Commit Graph

715 Commits

Author SHA1 Message Date
Linus Torvalds
6f664045c8 Merge tag 'mm-nonmm-stable-2022-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc updates from Andrew Morton:
 "The non-MM patch queue for this merge window.

  Not a lot of material this cycle. Many singleton patches against
  various subsystems. Most notably some maintenance work in ocfs2
  and initramfs"

* tag 'mm-nonmm-stable-2022-05-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (65 commits)
  kcov: update pos before writing pc in trace function
  ocfs2: dlmfs: fix error handling of user_dlm_destroy_lock
  ocfs2: dlmfs: don't clear USER_LOCK_ATTACHED when destroying lock
  fs/ntfs: remove redundant variable idx
  fat: remove time truncations in vfat_create/vfat_mkdir
  fat: report creation time in statx
  fat: ignore ctime updates, and keep ctime identical to mtime in memory
  fat: split fat_truncate_time() into separate functions
  MAINTAINERS: add Muchun as a memcg reviewer
  proc/sysctl: make protected_* world readable
  ia64: mca: drop redundant spinlock initialization
  tty: fix deadlock caused by calling printk() under tty_port->lock
  relay: remove redundant assignment to pointer buf
  fs/ntfs3: validate BOOT sectors_per_clusters
  lib/string_helpers: fix not adding strarray to device's resource list
  kernel/crash_core.c: remove redundant check of ck_cmdline
  ELF, uapi: fixup ELF_ST_TYPE definition
  ipc/mqueue: use get_tree_nodev() in mqueue_get_tree()
  ipc: update semtimedop() to use hrtimer
  ipc/sem: remove redundant assignments
  ...
2022-05-27 11:22:03 -07:00
Linus Torvalds
abc8babefb Merge tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 updates from Borislav Petkov:
 "A variety of fixes which don't fit any other tip bucket:

   - Remove unnecessary function export

   - Correct asm constraint

   - Fix __setup handlers retval"

* tag 'x86_misc_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Cleanup the control_va_addr_alignment() __setup handler
  x86: Fix return value of __setup handlers
  x86/delay: Fix the wrong asm constraint in delay_loop()
  x86/amd_nb: Unexport amd_cache_northbridges()
2022-05-23 19:32:59 -07:00
Linus Torvalds
de8ac81747 Merge tag 'x86_core_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core x86 updates from Borislav Petkov:

 - Remove all the code around GS switching on 32-bit now that it is not
   needed anymore

 - Other misc improvements

* tag 'x86_core_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  bug: Use normal relative pointers in 'struct bug_entry'
  x86/nmi: Make register_nmi_handler() more robust
  x86/asm: Merge load_gs_index()
  x86/32: Remove lazy GS macros
  ELF: Remove elf_core_copy_kernel_regs()
  x86/32: Simplify ELF_CORE_COPY_REGS
2022-05-23 18:42:07 -07:00
Linus Torvalds
a13dc4d409 Merge tag 'x86_cleanups_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Borislav Petkov:

 - Serious sanitization and cleanup of the whole APERF/MPERF and
   frequency invariance code along with removing the need for
   unnecessary IPIs

 - Finally remove a.out support

 - The usual trivial cleanups and fixes all over x86

* tag 'x86_cleanups_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  x86: Remove empty files
  x86/speculation: Add missing srbds=off to the mitigations= help text
  x86/prctl: Remove pointless task argument
  x86/aperfperf: Make it correct on 32bit and UP kernels
  x86/aperfmperf: Integrate the fallback code from show_cpuinfo()
  x86/aperfmperf: Replace arch_freq_get_on_cpu()
  x86/aperfmperf: Replace aperfmperf_get_khz()
  x86/aperfmperf: Store aperf/mperf data for cpu frequency reads
  x86/aperfmperf: Make parts of the frequency invariance code unconditional
  x86/aperfmperf: Restructure arch_scale_freq_tick()
  x86/aperfmperf: Put frequency invariance aperf/mperf data into a struct
  x86/aperfmperf: Untangle Intel and AMD frequency invariance init
  x86/aperfmperf: Separate AP/BP frequency invariance init
  x86/smp: Move APERF/MPERF code where it belongs
  x86/aperfmperf: Dont wake idle CPUs in arch_freq_get_on_cpu()
  x86/process: Fix kernel-doc warning due to a changed function name
  x86: Remove a.out support
  x86/mm: Replace nodes_weight() with nodes_empty() where appropriate
  x86: Replace cpumask_weight() with cpumask_empty() where appropriate
  x86/pkeys: Remove __arch_set_user_pkey_access() declaration
  ...
2022-05-23 18:17:09 -07:00
Linus Torvalds
3a755ebcc2 Merge tag 'x86_tdx_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull Intel TDX support from Borislav Petkov:
 "Intel Trust Domain Extensions (TDX) support.

