commit 6613d82e61 upstream.
The VERW mitigation at exit-to-user is enabled via a static branch
mds_user_clear. This static branch is never toggled after boot, and can
be safely replaced with an ALTERNATIVE() which is convenient to use in
asm.
Switch to ALTERNATIVE() to use the VERW mitigation late in exit-to-user
path. Also remove the now redundant VERW in exc_nmi() and
arch_exit_to_user_mode().
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20240213-delay-verw-v8-4-a6216d83edb7%40linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
another set of traditional Chinese translations.
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Merge tag 'docs-5.15-2' of git://git.lwn.net/linux
Pull more documentation updates from Jonathan Corbet:
"Another collection of documentation patches, mostly fixes but also
includes another set of traditional Chinese translations"
* tag 'docs-5.15-2' of git://git.lwn.net/linux:
docs: pdfdocs: Fix typo in CJK-language specific font settings
docs: kernel-hacking: Remove inappropriate text
docs/zh_TW: add translations for zh_TW/filesystems
docs/zh_TW: add translations for zh_TW/cpu-freq
docs/zh_TW: add translations for zh_TW/arm64
docs/zh_CN: Modify the translator tag and fix the wrong word
Documentation/features/vm: correct huge-vmap APIs
Documentation: block: blk-mq: Fix small typo in multi-queue docs
Documentation: in_irq() cleanup
Documentation: arm: marvell: Add 88F6825 model into list
Documentation/process/maintainer-pgp-guide: Replace broken link to PGP path finder
Documentation: locking: fix references
Documentation: Update details of The Linux Kernel Module Programming Guide
docs: x86: Remove obsolete information about x86_64 vmalloc() faulting
Documentation/process/applying-patches: Activate linux-next man hyperlink
x86_64 vmalloc() mappings are no longer "synchronized" among page tables
via faulting since commit 6eb82f9940 ("x86/mm: Pre-allocate P4D/PUD
pages for vmalloc area"), since the corresponding P4D or PUD pages are
now preallocated at boot, by preallocate_vmalloc_pages(). Drop the
"lazily synchronized" description for less confusion.
While this file is x86_64-specific, it is worth noting that things are
different for x86_32, where vmalloc()-related changes to `init_mm.pgd` are
synchronized to all page tables in the system during runtime, via
arch_sync_kernel_mappings(). Unfortunately, this synchronization is
subject to race condition, which is further handled via faulting, see
vmalloc_fault(). See commit 4819e15f74 ("x86/mm/32: Bring back vmalloc
faulting on x86_32") for more details.
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20210818220123.2623-1-yepeilin.cs@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
commit 5955633e91 ("x86/reboot: Skip DMI checks if reboot set by user")
made it so that it's not required to recompile the kernel in order to
bypass broken reboot quirks compiled into an image:
* This variable is used privately to keep track of whether or not
* reboot_type is still set to its default value (i.e., reboot= hasn't
* been set on the command line). This is needed so that we can
* suppress DMI scanning for reboot quirks. Without it, it's
* impossible to override a faulty reboot quirk without recompiling.
However, at the time it was not eally documented outside the source code,
and so this information isn't really available to the average user out
there.
The change is a little white lie and invented "reboot=default" since it is
easy to remember, and documents well. The truth is that any random string
that is *not* a currently accepted string will work.
Since that doesn't document well for non-coders, and since it's unknown
what the future additions might be, lay claim on "default" since that is
exactly what it achieves.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210530162447.996461-3-paul.gortmaker@windriver.com
- Prevent sigaltstack out of bounds writes. The kernel unconditionally
writes the FPU state to the alternate stack without checking whether
the stack is large enough to accomodate it.
Check the alternate stack size before doing so and in case it's too
small force a SIGSEGV instead of silently corrupting user space data.
- MINSIGSTKZ and SIGSTKSZ are constants in signal.h and have never been
updated despite the fact that the FPU state which is stored on the
signal stack has grown over time which causes trouble in the field
when AVX512 is available on a CPU. The kernel does not expose the
minimum requirements for the alternate stack size depending on the
available and enabled CPU features.
ARM already added an aux vector AT_MINSIGSTKSZ for the same reason.
Add it to x86 as well
- A major cleanup of the x86 FPU code. The recent discoveries of XSTATE
related issues unearthed quite some inconsistencies, duplicated code
and other issues.
The fine granular overhaul addresses this, makes the code more robust
and maintainable, which allows to integrate upcoming XSTATE related
features in sane ways.
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Merge tag 'x86-fpu-2021-07-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fpu updates from Thomas Gleixner:
"Fixes and improvements for FPU handling on x86:
- Prevent sigaltstack out of bounds writes.
The kernel unconditionally writes the FPU state to the alternate
stack without checking whether the stack is large enough to
accomodate it.
Check the alternate stack size before doing so and in case it's too
small force a SIGSEGV instead of silently corrupting user space
data.
- MINSIGSTKZ and SIGSTKSZ are constants in signal.h and have never
been updated despite the fact that the FPU state which is stored on
the signal stack has grown over time which causes trouble in the
field when AVX512 is available on a CPU. The kernel does not expose
the minimum requirements for the alternate stack size depending on
the available and enabled CPU features.
ARM already added an aux vector AT_MINSIGSTKSZ for the same reason.
Add it to x86 as well.
- A major cleanup of the x86 FPU code. The recent discoveries of
XSTATE related issues unearthed quite some inconsistencies,
duplicated code and other issues.
