu()
x86/msr: Add missing __percpu annotations
x86/msr: Prepare for including <linux/percpu.h> into <asm/msr.h>
perf/x86/amd/uncore: Fix __percpu annotation
x86/nmi: Remove an unnecessary IS_ENABLED(CONFIG_SMP)
x86/apm_32: Remove dead function apm_get_battery_status()
x86/insn-eval: Fix function param name in get_eff_addr_sib()
FRED is a replacement for IDT event delivery on x86 and addresses most of
the technical nightmares which IDT exposes:
1) Exception cause registers like CR2 need to be manually preserved in
nested exception scenarios.
2) Hardware interrupt stack switching is suboptimal for nested exceptions
as the interrupt stack mechanism rewinds the stack on each entry which
requires a massive effort in the low level entry of #NMI code to handle
this.
3) No hardware distinction between entry from kernel or from user which
makes establishing kernel context more complex than it needs to be
especially for unconditionally nestable exceptions like NMI.
4) NMI nesting caused by IRET unconditionally reenabling NMIs, which is a
problem when the perf NMI takes a fault when collecting a stack trace.
5) Partial restore of ESP when returning to a 16-bit segment
6) Limitation of the vector space which can cause vector exhaustion on
large systems.
7) Inability to differentiate NMI sources
FRED addresses these shortcomings by:
1) An extended exception stack frame which the CPU uses to save exception
cause registers. This ensures that the meta information for each
exception is preserved on stack and avoids the extra complexity of
preserving it in software.
2) Hardware interrupt stack switching is non-rewinding if a nested
exception uses the currently interrupt stack.
3) The entry points for kernel and user context are separate and GS BASE
handling which is required to establish kernel context for per CPU
variable access is done in hardware.
4) NMIs are now nesting protected. They are only reenabled on the return
from NMI.
5) FRED guarantees full restore of ESP
6) FRED does not put a limitation on the vector space by design because it
uses a central entry points for kernel and user space and the CPUstores
the entry type (exception, trap, interrupt, syscall) on the entry stack
along with the vector number. The entry code has to demultiplex this
information, but this removes the vector space restriction.
The first hardware implementations will still have the current
restricted vector space because lifting this limitation requires
further changes to the local APIC.
7) FRED stores the vector number and meta information on stack which
allows having more than one NMI vector in future hardware when the
required local APIC changes are in place.
The series implements the initial FRED support by:
- Reworking the existing entry and IDT handling infrastructure to
accomodate for the alternative entry mechanism.
- Expanding the stack frame to accomodate for the extra 16 bytes FRED
requires to store context and meta information
- Providing FRED specific C entry points for events which have information
pushed to the extended stack frame, e.g. #PF and #DB.
- Providing FRED specific C entry points for #NMI and #MCE
- Implementing the FRED specific ASM entry points and the C code to
demultiplex the events
- Providing detection and initialization mechanisms and the necessary
tweaks in context switching, GS BASE handling etc.
The FRED integration aims for maximum code reuse vs. the existing IDT
implementation to the extent possible and the deviation in hot paths like
context switching are handled with alternatives to minimalize the
impact. The low level entry and exit paths are seperate due to the extended
stack frame and the hardware based GS BASE swichting and therefore have no
impact on IDT based systems.
It has been extensively tested on existing systems and on the FRED
simulation and as of now there are know outstanding problems.
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Merge tag 'x86-fred-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 FRED support from Thomas Gleixner:
"Support for x86 Fast Return and Event Delivery (FRED).
FRED is a replacement for IDT event delivery on x86 and addresses most
of the technical nightmares which IDT exposes:
1) Exception cause registers like CR2 need to be manually preserved
in nested exception scenarios.
2) Hardware interrupt stack switching is suboptimal for nested
exceptions as the interrupt stack mechanism rewinds the stack on
each entry which requires a massive effort in the low level entry
of #NMI code to handle this.
3) No hardware distinction between entry from kernel or from user
which makes establishing kernel context more complex than it needs
to be especially for unconditionally nestable exceptions like NMI.
4) NMI nesting caused by IRET unconditionally reenabling NMIs, which
is a problem when the perf NMI takes a fault when collecting a
stack trace.
5) Partial restore of ESP when returning to a 16-bit segment
6) Limitation of the vector space which can cause vector exhaustion
on large systems.
7) Inability to differentiate NMI sources
FRED addresses these shortcomings by:
1) An extended exception stack frame which the CPU uses to save
exception cause registers. This ensures that the meta information
for each exception is preserved on stack and avoids the extra
complexity of preserving it in software.
2) Hardware interrupt stack switching is non-rewinding if a nested
exception uses the currently interrupt stack.
3) The entry points for kernel and user context are separate and GS
BASE handling which is required to establish kernel context for
per CPU variable access is done in hardware.
4) NMIs are now nesting protected. They are only reenabled on the
return from NMI.
5) FRED guarantees full restore of ESP
6) FRED does not put a limitation on the vector space by design
because it uses a central entry points for kernel and user space
and the CPUstores the entry type (exception, trap, interrupt,
syscall) on the entry stack along with the vector number. The
entry code has to demultiplex this information, but this removes
the vector space restriction.