  This is the Intel version of a confidential computing solution called
  Trust Domain Extensions (TDX). This series adds support to run the
  kernel as part of a TDX guest. It provides similar guest protections
  to AMD's SEV-SNP like guest memory and register state encryption,
  memory integrity protection and a lot more.

  Design-wise, it differs from AMD's solution considerably: it uses a
  software module which runs in a special CPU mode called (Secure
  Arbitration Mode) SEAM. As the name suggests, this module serves as
  sort of an arbiter which the confidential guest calls for services it
  needs during its lifetime.

  Just like AMD's SNP set, this series reworks and streamlines certain
  parts of x86 arch code so that this feature can be properly
  accomodated"

* tag 'x86_tdx_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
  x86/tdx: Fix RETs in TDX asm
  x86/tdx: Annotate a noreturn function
  x86/mm: Fix spacing within memory encryption features message
  x86/kaslr: Fix build warning in KASLR code in boot stub
  Documentation/x86: Document TDX kernel architecture
  ACPICA: Avoid cache flush inside virtual machines
  x86/tdx/ioapic: Add shared bit for IOAPIC base address
  x86/mm: Make DMA memory shared for TD guest
  x86/mm/cpa: Add support for TDX shared memory
  x86/tdx: Make pages shared in ioremap()
  x86/topology: Disable CPU online/offline control for TDX guests
  x86/boot: Avoid #VE during boot for TDX platforms
  x86/boot: Set CR0.NE early and keep it set during the boot
  x86/acpi/x86/boot: Add multiprocessor wake-up support
  x86/boot: Add a trampoline for booting APs via firmware handoff
  x86/tdx: Wire up KVM hypercalls
  x86/tdx: Port I/O: Add early boot support
  x86/tdx: Port I/O: Add runtime hypercalls
  x86/boot: Port I/O: Add decompression-time support for TDX
  x86/boot: Port I/O: Allow to hook up alternative helpers
  ...
2022-05-23 17:51:12 -07:00
Borislav Petkov
d936411dc9 x86: Remove empty files
Remove empty files which were supposed to get removed with the
respective commits removing the functionality in them:

$ find arch/x86/ -empty
arch/x86/lib/mmx_32.c
arch/x86/include/asm/fpu/internal.h
arch/x86/include/asm/mmx.h

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220520101723.12006-1-bp@alien8.de
2022-05-20 12:29:26 +02:00
Linus Torvalds
b2da7df52e Merge tag 'x86_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:

 - A fix to disable PCI/MSI[-X] masking for XEN_HVM guests as that is
   solely controlled by the hypervisor

 - A build fix to make the function prototype (__warn()) as visible as
   the definition itself

 - A bunch of objtool annotation fixes which have accumulated over time

 - An ORC unwinder fix to handle bad input gracefully

 - Well, we thought the microcode gets loaded in time in order to
   restore the microcode-emulated MSRs but we thought wrong. So there's
   a fix for that to have the ordering done properly

 - Add new Intel model numbers

 - A spelling fix

* tag 'x86_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pci/xen: Disable PCI/MSI[-X] masking for XEN_HVM guests
  bug: Have __warn() prototype defined unconditionally
  x86/Kconfig: fix the spelling of 'becoming' in X86_KERNEL_IBT config
  objtool: Use offstr() to print address of missing ENDBR
  objtool: Print data address for "!ENDBR" data warnings
  x86/xen: Add ANNOTATE_NOENDBR to startup_xen()
  x86/uaccess: Add ENDBR to __put_user_nocheck*()
  x86/retpoline: Add ANNOTATE_NOENDBR for retpolines
  x86/static_call: Add ANNOTATE_NOENDBR to static call trampoline
  objtool: Enable unreachable warnings for CLANG LTO
  x86,objtool: Explicitly mark idtentry_body()s tail REACHABLE
  x86,objtool: Mark cpu_startup_entry() __noreturn
  x86,xen,objtool: Add UNWIND hint
  lib/strn*,objtool: Enforce user_access_begin() rules
  MAINTAINERS: Add x86 unwinding entry
  x86/unwind/orc: Recheck address range after stack info was updated
  x86/cpu: Load microcode during restore_processor_state()
  x86/cpu: Add new Alderlake and Raptorlake CPU model numbers
2022-05-01 10:03:36 -07:00
Linus Torvalds
b70ed23c23 Merge tag 'objtool_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fixes from Borislav Petkov:
 "A bunch of objtool fixes to improve unwinding, sibling call detection,
  fallthrough detection and relocation handling of weak symbols when the
  toolchain strips section symbols"