The fine granular overhaul addresses this, makes the code more
robust and maintainable, which allows to integrate upcoming XSTATE
related features in sane ways"
* tag 'x86-fpu-2021-07-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits)
x86/fpu/xstate: Clear xstate header in copy_xstate_to_uabi_buf() again
x86/fpu/signal: Let xrstor handle the features to init
x86/fpu/signal: Handle #PF in the direct restore path
x86/fpu: Return proper error codes from user access functions
x86/fpu/signal: Split out the direct restore code
x86/fpu/signal: Sanitize copy_user_to_fpregs_zeroing()
x86/fpu/signal: Sanitize the xstate check on sigframe
x86/fpu/signal: Remove the legacy alignment check
x86/fpu/signal: Move initial checks into fpu__restore_sig()
x86/fpu: Mark init_fpstate __ro_after_init
x86/pkru: Remove xstate fiddling from write_pkru()
x86/fpu: Don't store PKRU in xstate in fpu_reset_fpstate()
x86/fpu: Remove PKRU handling from switch_fpu_finish()
x86/fpu: Mask PKRU from kernel XRSTOR[S] operations
x86/fpu: Hook up PKRU into ptrace()
x86/fpu: Add PKRU storage outside of task XSAVE buffer
x86/fpu: Dont restore PKRU in fpregs_restore_userspace()
x86/fpu: Rename xfeatures_mask_user() to xfeatures_mask_uabi()
x86/fpu: Move FXSAVE_LEAK quirk info __copy_kernel_to_fpregs()
x86/fpu: Rename __fpregs_load_activate() to fpregs_restore_userregs()
...
- Some kernel-doc cleanups. That script is still regex onslaught from
hell, but it has gotten a little better.
- Improvements to the checkpatch docs, which are also used by the tool
itself.
- A major update to the pathname lookup documentation.
- Elimination of :doc: markup, since our automarkup magic can create
references from filenames without all the extra noise.
- The flurry of Chinese translation activity continues.
Plus, of course, the usual collection of updates, typo fixes, and warning
fixes.
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Merge tag 'docs-5.14' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"This was a reasonably active cycle for documentation; this includes:
- Some kernel-doc cleanups. That script is still regex onslaught from
hell, but it has gotten a little better.
- Improvements to the checkpatch docs, which are also used by the
tool itself.
- A major update to the pathname lookup documentation.
- Elimination of :doc: markup, since our automarkup magic can create
references from filenames without all the extra noise.
- The flurry of Chinese translation activity continues.
Plus, of course, the usual collection of updates, typo fixes, and
warning fixes"
* tag 'docs-5.14' of git://git.lwn.net/linux: (115 commits)
docs: path-lookup: use bare function() rather than literals
docs: path-lookup: update symlink description
docs: path-lookup: update get_link() ->follow_link description
docs: path-lookup: update WALK_GET, WALK_PUT desc
docs: path-lookup: no get_link()
docs: path-lookup: update i_op->put_link and cookie description
docs: path-lookup: i_op->follow_link replaced with i_op->get_link
docs: path-lookup: Add macro name to symlink limit description
docs: path-lookup: remove filename_mountpoint
docs: path-lookup: update do_last() part
docs: path-lookup: update path_mountpoint() part
docs: path-lookup: update path_to_nameidata() part
docs: path-lookup: update follow_managed() part
docs: Makefile: Use CONFIG_SHELL not SHELL
docs: Take a little noise out of the build process
docs: x86: avoid using ReST :doc:`foo` markup
docs: virt: kvm: s390-pv-boot.rst: avoid using ReST :doc:`foo` markup
docs: userspace-api: landlock.rst: avoid using ReST :doc:`foo` markup
docs: trace: ftrace.rst: avoid using ReST :doc:`foo` markup
docs: trace: coresight: coresight.rst: avoid using ReST :doc:`foo` markup
...
- Add the "ratelimit:N" parameter to the split_lock_detect= boot option,
to rate-limit the generation of bus-lock exceptions. This is both
easier on system resources and kinder to offending applications than
the current policy of outright killing them.
- Document the split-lock detection feature and its parameters.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-splitlock-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 splitlock updates from Ingo Molnar:
- Add the "ratelimit:N" parameter to the split_lock_detect= boot
option, to rate-limit the generation of bus-lock exceptions.
This is both easier on system resources and kinder to offending
applications than the current policy of outright killing them.
- Document the split-lock detection feature and its parameters.
* tag 'x86-splitlock-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Documentation/x86: Add ratelimit in buslock.rst
Documentation/admin-guide: Add bus lock ratelimit
x86/bus_lock: Set rate limit for bus lock
Documentation/x86: Add buslock.rst
Historically, signal.h defines MINSIGSTKSZ (2KB) and SIGSTKSZ (8KB), for
use by all architectures with sigaltstack(2). Over time, the hardware state
size grew, but these constants did not evolve. Today, literal use of these
constants on several architectures may result in signal stack overflow, and
thus user data corruption.
A few years ago, the ARM team addressed this issue by establishing
getauxval(AT_MINSIGSTKSZ). This enables the kernel to supply a value
at runtime that is an appropriate replacement on current and future
hardware.
Add getauxval(AT_MINSIGSTKSZ) support to x86, analogous to the support
added for ARM in
94b07c1f8c ("arm64: signal: Report signal frame size to userspace via auxv").
Also, include a documentation to describe x86-specific auxiliary vectors.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Len Brown <len.brown@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20210518200320.17239-4-chang.seok.bae@intel.com
ratelimit is a new command line option for bus lock handling. Add proper
documentation.
[ tglx: Massaged documentation ]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210419214958.4035512-5-fenghua.yu@intel.com
Add buslock.rst to explain bus lock problem and how to detect and
handle it.
[ tglx: Included it into index.rst and added the missing include ... ]
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20210419214958.4035512-2-fenghua.yu@intel.com
The SYSCFG MSR continued being updated beyond the K8 family; drop the K8
name from it.
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20210427111636.1207-4-brijesh.singh@amd.com
kernel-doc fix, some regression-reporting updates, and the usual minor
fixes.