The first hardware implementations will still have the current
restricted vector space because lifting this limitation requires
further changes to the local APIC.
7) FRED stores the vector number and meta information on stack which
allows having more than one NMI vector in future hardware when the
required local APIC changes are in place.
The series implements the initial FRED support by:
- Reworking the existing entry and IDT handling infrastructure to
accomodate for the alternative entry mechanism.
- Expanding the stack frame to accomodate for the extra 16 bytes FRED
requires to store context and meta information
- Providing FRED specific C entry points for events which have
information pushed to the extended stack frame, e.g. #PF and #DB.
- Providing FRED specific C entry points for #NMI and #MCE
- Implementing the FRED specific ASM entry points and the C code to
demultiplex the events
- Providing detection and initialization mechanisms and the necessary
tweaks in context switching, GS BASE handling etc.
The FRED integration aims for maximum code reuse vs the existing IDT
implementation to the extent possible and the deviation in hot paths
like context switching are handled with alternatives to minimalize the
impact. The low level entry and exit paths are seperate due to the
extended stack frame and the hardware based GS BASE swichting and
therefore have no impact on IDT based systems.
It has been extensively tested on existing systems and on the FRED
simulation and as of now there are no outstanding problems"
* tag 'x86-fred-2024-03-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
x86/fred: Fix init_task thread stack pointer initialization
MAINTAINERS: Add a maintainer entry for FRED
x86/fred: Fix a build warning with allmodconfig due to 'inline' failing to inline properly
x86/fred: Invoke FRED initialization code to enable FRED
x86/fred: Add FRED initialization functions
x86/syscall: Split IDT syscall setup code into idt_syscall_init()
KVM: VMX: Call fred_entry_from_kvm() for IRQ/NMI handling
x86/entry: Add fred_entry_from_kvm() for VMX to handle IRQ/NMI
x86/entry/calling: Allow PUSH_AND_CLEAR_REGS being used beyond actual entry code
x86/fred: Fixup fault on ERETU by jumping to fred_entrypoint_user
x86/fred: Let ret_from_fork_asm() jmp to asm_fred_exit_user when FRED is enabled
x86/traps: Add sysvec_install() to install a system interrupt handler
x86/fred: FRED entry/exit and dispatch code
x86/fred: Add a machine check entry stub for FRED
x86/fred: Add a NMI entry stub for FRED
x86/fred: Add a debug fault entry stub for FRED
x86/idtentry: Incorporate definitions/declarations of the FRED entries
x86/fred: Make exc_page_fault() work for FRED
x86/fred: Allow single-step trap and NMI when starting a new task
x86/fred: No ESPFIX needed when FRED is enabled
...
The early SME/SEV code parses the command line very early, in order to
decide whether or not memory encryption should be enabled, which needs
to occur even before the initial page tables are created.
This is problematic for a number of reasons:
- this early code runs from the 1:1 mapping provided by the decompressor
or firmware, which uses a different translation than the one assumed by
the linker, and so the code needs to be built in a special way;
- parsing external input while the entire kernel image is still mapped
writable is a bad idea in general, and really does not belong in
security minded code;
- the current code ignores the built-in command line entirely (although
this appears to be the case for the entire decompressor)
Given that the decompressor/EFI stub is an intrinsic part of the x86
bootable kernel image, move the command line parsing there and out of
the core kernel. This removes the need to build lib/cmdline.o in a
special way, or to use RIP-relative LEA instructions in inline asm
blocks.
This involves a new xloadflag in the setup header to indicate
that mem_encrypt=on appeared on the kernel command line.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20240227151907.387873-17-ardb+git@google.com
Sparse rightfully complains about using a plain pointer for per CPU
accessors:
msr-smp.c:15:23: sparse: warning: incorrect type in initializer (different address spaces)
msr-smp.c:15:23: sparse: expected void const [noderef] __percpu *__vpp_verify
msr-smp.c:15:23: sparse: got struct msr *
Add __percpu annotations to the related datastructure and function
arguments to cure this. This also cures the related sparse warnings at the
callsites in drivers/edac/amd64_edac.c.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240304005104.513181735@linutronix.de
No point in checking again as this was already done by the caller.
Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240222111636.2214523-3-nik.borisov@suse.com
It's pointless checking if a particular part of an instruction is
decoded before calling the routine responsible for decoding it as this
check is duplicated in the routines itself. Streamline the code by
removing the superfluous checks. No functional difference.
Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240222111636.2214523-2-nik.borisov@suse.com
Change "regoff" to "base_offset" in 2 places in the kernel-doc comments to
prevent warnings:
insn-eval.c:1152: warning: Function parameter or member 'base_offset' not described in 'get_eff_addr_sib'
insn-eval.c:1152: warning: Excess function parameter 'regoff' description in 'get_eff_addr_sib'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240211062452.16411-1-rdunlap@infradead.org
Make sure the default return thunk is not used after all return
instructions have been patched by the alternatives because the default
return thunk is insufficient when it comes to mitigating Retbleed or
SRSO.