* tag 'objtool_urgent_for_v5.18_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix code relocs vs weak symbols
  objtool: Fix type of reloc::addend
  objtool: Fix function fallthrough detection for vmlinux
  objtool: Fix sibling call detection in alternatives
  objtool: Don't set 'jump_dest' for sibling calls
  x86/uaccess: Don't jump between functions
2022-05-01 09:34:54 -07:00
Christoph Hellwig
6308499b5e net: unexport csum_and_copy_{from,to}_user
csum_and_copy_from_user and csum_and_copy_to_user are exported by a few
architectures, but not actually used in modular code.  Drop the exports.

Link: https://lkml.kernel.org/r/20220421070440.1282704-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-29 14:37:59 -07:00
Mikulas Patocka
a6823e4e36 x86: __memcpy_flushcache: fix wrong alignment if size > 2^32
The first "if" condition in __memcpy_flushcache is supposed to align the
"dest" variable to 8 bytes and copy data up to this alignment.  However,
this condition may misbehave if "size" is greater than 4GiB.

The statement min_t(unsigned, size, ALIGN(dest, 8) - dest); casts both
arguments to unsigned int and selects the smaller one.  However, the
cast truncates high bits in "size" and it results in misbehavior.

For example:

	suppose that size == 0x100000001, dest == 0x200000002
	min_t(unsigned, size, ALIGN(dest, 8) - dest) == min_t(0x1, 0xe) == 0x1;
	...
	dest += 0x1;

so we copy just one byte "and" dest remains unaligned.

This patch fixes the bug by replacing unsigned with size_t.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-04-20 11:38:49 -07:00
Josh Poimboeuf
02041b3225 x86/uaccess: Don't jump between functions
For unwinding sanity, a function shouldn't jump to the middle of another
function.  Move the short string user copy code out to a separate
non-function code snippet.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/9519e4853148b765e047967708f2b61e56c93186.1649718562.git.jpoimboe@redhat.com
2022-04-19 21:58:53 +02:00
Josh Poimboeuf
7a00829f8a x86/uaccess: Add ENDBR to __put_user_nocheck*()
The __put_user_nocheck*() inner labels are exported, so in keeping with
the "allow exported functions to be indirectly called" policy, add
ENDBR.

Fixes: ed53a0d971 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/207f02177a23031091d1a608de6049a9e5e8ff80.1650300597.git.jpoimboe@redhat.com
2022-04-19 21:58:49 +02:00
Josh Poimboeuf
1c0513dec4 x86/retpoline: Add ANNOTATE_NOENDBR for retpolines
The retpolines are exported, so they're referenced by ksymtab sections.
But they're never indirect-branched to, so add ANNOTATE_NOENDBR.

Fixes: ed53a0d971 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/b6ec963dfd9301b6b1d74ef7758fcb0b540d6c6c.1650300597.git.jpoimboe@redhat.com
2022-04-19 21:58:49 +02:00
Brian Gerst
3a24a60854 x86/32: Remove lazy GS macros
GS is always a user segment now.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220325153953.162643-4-brgerst@gmail.com
2022-04-14 14:09:43 +02:00
Kirill A. Shutemov
adb5680b8d x86/kaslr: Fix build warning in KASLR code in boot stub
lib/kaslr.c is used by both the main kernel and the boot stub. It
includes asm/io.h which is supposed to be used in the main kernel. It
leads to build warnings like this with clang 13:

  warning: implicit declaration of function 'outl' is invalid in C99 [-Wimplicit-function-declaration]

Replace <asm/io.h> with <asm/shared/io.h> which is suitable for both
cases.