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Merge tag 'docs-5.13-2' of git://git.lwn.net/linux
Pull documentation fixes from Jonathan Corbet:
"A few late-arriving documentation fixes, including some oprofile
cleanup, a kernel-doc fix, some regression-reporting updates, and the
usual minor fixes"
* tag 'docs-5.13-2' of git://git.lwn.net/linux:
Enlisted oprofile version line removed
oprofiled version output line removed from the list
Removed the oprofiled version option
docs: reporting-issues.rst: CC subsystem and maintainers on regressions
docs: correct URL to bios and kernel developer's guide
docs/core-api: Consistent code style
docs/zh_CN: Adjust order and content of zh_CN/index.rst
Documentation: input: joydev file corrections
docs: Fix typo in Documentation/x86/x86_64/5level-paging.rst
kernel-doc: Add support for __deprecated
fix two typos in the documentation
(Documentation/x86/x86_64/5level-paging.rst), changing 'paing' for 'paging'
and using the right verbal form for plural on 'some vendors offer'.
Signed-off-by: Carlos Bilbao <bilbao@vt.edu>
Link: https://lore.kernel.org/r/2599991.mvXUDI8C0e@iron-maiden
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Add a misc device /dev/sgx_vepc to allow userspace to allocate "raw"
Enclave Page Cache (EPC) without an associated enclave. The intended
and only known use case for raw EPC allocation is to expose EPC to a
KVM guest, hence the 'vepc' moniker, virt.{c,h} files and X86_SGX_KVM
Kconfig.
The SGX driver uses the misc device /dev/sgx_enclave to support
userspace in creating an enclave. Each file descriptor returned from
opening /dev/sgx_enclave represents an enclave. Unlike the SGX driver,
KVM doesn't control how the guest uses the EPC, therefore EPC allocated
to a KVM guest is not associated with an enclave, and /dev/sgx_enclave
is not suitable for allocating EPC for a KVM guest.
Having separate device nodes for the SGX driver and KVM virtual EPC also
allows separate permission control for running host SGX enclaves and KVM
SGX guests.
To use /dev/sgx_vepc to allocate a virtual EPC instance with particular
size, the hypervisor opens /dev/sgx_vepc, and uses mmap() with the
intended size to get an address range of virtual EPC. Then it may use
the address range to create one KVM memory slot as virtual EPC for
a guest.
Implement the "raw" EPC allocation in the x86 core-SGX subsystem via
/dev/sgx_vepc rather than in KVM. Doing so has two major advantages:
- Does not require changes to KVM's uAPI, e.g. EPC gets handled as
just another memory backend for guests.
- EPC management is wholly contained in the SGX subsystem, e.g. SGX
does not have to export any symbols, changes to reclaim flows don't
need to be routed through KVM, SGX's dirty laundry doesn't have to
get aired out for the world to see, and so on and so forth.
The virtual EPC pages allocated to guests are currently not reclaimable.
Reclaiming an EPC page used by enclave requires a special reclaim
mechanism separate from normal page reclaim, and that mechanism is not
supported for virutal EPC pages. Due to the complications of handling
reclaim conflicts between guest and host, reclaiming virtual EPC pages
is significantly more complex than basic support for SGX virtualization.
[ bp:
- Massage commit message and comments
- use cpu_feature_enabled()
- vertically align struct members init
- massage Virtual EPC clarification text
- move Kconfig prompt to Virtualization ]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/0c38ced8c8e5a69872db4d6a1c0dabd01e07cad7.1616136308.git.kai.huang@intel.com
EREMOVE takes a page and removes any association between that page and
an enclave. It must be run on a page before it can be added into another
enclave. Currently, EREMOVE is run as part of pages being freed into the
SGX page allocator. It is not expected to fail, as it would indicate a
use-after-free of EPC pages. Rather than add the page back to the pool
of available EPC pages, the kernel intentionally leaks the page to avoid
additional errors in the future.
However, KVM does not track how guest pages are used, which means that
SGX virtualization use of EREMOVE might fail. Specifically, it is
legitimate that EREMOVE returns SGX_CHILD_PRESENT for EPC assigned to
KVM guest, because KVM/kernel doesn't track SECS pages.
To allow SGX/KVM to introduce a more permissive EREMOVE helper and
to let the SGX virtualization code use the allocator directly, break
out the EREMOVE call from the SGX page allocator. Rename the original
sgx_free_epc_page() to sgx_encl_free_epc_page(), indicating that
it is used to free an EPC page assigned to a host enclave. Replace
sgx_free_epc_page() with sgx_encl_free_epc_page() in all call sites so
there's no functional change.
At the same time, improve the error message when EREMOVE fails, and
add documentation to explain to the user what that failure means and
to suggest to the user what to do when this bug happens in the case it
happens.
[ bp: Massage commit message, fix typos and sanitize text, simplify. ]
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/20210325093057.122834-1-kai.huang@intel.com
struct setup_data.len is the length of data field. In case of
SETUP_INDIRECT, it should be sizeof(setup_indirect).
Signed-off-by: Cao jin <jojing64@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Link: https://lore.kernel.org/r/20210127084911.63438-1-jojing64@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
of the churn behind us. Significant stuff in this pull includes:
- A set of new Chinese translations
- Italian translation updates
- A mechanism from Mauro to automatically format Documentation/features
for the built docs
- Automatic cross references without explicit :ref: markup
- A new reset-controller document
- An extensive new document on reporting problems from Thorsten
That last patch also adds the CC-BY-4.0 license to LICENSES/dual; there was
some discussion on this, but we seem to have consensus and an ack from Greg
for that addition.