Fix based on an earlier version by David Kaplan <david.kaplan@amd.com>.
[ bp: Fix the compilation error of warn_thunk_thunk being an invisible
symbol, hoist thunk macro into calling.h ]
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Co-developed-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231010171020.462211-4-david.kaplan@amd.com
Link: https://lore.kernel.org/r/20240104132446.GEZZaxnrIgIyat0pqf@fat_crate.local
ERETU returns from an event handler while making a transition to ring 3,
and ERETS returns from an event handler while staying in ring 0.
Add instruction opcodes used by ERET[US] to the x86 opcode map; opcode
numbers are per FRED spec v5.0.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20231205105030.8698-10-xin3.li@intel.com
During memory error injection test on kernels >= v6.4, the kernel panics
like below. However, this issue couldn't be reproduced on kernels <= v6.3.
mce: [Hardware Error]: CPU 296: Machine Check Exception: f Bank 1: bd80000000100134
mce: [Hardware Error]: RIP 10:<ffffffff821b9776> {__get_user_nocheck_4+0x6/0x20}
mce: [Hardware Error]: TSC 411a93533ed ADDR 346a8730040 MISC 86
mce: [Hardware Error]: PROCESSOR 0:a06d0 TIME 1706000767 SOCKET 1 APIC 211 microcode 80001490
mce: [Hardware Error]: Run the above through 'mcelog --ascii'
mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel
Kernel panic - not syncing: Fatal local machine check
The MCA code can recover from an in-kernel #MC if the fixup type is
EX_TYPE_UACCESS, explicitly indicating that the kernel is attempting to
access userspace memory. However, if the fixup type is EX_TYPE_DEFAULT
the only thing that is raised for an in-kernel #MC is a panic.
ex_handler_uaccess() would warn if users gave a non-canonical addresses
(with bit 63 clear) to {get, put}_user(), which was unexpected.
Therefore, commit
b19b74bc99 ("x86/mm: Rework address range check in get_user() and put_user()")
replaced _ASM_EXTABLE_UA() with _ASM_EXTABLE() for {get, put}_user()
fixups. However, the new fixup type EX_TYPE_DEFAULT results in a panic.
Commit
6014bc2756 ("x86-64: make access_ok() independent of LAM")
added the check gp_fault_address_ok() right before the WARN_ONCE() in
ex_handler_uaccess() to not warn about non-canonical user addresses due
to LAM.
With that in place, revert back to _ASM_EXTABLE_UA() for {get,put}_user()
exception fixups in order to be able to handle in-kernel MCEs correctly
again.
[ bp: Massage commit message. ]
Fixes: b19b74bc99 ("x86/mm: Rework address range check in get_user() and put_user()")
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/20240129063842.61584-1-qiuxu.zhuo@intel.com
WRMSRNS is an instruction that behaves exactly like WRMSR, with
the only difference being that it is not a serializing instruction
by default. Under certain conditions, WRMSRNS may replace WRMSR to
improve performance.
Add its CPU feature bit, opcode to the x86 opcode map, and an
always inline API __wrmsrns() to embed WRMSRNS into the code.
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231205105030.8698-2-xin3.li@intel.com
The goal is to get sched.h down to a type only header, so the main thing
happening in this patchset is splitting out various _types.h headers and
dependency fixups, as well as moving some things out of sched.h to
better locations.
This is prep work for the memory allocation profiling patchset which
adds new sched.h interdepencencies.
Testing - it's been in -next, and fixes from pretty much all
architectures have percolated in - nothing major.
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Merge tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs
Pull header cleanups from Kent Overstreet:
"The goal is to get sched.h down to a type only header, so the main
thing happening in this patchset is splitting out various _types.h
headers and dependency fixups, as well as moving some things out of
sched.h to better locations.
This is prep work for the memory allocation profiling patchset which
adds new sched.h interdepencencies"
* tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits)
Kill sched.h dependency on rcupdate.h
kill unnecessary thread_info.h include
Kill unnecessary kernel.h include
preempt.h: Kill dependency on list.h
rseq: Split out rseq.h from sched.h
LoongArch: signal.c: add header file to fix build error
restart_block: Trim includes
lockdep: move held_lock to lockdep_types.h
sem: Split out sem_types.h
uidgid: Split out uidgid_types.h
seccomp: Split out seccomp_types.h
refcount: Split out refcount_types.h
uapi/linux/resource.h: fix include
x86/signal: kill dependency on time.h
syscall_user_dispatch.h: split out *_types.h
mm_types_task.h: Trim dependencies
Split out irqflags_types.h
ipc: Kill bogus dependency on spinlock.h
shm: Slim down dependencies
workqueue: Split out workqueue_types.h
...
Step 5/10 of the namespace unification of CPU mitigations related Kconfig options.
[ mingo: Converted a few more uses in comments/messages as well. ]
Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ariel Miculas <amiculas@cisco.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231121160740.1249350-6-leitao@debian.org