Fixes: 1e8f93e183 ("x86: Consolidate port I/O helpers")
Reported-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220410200025.3stf4jjvwfe5oxew@box.shutemov.name
2022-04-11 09:41:12 +02:00
Ammar Faizi
b86eb74098 x86/delay: Fix the wrong asm constraint in delay_loop()
The asm constraint does not reflect the fact that the asm statement can
modify the value of the local variable loops. Which it does.

Specifying the wrong constraint may lead to undefined behavior, it may
clobber random stuff (e.g. local variable, important temporary value in
regs, etc.). This is especially dangerous when the compiler decides to
inline the function and since it doesn't know that the value gets
modified, it might decide to use it from a register directly without
reloading it.

Change the constraint to "+a" to denote that the first argument is an
input and an output argument.

  [ bp: Fix typo, massage commit message. ]

Fixes: e01b70ef3e ("x86: fix bug in arch/i386/lib/delay.c file, delay_loop function")
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220329104705.65256-2-ammarfaizi2@gnuweeb.org
2022-04-05 21:21:57 +02:00
Linus Torvalds
8b5656bc4e Merge tag 'x86-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "A set of x86 fixes and updates:

   - Make the prctl() for enabling dynamic XSTATE components correct so
     it adds the newly requested feature to the permission bitmap
     instead of overwriting it. Add a selftest which validates that.

   - Unroll string MMIO for encrypted SEV guests as the hypervisor
     cannot emulate it.

   - Handle supervisor states correctly in the FPU/XSTATE code so it
     takes the feature set of the fpstate buffer into account. The
     feature sets can differ between host and guest buffers. Guest
     buffers do not contain supervisor states. So far this was not an
     issue, but with enabling PASID it needs to be handled in the buffer
     offset calculation and in the permission bitmaps.

   - Avoid a gazillion of repeated CPUID invocations in by caching the
     values early in the FPU/XSTATE code.

   - Enable CONFIG_WERROR in x86 defconfig.

   - Make the X86 defconfigs more useful by adapting them to Y2022
     reality"

* tag 'x86-urgent-2022-04-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu/xstate: Consolidate size calculations
  x86/fpu/xstate: Handle supervisor states in XSTATE permissions
  x86/fpu/xsave: Handle compacted offsets correctly with supervisor states
  x86/fpu: Cache xfeature flags from CPUID
  x86/fpu/xsave: Initialize offset/size cache early
  x86/fpu: Remove unused supervisor only offsets
  x86/fpu: Remove redundant XCOMP_BV initialization
  x86/sev: Unroll string mmio with CC_ATTR_GUEST_UNROLL_STRING_IO
  x86/config: Make the x86 defconfigs a bit more usable
  x86/defconfig: Enable WERROR
  selftests/x86/amx: Update the ARCH_REQ_XCOMP_PERM test
  x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation
2022-04-03 12:15:47 -07:00
Linus Torvalds
88e6c02076 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "Assorted bits and pieces"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: drop needless assignment in aio_read()
  clean overflow checks in count_mounts() a bit
  seq_file: fix NULL pointer arithmetic warning
  uml/x86: use x86 load_unaligned_zeropad()
  asm/user.h: killed unused macros
  constify struct path argument of finish_automount()/do_add_mount()
  fs: Remove FIXME comment in generic_write_checks()
2022-04-01 19:57:03 -07:00
Joerg Roedel
4009a4ac82 x86/sev: Unroll string mmio with CC_ATTR_GUEST_UNROLL_STRING_IO
The io-specific memcpy/memset functions use string mmio accesses to do
their work. Under SEV, the hypervisor can't emulate these instructions
because they read/write directly from/to encrypted memory.

KVM will inject a page fault exception into the guest when it is asked
to emulate string mmio instructions for an SEV guest:

  BUG: unable to handle page fault for address: ffffc90000065068
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 8000100000067 P4D 8000100000067 PUD 80001000fb067 PMD 80001000fc067 PTE 80000000fed40173
  Oops: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-rc7 #3

As string mmio for an SEV guest can not be supported by the
hypervisor, unroll the instructions for CC_ATTR_GUEST_UNROLL_STRING_IO
enabled kernels.

This issue appears when kernels are launched in recent libvirt-managed
SEV virtual machines, because virt-install started to add a tpm-crb
device to the guest by default and proactively because, raisins:

  eb58c09f48

and as that commit says, the default adding of a TPM can be disabled
with "virt-install ... --tpm none".