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Merge tag 'docs-5.11' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A much quieter cycle for documentation (happily), with, one hopes, the
bulk of the churn behind us. Significant stuff in this pull includes:
- A set of new Chinese translations
- Italian translation updates
- A mechanism from Mauro to automatically format
Documentation/features for the built docs
- Automatic cross references without explicit :ref: markup
- A new reset-controller document
- An extensive new document on reporting problems from Thorsten
That last patch also adds the CC-BY-4.0 license to LICENSES/dual;
there was some discussion on this, but we seem to have consensus and
an ack from Greg for that addition"
* tag 'docs-5.11' of git://git.lwn.net/linux: (50 commits)
docs: fix broken cross reference in translations/zh_CN
docs: Note that sphinx 1.7 will be required soon
docs: update requirements to install six module
docs: reporting-issues: move 'outdated, need help' note to proper place
docs: Update documentation to reflect what TAINT_CPU_OUT_OF_SPEC means
docs: add a reset controller chapter to the driver API docs
docs: make reporting-bugs.rst obsolete
docs: Add a new text describing how to report bugs
LICENSES: Add the CC-BY-4.0 license
Documentation: fix multiple typos found in the admin-guide subdirectory
Documentation: fix typos found in admin-guide subdirectory
kernel-doc: Fix example in Nested structs/unions
docs: clean up sysctl/kernel: titles, version
docs: trace: fix event state structure name
docs: nios2: add missing ReST file
scripts: get_feat.pl: reduce table width for all features output
scripts: get_feat.pl: change the group by order
scripts: get_feat.pl: make complete table more coincise
scripts: kernel-doc: fix parsing function-like typedefs
Documentation: fix typos found in process, dev-tools, and doc-guide subdirectories
...
(Fenghua Yu)
- Cleanups.
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Merge tag 'x86_cache_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cache resource control updates from Borislav Petkov:
- add logic to correct MBM total and local values fixing errata SKX99
and BDF102 (Fenghua Yu)
- cleanups
* tag 'x86_cache_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Clean up unused function parameter in rmdir path
x86/resctrl: Constify kernfs_ops
x86/resctrl: Correct MBM total and local values
Documentation/x86: Rename resctrl_ui.rst and add two errata to the file
code to use it (Yazen Ghannam)
- Remove a dead and unused TSEG region remapping workaround on AMD (Arvind Sankar)
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Merge tag 'x86_cpu_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpuid updates from Borislav Petkov:
"Only AMD-specific changes this time:
- Save the AMD physical die ID into cpuinfo_x86.cpu_die_id and
convert all code to use it (Yazen Ghannam)
- Remove a dead and unused TSEG region remapping workaround on AMD
(Arvind Sankar)"
* tag 'x86_cpu_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu/amd: Remove dead code for TSEG region remapping
x86/topology: Set cpu_die_id only if DIE_TYPE found
EDAC/mce_amd: Use struct cpuinfo_x86.cpu_die_id for AMD NodeId
x86/CPU/AMD: Remove amd_get_nb_id()
x86/CPU/AMD: Save AMD NodeId as cpu_die_id
AMD systems provide a "NodeId" value that represents a global ID
indicating to which "Node" a logical CPU belongs. The "Node" is a
physical structure equivalent to a Die, and it should not be confused
with logical structures like NUMA nodes. Logical nodes can be adjusted
based on firmware or other settings whereas the physical nodes/dies are
fixed based on hardware topology.
The NodeId value can be used when a physical ID is needed by software.
Save the AMD NodeId to struct cpuinfo_x86.cpu_die_id. Use the value
from CPUID or MSR as appropriate. Default to phys_proc_id otherwise.
Do so for both AMD and Hygon systems.
Drop the node_id parameter from cacheinfo_*_init_llc_id() as it is no
longer needed.
Update the x86 topology documentation.
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201109210659.754018-2-Yazen.Ghannam@amd.com
Document the Intel SGX kernel architecture. The fine-grained architecture
details can be looked up from Intel SDM Volume 3D.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Cc: linux-doc@vger.kernel.org
Link: https://lkml.kernel.org/r/20201112220135.165028-24-jarkko@kernel.org
Intel Memory Bandwidth Monitoring (MBM) counters may report system
memory bandwidth incorrectly on some Intel processors. This is reported
in documented in erratum SKX99, erratum BDF102 and in the RDT reference
manual, see Documentation/x86/index.rst.
To work around the errata, MBM total and local readings are corrected
using a correction factor table.
Since the correction factor table is not publicly documented anywhere,
document the table and the errata in Documentation/x86/resctrl.rst for
future reference.
[ bp: Move web links to the doc, massage. ]
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20201014004927.1839452-2-fenghua.yu@intel.com
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Merge tag 'docs-5.10-2' of git://git.lwn.net/linux
Pull documentation fixes from Jonathan Corbet:
"A handful of late-arriving documentation fixes"
* tag 'docs-5.10-2' of git://git.lwn.net/linux:
docs: Add two missing entries in vm sysctl index
docs/vm: trivial fixes to several spelling mistakes
docs: submitting-patches: describe preserving review/test tags
Documentation: Chinese translation of Documentation/arm64/hugetlbpage.rst
Documentation: x86: fix a missing word in x86_64/mm.rst.
docs: driver-api: remove a duplicated index entry
docs: lkdtm: Modernize and improve details
docs: deprecated.rst: Expand str*cpy() replacement notes
docs/cpu-load: format the example code.
- Update dtc to upstream version v1.6.0-31-gcbca977ea121
- dtx_diff help text reformatting
- Speed-up validation time for binding and dtb checks using json for
intermediate files
- Add support for running yamllint on DT schema files
- Remove old booting-without-of.rst
- Extend the example schema to address common issues
- Cleanup handling of additionalProperties/unevaluatedProperties
- Ensure all DSI controller schemas reference dsi-controller.yaml
- Vendor prefixes for Zealz, Wandbord/Technexion, Embest RIoT, Rex, DFI,
and Cisco Meraki
- Convert at25, SPMI bus, TI hwlock, HiSilicon Hi3660 USB3 PHY, Arm
SP805 watchdog, Arm SP804, and Samsung 11-pin USB connector to DT
schema
- Convert HiSilicon SoC and syscon bindings to DT schema
- Convert SiFive Risc-V L2 cache, PLIC, PRCI, and PWM to DT schema
- Convert i.MX bindings for w1, crypto, rng, SIM, PM, DDR,
SATA, vf610 GPIO, and UART to DT schema
- Add i.MX 8M compatible strings
- Add LM81 and DS1780 as trivial devices
- Various missing properties added to fix dtb validation warnings
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Merge tag 'devicetree-for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring:
- Update dtc to upstream version v1.6.0-31-gcbca977ea121
- dtx_diff help text reformatting
- Speed-up validation time for binding and dtb checks using json for
intermediate files
- Add support for running yamllint on DT schema files
- Remove old booting-without-of.rst
- Extend the example schema to address common issues
- Cleanup handling of additionalProperties/unevaluatedProperties
- Ensure all DSI controller schemas reference dsi-controller.yaml
- Vendor prefixes for Zealz, Wandbord/Technexion, Embest RIoT, Rex,
DFI, and Cisco Meraki
- Convert at25, SPMI bus, TI hwlock, HiSilicon Hi3660 USB3 PHY, Arm
SP805 watchdog, Arm SP804, and Samsung 11-pin USB connector to DT
schema
- Convert HiSilicon SoC and syscon bindings to DT schema
- Convert SiFive Risc-V L2 cache, PLIC, PRCI, and PWM to DT schema
- Convert i.MX bindings for w1, crypto, rng, SIM, PM, DDR, SATA, vf610
GPIO, and UART to DT schema
- Add i.MX 8M compatible strings
- Add LM81 and DS1780 as trivial devices
- Various missing properties added to fix dtb validation warnings
* tag 'devicetree-for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (111 commits)
dt-bindings: misc: explicitly add #address-cells for slave mode
spi: dt-bindings: spi-controller: explicitly require #address-cells=<0> for slave mode
dt: Remove booting-without-of.rst
dt-bindings: update usb-c-connector example
dt-bindings: arm: hisilicon: add missing properties into cpuctrl.yaml
dt-bindings: arm: hisilicon: add missing properties into sysctrl.yaml
dt-bindings: pwm: imx: document i.MX compatibles
scripts/dtc: Update to upstream version v1.6.0-31-gcbca977ea121
dt-bindings: Add running yamllint to dt_binding_check
dt-bindings: powerpc: Add a schema for the 'sleep' property
dt-bindings: pinctrl: sirf: Fix typo abitrary
dt-bindings: pinctrl: qcom: Fix typo abitrary
dt-bindings: Explicitly allow additional properties in common schemas
dt-bindings: Use 'additionalProperties' instead of 'unevaluatedProperties'
dt-bindings: Add missing 'unevaluatedProperties'
Docs: Fixing spelling errors in Documentation/devicetree/bindings/
dt-bindings: arm: hisilicon: convert Hi6220 domain controller bindings to json-schema
dt-bindings: riscv: convert pwm bindings to json-schema
dt-bindings: riscv: convert plic bindings to json-schema
dt-bindings: fu540: prci: convert PRCI bindings to json-schema
...
Disable parsing of the HMAT for debug, to workaround broken platform
instances, or cases where it is otherwise not wanted.
[rdunlap@infradead.org: fix build when CONFIG_ACPI is not set]
Link: https://lkml.kernel.org/r/70e5ee34-9809-a997-7b49-499e4be61307@infradead.org
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Brice Goglin <Brice.Goglin@inria.fr>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jia He <justin.he@arm.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Will Deacon <will@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Hulk Robot <hulkci@huawei.com>
Cc: Jason Yan <yanaijie@huawei.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Link: https://lkml.kernel.org/r/159643095540.4062302.732962081968036212.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
booting-without-of.rst is an ancient document that first outlined
Flattened DeviceTree on PowerPC initially. The DT world has evolved a
lot in the 15 years since and booting-without-of.rst is pretty stale.
The name of the document itself is confusing if you don't understand the
evolution from real 'OpenFirmware'. Most of what booting-without-of.rst
contains is now in the DT specification (which evolved out of the
ePAPR). The few things that weren't documented in the DT specification
are now.
All that remains is the boot entry details, so let's move these to arch
specific documents. The exception is arm which already has the same
details documented.
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-mips@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Rob Herring <robh@kernel.org>
James Morse.
* Add support for controlling per-thread memory bandwidth throttling
delay values on hw which supports it, by Fenghua Yu.
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Merge tag 'x86_cache_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cache resource control updates from Borislav Petkov:
- Misc cleanups to the resctrl code in preparation for the ARM side
(James Morse)
- Add support for controlling per-thread memory bandwidth throttling
delay values on hw which supports it (Fenghua Yu)
* tag 'x86_cache_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Enable user to view thread or core throttling mode
x86/resctrl: Enumerate per-thread MBA controls
cacheinfo: Move resctrl's get_cache_id() to the cacheinfo header file
x86/resctrl: Add struct rdt_cache::arch_has_{sparse, empty}_bitmaps
x86/resctrl: Merge AMD/Intel parse_bw() calls
x86/resctrl: Add struct rdt_membw::arch_needs_linear to explain AMD/Intel MBA difference
x86/resctrl: Use is_closid_match() in more places
x86/resctrl: Include pid.h
x86/resctrl: Use container_of() in delayed_work handlers
x86/resctrl: Fix stale comment
x86/resctrl: Remove struct rdt_membw::max_delay
x86/resctrl: Remove unused struct mbm_state::chunks_bw
don't spam the console log, by Chris Down.
* Document how the /proc/cpuinfo machinery works for future reference,
by Kyung Min Park, Ricardo Neri and Dave Hansen.
* Correct the current NMI's duration calculation, by Libing Zhou.
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Merge tag 'x86_misc_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 fixes fromm Borislav Petkov:
- Ratelimit the message about writes to unrecognized MSRs so that they
don't spam the console log (Chris Down)
- Document how the /proc/cpuinfo machinery works for future reference
(Kyung Min Park, Ricardo Neri and Dave Hansen)
- Correct the current NMI's duration calculation (Libing Zhou)
* tag 'x86_misc_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/nmi: Fix nmi_handle() duration miscalculation
Documentation/x86: Add documentation for /proc/cpuinfo feature flags
x86/msr: Make source of unrecognised MSR writes unambiguous
x86/msr: Prevent userspace MSR access from dominating the console
devices which doesn't need pinning of pages for DMA anymore. Add support
for the command submission to devices using new x86 instructions like
ENQCMD{,S} and MOVDIR64B. In addition, add support for process address
space identifiers (PASIDs) which are referenced by those command
submission instructions along with the handling of the PASID state on
context switch as another extended state. Work by Fenghua Yu, Ashok Raj,
Yu-cheng Yu and Dave Jiang.