The kernel driver for tpm-crb uses memcpy_to/from_io() functions to
access MMIO memory, resulting in a page-fault injected by KVM and
crashing the kernel at boot.

  [ bp: Massage and extend commit message. ]

Fixes: d8aa7eea78 ('x86/mm: Add Secure Encrypted Virtualization (SEV) support')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220321093351.23976-1-joro@8bytes.org
2022-03-29 15:59:16 +02:00
Linus Torvalds
7001052160 Merge tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
 "Add support for Intel CET-IBT, available since Tigerlake (11th gen),
  which is a coarse grained, hardware based, forward edge
  Control-Flow-Integrity mechanism where any indirect CALL/JMP must
  target an ENDBR instruction or suffer #CP.

  Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
  is limited to 2 instructions (and typically fewer) on branch targets
  not starting with ENDBR. CET-IBT also limits speculation of the next
  sequential instruction after the indirect CALL/JMP [1].

  CET-IBT is fundamentally incompatible with retpolines, but provides,
  as described above, speculation limits itself"

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  kvm/emulate: Fix SETcc emulation for ENDBR
  x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld >= 14.0.0
  x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang >= 14.0.0
  kbuild: Fixup the IBT kbuild changes
  x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
  x86: Remove toolchain check for X32 ABI capability
  x86/alternative: Use .ibt_endbr_seal to seal indirect calls
  objtool: Find unused ENDBR instructions
  objtool: Validate IBT assumptions
  objtool: Add IBT/ENDBR decoding
  objtool: Read the NOENDBR annotation
  x86: Annotate idtentry_df()
  x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
  x86: Annotate call_on_stack()
  objtool: Rework ASM_REACHABLE
  x86: Mark __invalid_creds() __noreturn
  exit: Mark do_group_exit() __noreturn
  x86: Mark stop_this_cpu() __noreturn
  objtool: Ignore extra-symbol code
  objtool: Rename --duplicate to --lto
  ...
2022-03-27 10:17:23 -07:00
Linus Torvalds
4be240b18a Merge tag 'memcpy-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull FORTIFY_SOURCE updates from Kees Cook:
 "This series consists of two halves:

   - strict compile-time buffer size checking under FORTIFY_SOURCE for
     the memcpy()-family of functions (for extensive details and
     rationale, see the first commit)

   - enabling FORTIFY_SOURCE for Clang, which has had many overlapping
     bugs that we've finally worked past"

* tag 'memcpy-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  fortify: Add Clang support
  fortify: Make sure strlen() may still be used as a constant expression
  fortify: Use __diagnose_as() for better diagnostic coverage
  fortify: Make pointer arguments const
  Compiler Attributes: Add __diagnose_as for Clang
  Compiler Attributes: Add __overloadable for Clang
  Compiler Attributes: Add __pass_object_size for Clang
  fortify: Replace open-coded __gnu_inline attribute
  fortify: Update compile-time tests for Clang 14
  fortify: Detect struct member overflows in memset() at compile-time
  fortify: Detect struct member overflows in memmove() at compile-time
  fortify: Detect struct member overflows in memcpy() at compile-time
2022-03-26 12:19:04 -07:00
Linus Torvalds
194dfe88d6 Merge tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic updates from Arnd Bergmann:
 "There are three sets of updates for 5.18 in the asm-generic tree:

   - The set_fs()/get_fs() infrastructure gets removed for good.

     This was already gone from all major architectures, but now we can
     finally remove it everywhere, which loses some particularly tricky
     and error-prone code. There is a small merge conflict against a
     parisc cleanup, the solution is to use their new version.

   - The nds32 architecture ends its tenure in the Linux kernel.

     The hardware is still used and the code is in reasonable shape, but
     the mainline port is not actively maintained any more, as all
     remaining users are thought to run vendor kernels that would never
     be updated to a future release.

   - A series from Masahiro Yamada cleans up some of the uapi header
     files to pass the compile-time checks"

* tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits)
  nds32: Remove the architecture
  uaccess: remove CONFIG_SET_FS
  ia64: remove CONFIG_SET_FS support
  sh: remove CONFIG_SET_FS support
  sparc64: remove CONFIG_SET_FS support
  lib/test_lockup: fix kernel pointer check for separate address spaces
  uaccess: generalize access_ok()
  uaccess: fix type mismatch warnings from access_ok()
  arm64: simplify access_ok()
  m68k: fix access_ok for coldfire
  MIPS: use simpler access_ok()
  MIPS: Handle address errors for accesses above CPU max virtual user address
  uaccess: add generic __{get,put}_kernel_nofault
  nios2: drop access_ok() check from __put_user()
  x86: use more conventional access_ok() definition
  x86: remove __range_not_ok()
  sparc64: add __{get,put}_kernel_nofault()
  nds32: fix access_ok() checks in get/put_user
  uaccess: fix nios2 and microblaze get_user_8()
  sparc64: fix building assembly files
  ...
2022-03-23 18:03:08 -07:00
Linus Torvalds
2268735045 Merge tag 'x86_misc_for_v5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 updates from Borislav Petkov:

 - Add support for a couple new insn sets to the insn decoder:
   AVX512-FP16, AMX, other misc insns.

 - Update VMware-specific MAINTAINERS entries

* tag 'x86_misc_for_v5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Mark VMware mailing list entries as email aliases
  MAINTAINERS: Add Zack as maintainer of vmmouse driver
  MAINTAINERS: Update maintainers for paravirt ops and VMware hypervisor interface
  x86/insn: Add AVX512-FP16 instructions to the x86 instruction decoder
  perf/tests: Add AVX512-FP16 instructions to x86 instruction decoder test
  x86/insn: Add misc instructions to x86 instruction decoder
  perf/tests: Add misc instructions to the x86 instruction decoder test
  x86/insn: Add AMX instructions to the x86 instruction decoder
  perf/tests: Add AMX instructions to x86 instruction decoder test
2022-03-21 11:19:00 -07:00
Linus Torvalds
356a1adca8 Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:

 - Support for including MTE tags in ELF coredumps

 - Instruction encoder updates, including fixes to 64-bit immediate
   generation and support for the LSE atomic instructions

 - Improvements to kselftests for MTE and fpsimd

 - Symbol aliasing and linker script cleanups

 - Reduce instruction cache maintenance performed for user mappings
   created using contiguous PTEs

 - Support for the new "asymmetric" MTE mode, where stores are checked
   asynchronously but loads are checked synchronously

 - Support for the latest pointer authentication algorithm ("QARMA3")

 - Support for the DDR PMU present in the Marvell CN10K platform

 - Support for the CPU PMU present in the Apple M1 platform

 - Use the RNDR instruction for arch_get_random_{int,long}()

 - Update our copy of the Arm optimised string routines for str{n}cmp()

 - Fix signal frame generation for CPUs which have foolishly elected to
   avoid building in support for the fpsimd instructions

 - Workaround for Marvell GICv3 erratum #38545

 - Clarification to our Documentation (booting reqs. and MTE prctl())

 - Miscellanous cleanups and minor fixes

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (90 commits)
  docs: sysfs-devices-system-cpu: document "asymm" value for mte_tcf_preferred
  arm64/mte: Remove asymmetric mode from the prctl() interface
  arm64: Add cavium_erratum_23154_cpus missing sentinel
  perf/marvell: Fix !CONFIG_OF build for CN10K DDR PMU driver
  arm64: mm: Drop 'const' from conditional arm64_dma_phys_limit definition
  Documentation: vmcoreinfo: Fix htmldocs warning
  kasan: fix a missing header include of static_keys.h
  drivers/perf: Add Apple icestorm/firestorm CPU PMU driver
  drivers/perf: arm_pmu: Handle 47 bit counters
  arm64: perf: Consistently make all event numbers as 16-bits
  arm64: perf: Expose some Armv9 common events under sysfs
  perf/marvell: cn10k DDR perf event core ownership
  perf/marvell: cn10k DDR perfmon event overflow handling
  perf/marvell: CN10k DDR performance monitor support
  dt-bindings: perf: marvell: cn10k ddr performance monitor
  arm64: clean up tools Makefile
  perf/arm-cmn: Update watchpoint format
  perf/arm-cmn: Hide XP PUB events for CMN-600
  arm64: drop unused includes of <linux/personality.h>
  arm64: Do not defer reserve_crashkernel() for platforms with no DMA memory zones
  ...
2022-03-21 10:46:39 -07:00
Peter Zijlstra
3e3f069504 x86/ibt: Annotate text references
Annotate away some of the generic code references. This is things
where we take the address of a symbol for exception handling or return
addresses (eg. context switch).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154318.877758523@infradead.org
2022-03-15 10:32:40 +01:00
Peter Zijlstra
599d66b847 Merge branch 'arm64/for-next/linkage'
Enjoy the cleanups and avoid conflicts vs linkage

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2022-03-15 10:32:31 +01:00
Arnd Bergmann
36903abedf x86: remove __range_not_ok()
The __range_not_ok() helper is an x86 (and sparc64) specific interface
that does roughly the same thing as __access_ok(), but with different
calling conventions.