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Merge tag 'x86_pasid_for_5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PASID updates from Borislav Petkov:
"Initial support for sharing virtual addresses between the CPU and
devices which doesn't need pinning of pages for DMA anymore.
Add support for the command submission to devices using new x86
instructions like ENQCMD{,S} and MOVDIR64B. In addition, add support
for process address space identifiers (PASIDs) which are referenced by
those command submission instructions along with the handling of the
PASID state on context switch as another extended state.
Work by Fenghua Yu, Ashok Raj, Yu-cheng Yu and Dave Jiang"
* tag 'x86_pasid_for_5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Add an enqcmds() wrapper for the ENQCMDS instruction
x86/asm: Carve out a generic movdir64b() helper for general usage
x86/mmu: Allocate/free a PASID
x86/cpufeatures: Mark ENQCMD as disabled when configured out
mm: Add a pasid member to struct mm_struct
x86/msr-index: Define an IA32_PASID MSR
x86/fpu/xstate: Add supervisor PASID state for ENQCMD
x86/cpufeatures: Enumerate ENQCMD and ENQCMDS instructions
Documentation/x86: Add documentation for SVA (Shared Virtual Addressing)
iommu/vt-d: Change flags type to unsigned int in binding mm
drm, iommu: Change type of pasid to u32
The file zero-page.txt does not exit. Add links to zero-page.rst
instead.
[ bp: Massage a bit. ]
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201002190623.7489-1-xypron.glpk@gmx.de
ENQCMD and Data Streaming Accelerator (DSA) and all of their associated
features are a complicated stack with lots of interconnected pieces.
This documentation provides a big picture overview for all of the
features.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1600187413-163670-4-git-send-email-fenghua.yu@intel.com
/proc/cpuinfo shows features which the kernel supports. Some of these
flags are derived from CPUID, and others are derived from other sources,
including some that are entirely software-based. Currently, there is
not any documentation in the kernel about how /proc/cpuinfo flags are
generated and what it means when they are missing.
Add documentation for /proc/cpuinfo feature flags enumeration.
Document how and when x86 feature flags are used. Also discuss what
their presence or absence mean for the kernel and users.
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Co-developed-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200831183500.15481-1-kyung.min.park@intel.com
Early Intel hardware implementations of Memory Bandwidth Allocation (MBA)
could only control bandwidth at the processor core level. This meant that
when two processes with different bandwidth allocations ran simultaneously
on the same core the hardware had to resolve this difference. It did so by
applying the higher throttling value (lower bandwidth) to both processes.
Newer implementations can apply different throttling values to each
thread on a core.
Introduce a new resctrl file, "thread_throttle_mode", on Intel systems
that shows to the user how throttling values are allocated, per-core or
per-thread.
On systems that support per-core throttling, the file will display "max".
On newer systems that support per-thread throttling, the file will display
"per-thread".
AMD confirmed in [1] that AMD bandwidth allocation is already at thread
level but that the AMD implementation does not use a memory delay
throttle mode. So to avoid confusion the thread throttling mode would be
UNDEFINED on AMD systems and the "thread_throttle_mode" file will not be
visible.
Originally-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/1598296281-127595-3-git-send-email-fenghua.yu@intel.com
Link: [1] https://lore.kernel.org/lkml/18d277fd-6523-319c-d560-66b63ff606b8@amd.com
while to come. Changes include:
- Some new Chinese translations
- Progress on the battle against double words words and non-HTTPS URLs
- Some block-mq documentation
- More RST conversions from Mauro. At this point, that task is
essentially complete, so we shouldn't see this kind of churn again for a
while. Unless we decide to switch to asciidoc or something...:)
- Lots of typo fixes, warning fixes, and more.
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Merge tag 'docs-5.9' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"It's been a busy cycle for documentation - hopefully the busiest for a
while to come. Changes include:
- Some new Chinese translations
- Progress on the battle against double words words and non-HTTPS
URLs
- Some block-mq documentation
- More RST conversions from Mauro. At this point, that task is
essentially complete, so we shouldn't see this kind of churn again
for a while. Unless we decide to switch to asciidoc or
something...:)
- Lots of typo fixes, warning fixes, and more"
* tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits)
scripts/kernel-doc: optionally treat warnings as errors
docs: ia64: correct typo
mailmap: add entry for <alobakin@marvell.com>
doc/zh_CN: add cpu-load Chinese version
Documentation/admin-guide: tainted-kernels: fix spelling mistake
MAINTAINERS: adjust kprobes.rst entry to new location
devices.txt: document rfkill allocation
PCI: correct flag name
docs: filesystems: vfs: correct flag name
docs: filesystems: vfs: correct sync_mode flag names
docs: path-lookup: markup fixes for emphasis
docs: path-lookup: more markup fixes
docs: path-lookup: fix HTML entity mojibake
CREDITS: Replace HTTP links with HTTPS ones
docs: process: Add an example for creating a fixes tag
doc/zh_CN: add Chinese translation prefer section
doc/zh_CN: add clearing-warn-once Chinese version
doc/zh_CN: add admin-guide index
doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label
futex: MAINTAINERS: Re-add selftests directory
...
this has been brought into a shape which is maintainable and actually
works.
This final version was done by Sasha Levin who took it up after Intel
dropped the ball. Sasha discovered that the SGX (sic!) offerings out there
ship rogue kernel modules enabling FSGSBASE behind the kernels back which
opens an instantanious unpriviledged root hole.
The FSGSBASE instructions provide a considerable speedup of the context
switch path and enable user space to write GSBASE without kernel
interaction. This enablement requires careful handling of the exception
entries which go through the paranoid entry path as they cannot longer rely
on the assumption that user GSBASE is positive (as enforced via prctl() on
non FSGSBASE enabled systemn). All other entries (syscalls, interrupts and
exceptions) can still just utilize SWAPGS unconditionally when the entry
comes from user space. Converting these entries to use FSGSBASE has no
benefit as SWAPGS is only marginally slower than WRGSBASE and locating and
retrieving the kernel GSBASE value is not a free operation either. The real
benefit of RD/WRGSBASE is the avoidance of the MSR reads and writes.
The changes come with appropriate selftests and have held up in field
testing against the (sanitized) Graphene-SGX driver.
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Merge tag 'x86-fsgsbase-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fsgsbase from Thomas Gleixner:
"Support for FSGSBASE. Almost 5 years after the first RFC to support
it, this has been brought into a shape which is maintainable and
actually works.
This final version was done by Sasha Levin who took it up after Intel
dropped the ball. Sasha discovered that the SGX (sic!) offerings out
there ship rogue kernel modules enabling FSGSBASE behind the kernels
back which opens an instantanious unpriviledged root hole.
The FSGSBASE instructions provide a considerable speedup of the
context switch path and enable user space to write GSBASE without
kernel interaction. This enablement requires careful handling of the
exception entries which go through the paranoid entry path as they
can no longer rely on the assumption that user GSBASE is positive (as
enforced via prctl() on non FSGSBASE enabled systemn).
All other entries (syscalls, interrupts and exceptions) can still just
utilize SWAPGS unconditionally when the entry comes from user space.
Converting these entries to use FSGSBASE has no benefit as SWAPGS is
only marginally slower than WRGSBASE and locating and retrieving the
kernel GSBASE value is not a free operation either. The real benefit
of RD/WRGSBASE is the avoidance of the MSR reads and writes.
The changes come with appropriate selftests and have held up in field
testing against the (sanitized) Graphene-SGX driver"
* tag 'x86-fsgsbase-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
x86/fsgsbase: Fix Xen PV support
x86/ptrace: Fix 32-bit PTRACE_SETREGS vs fsbase and gsbase
selftests/x86/fsgsbase: Add a missing memory constraint
selftests/x86/fsgsbase: Fix a comment in the ptrace_write_gsbase test
selftests/x86: Add a syscall_arg_fault_64 test for negative GSBASE
selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE
selftests/x86/fsgsbase: Test GS selector on ptracer-induced GS base write
Documentation/x86/64: Add documentation for GS/FS addressing mode
x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2
x86/cpu: Enable FSGSBASE on 64bit by default and add a chicken bit
x86/entry/64: Handle FSGSBASE enabled paranoid entry/exit
x86/entry/64: Introduce the FIND_PERCPU_BASE macro
x86/entry/64: Switch CR3 before SWAPGS in paranoid entry
x86/speculation/swapgs: Check FSGSBASE in enabling SWAPGS mitigation
x86/process/64: Use FSGSBASE instructions on thread copy and ptrace
x86/process/64: Use FSBSBASE in switch_to() if available
x86/process/64: Make save_fsgs_for_kvm() ready for FSGSBASE
x86/fsgsbase/64: Enable FSGSBASE instructions in helper functions
x86/fsgsbase/64: Add intrinsics for FSGSBASE instructions
x86/cpu: Add 'unsafe_fsgsbase' to enable CR4.FSGSBASE
...
- Add support for zstd compressed kernel
- Define __DISABLE_EXPORTS in Makefile
- Remove __DISABLE_EXPORTS definition from kaslr.c
- Bump the heap size for zstd.
- Update the documentation.
Integrates the ZSTD decompression code to the x86 pre-boot code.
Zstandard requires slightly more memory during the kernel decompression
on x86 (192 KB vs 64 KB), and the memory usage is independent of the
window size.
__DISABLE_EXPORTS is now defined in the Makefile, which covers both
the existing use in kaslr.c, and the use needed by the zstd decompressor
in misc.c.
This patch has been boot tested with both a zstd and gzip compressed
kernel on i386 and x86_64 using buildroot and QEMU.
Additionally, this has been tested in production on x86_64 devices.
We saw a 2 second boot time reduction by switching kernel compression
from xz to zstd.
Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200730190841.2071656-7-nickrterrell@gmail.com
Drop the doubled word "and".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20200703213107.30758-2-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Drop the doubled word "see".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20200703213107.30758-3-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Explain how the GS/FS based addressing can be utilized in user space
applications along with the differences between the generic prctl() based
GS/FS base control and the FSGSBASE version available on newer CPUs.
Originally-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200528201402.1708239-15-sashal@kernel.org
set from Mauro toward the completion of the RST conversion. I *really*
hope we are getting close to the end of this. Meanwhile, those patches
reach pretty far afield to update document references around the tree;
there should be no actual code changes there. There will be, alas, more of
the usual trivial merge conflicts.
Beyond that we have more translations, improvements to the sphinx
scripting, a number of additions to the sysctl documentation, and lots of
fixes.
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Merge tag 'docs-5.8' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A fair amount of stuff this time around, dominated by yet another
massive set from Mauro toward the completion of the RST conversion. I
*really* hope we are getting close to the end of this. Meanwhile,
those patches reach pretty far afield to update document references
around the tree; there should be no actual code changes there. There
will be, alas, more of the usual trivial merge conflicts.
Beyond that we have more translations, improvements to the sphinx
scripting, a number of additions to the sysctl documentation, and lots
of fixes"
* tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits)
Documentation: fixes to the maintainer-entry-profile template
zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst
tracing: Fix events.rst section numbering
docs: acpi: fix old http link and improve document format
docs: filesystems: add info about efivars content
Documentation: LSM: Correct the basic LSM description
mailmap: change email for Ricardo Ribalda
docs: sysctl/kernel: document unaligned controls
Documentation: admin-guide: update bug-hunting.rst
docs: sysctl/kernel: document ngroups_max
nvdimm: fixes to maintainter-entry-profile
Documentation/features: Correct RISC-V kprobes support entry
Documentation/features: Refresh the arch support status files
Revert "docs: sysctl/kernel: document ngroups_max"
docs: move locking-specific documents to locking/
docs: move digsig docs to the security book
docs: move the kref doc into the core-api book
docs: add IRQ documentation at the core-api book
docs: debugging-via-ohci1394.txt: add it to the core-api book
docs: fix references for ipmi.rst file
...
The EFI handover protocol was introduced on x86 to permit the boot
loader to pass a populated boot_params structure as an additional
function argument to the entry point. This allows the bootloader to
pass the base and size of a initrd image, which is more flexible
than relying on the EFI stub's file I/O routines, which can only
access the file system from which the kernel image itself was loaded
from firmware.
This approach requires a fair amount of internal knowledge regarding
the layout of the boot_params structure on the part of the boot loader,
as well as knowledge regarding the allowed placement of the initrd in
memory, and so it has been deprecated in favour of a new initrd loading
method that is based on existing UEFI protocols and best practices.
So update the x86 boot protocol documentation to clarify that the EFI
handover protocol has been deprecated, and while at it, add a note that
invoking the EFI handover protocol still requires the PE/COFF image to
be loaded properly (as opposed to simply being copied into memory).
Also, drop the code32_start header field from the list of values that
need to be provided, as this is no longer required.
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200409130434.6736-7-ardb@kernel.org
Pull x86 cleanups from Ingo Molnar:
"This topic tree contains more commits than usual:
- most of it are uaccess cleanups/reorganization by Al
- there's a bunch of prototype declaration (--Wmissing-prototypes)
cleanups
- misc other cleanups all around the map"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
x86/mm/set_memory: Fix -Wmissing-prototypes warnings
x86/efi: Add a prototype for efi_arch_mem_reserve()
x86/mm: Mark setup_emu2phys_nid() static
x86/jump_label: Move 'inline' keyword placement
x86/platform/uv: Add a missing prototype for uv_bau_message_interrupt()
kill uaccess_try()
x86: unsafe_put-style macro for sigmask
x86: x32_setup_rt_frame(): consolidate uaccess areas
x86: __setup_rt_frame(): consolidate uaccess areas
x86: __setup_frame(): consolidate uaccess areas
x86: setup_sigcontext(): list user_access_{begin,end}() into callers
x86: get rid of put_user_try in __setup_rt_frame() (both 32bit and 64bit)
x86: ia32_setup_rt_frame(): consolidate uaccess areas
x86: ia32_setup_frame(): consolidate uaccess areas
x86: ia32_setup_sigcontext(): lift user_access_{begin,end}() into the callers
x86/alternatives: Mark text_poke_loc_init() static
x86/cpu: Fix a -Wmissing-prototypes warning for init_ia32_feat_ctl()
x86/mm: Drop pud_mknotpresent()
x86: Replace setup_irq() by request_irq()
x86/configs: Slightly reduce defconfigs
...
Pull EFI updates from Ingo Molnar:
"The EFI changes in this cycle are much larger than usual, for two
(positive) reasons:
- The GRUB project is showing signs of life again, resulting in the
introduction of the generic Linux/UEFI boot protocol, instead of
x86 specific hacks which are increasingly difficult to maintain.
There's hope that all future extensions will now go through that
boot protocol.
- Preparatory work for RISC-V EFI support.
The main changes are:
- Boot time GDT handling changes
- Simplify handling of EFI properties table on arm64
- Generic EFI stub cleanups, to improve command line handling, file
I/O, memory allocation, etc.
- Introduce a generic initrd loading method based on calling back
into the firmware, instead of relying on the x86 EFI handover
protocol or device tree.
- Introduce a mixed mode boot method that does not rely on the x86
EFI handover protocol either, and could potentially be adopted by
other architectures (if another one ever surfaces where one
execution mode is a superset of another)
- Clean up the contents of 'struct efi', and move out everything that
doesn't need to be stored there.
- Incorporate support for UEFI spec v2.8A changes that permit
firmware implementations to return EFI_UNSUPPORTED from UEFI
runtime services at OS runtime, and expose a mask of which ones are
supported or unsupported via a configuration table.
- Partial fix for the lack of by-VA cache maintenance in the
decompressor on 32-bit ARM.
- Changes to load device firmware from EFI boot service memory
regions
- Various documentation updates and minor code cleanups and fixes"
* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (114 commits)
efi/libstub/arm: Fix spurious message that an initrd was loaded
efi/libstub/arm64: Avoid image_base value from efi_loaded_image
partitions/efi: Fix partition name parsing in GUID partition entry
efi/x86: Fix cast of image argument
efi/libstub/x86: Use ULONG_MAX as upper bound for all allocations
efi: Fix a mistype in comments mentioning efivar_entry_iter_begin()
efi/libstub: Avoid linking libstub/lib-ksyms.o into vmlinux
efi/x86: Preserve %ebx correctly in efi_set_virtual_address_map()
efi/x86: Ignore the memory attributes table on i386
efi/x86: Don't relocate the kernel unless necessary
efi/x86: Remove extra headroom for setup block
efi/x86: Add kernel preferred address to PE header
efi/x86: Decompress at start of PE image load address
x86/boot/compressed/32: Save the output address instead of recalculating it
efi/libstub/x86: Deal with exit() boot service returning
x86/boot: Use unsigned comparison for addresses
efi/x86: Avoid using code32_start
efi/x86: Make efi32_pe_entry() more readable
efi/x86: Respect 32-bit ABI in efi32_pe_entry()
efi/x86: Annotate the LOADED_IMAGE_PROTOCOL_GUID with SYM_DATA
...
Provide more information about __ex_table sorting post link.
The exception tables and fixup tables use a commonly recurring pattern
in the kernel of storing the address of labels as date in custom ELF
sections, then finding these sections, iterating elements within them,
and possibly revisiting them or modifying the data at these addresses.
Sorting readonly arrays to minimize runtime penalties is quite clever.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20200327000951.84071-1-ndesaulniers@google.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