Change this to use the normal interface in order for consistency as we
clean up all access_ok() implementations.

This changes the limit from TASK_SIZE to TASK_SIZE_MAX, which Al points
out is the right thing do do here anyway.

The callers have to use __access_ok() instead of the normal access_ok()
though, because on x86 that contains a WARN_ON_IN_IRQ() check that cannot
be used inside of NMI context while tracing.

The check in copy_code() is not needed any more, because this one is
already done by copy_from_user_nmi().

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Link: https://lore.kernel.org/lkml/YgsUKcXGR7r4nINj@zeniv-ca.linux.org.uk/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-02-25 09:36:05 +01:00
Mark Rutland
7be2e31964 x86: clean up symbol aliasing
Now that we have SYM_FUNC_ALIAS() and SYM_FUNC_ALIAS_WEAK(), use those
to simplify the definition of function aliases across arch/x86.

For clarity, where there are multiple annotations such as
EXPORT_SYMBOL(), I've tried to keep annotations grouped by symbol. For
example, where a function has a name and an alias which are both
exported, this is organised as:

	SYM_FUNC_START(func)
	    ... asm insns ...
	SYM_FUNC_END(func)
	EXPORT_SYMBOL(func)

	SYM_FUNC_ALIAS(alias, func)
	EXPORT_SYMBOL(alias)

Where there are only aliases and no exports or other annotations, I have
not bothered with line spacing, e.g.

	SYM_FUNC_START(func)
	    ... asm insns ...
	SYM_FUNC_END(func)
	SYM_FUNC_ALIAS(alias, func)

The tools/perf/ copies of memset_64.S and memset_64.S are updated
likewise to avoid the build system complaining these are mismatched:

| Warning: Kernel ABI header at 'tools/arch/x86/lib/memcpy_64.S' differs from latest version at 'arch/x86/lib/memcpy_64.S'
| diff -u tools/arch/x86/lib/memcpy_64.S arch/x86/lib/memcpy_64.S
| Warning: Kernel ABI header at 'tools/arch/x86/lib/memset_64.S' differs from latest version at 'arch/x86/lib/memset_64.S'
| diff -u tools/arch/x86/lib/memset_64.S arch/x86/lib/memset_64.S

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Mark Brown <broonie@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220216162229.1076788-4-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
2022-02-22 16:21:34 +00:00
Peter Zijlstra (Intel)
d45476d983 x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE
The RETPOLINE_AMD name is unfortunate since it isn't necessarily
AMD only, in fact Hygon also uses it. Furthermore it will likely be
sufficient for some Intel processors. Therefore rename the thing to
RETPOLINE_LFENCE to better describe what it is.

Add the spectre_v2=retpoline,lfence option as an alias to
spectre_v2=retpoline,amd to preserve existing setups. However, the output
of /sys/devices/system/cpu/vulnerabilities/spectre_v2 will be changed.

  [ bp: Fix typos, massage. ]

Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2022-02-21 10:21:28 +01:00
Kees Cook
938a000e3f fortify: Detect struct member overflows in memmove() at compile-time
As done for memcpy(), also update memmove() to use the same tightened
compile-time checks under CONFIG_FORTIFY_SOURCE.

Signed-off-by: Kees Cook <keescook@chromium.org>
2022-02-13 16:50:06 -08:00
Al Viro
6692531df6 uml/x86: use x86 load_unaligned_zeropad()
allows, among other things, to drop !DCACHE_WORD_ACCESS mess in
x86 csum-partial_64.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-01-30 21:26:39 -05:00
Adrian Hunter
16273fa4f3 x86/insn: Add AVX512-FP16 instructions to the x86 instruction decoder
The x86 instruction decoder is used for both kernel instructions and
user space instructions (e.g. uprobes, perf tools Intel PT), so it is
good to update it with new instructions.

Add AVX512-FP16 instructions to x86 instruction decoder.

Note the EVEX map field is extended by 1 bit, and most instructions are in
map 5 and map 6.

Reference:
Intel AVX512-FP16 Architecture Specification
June 2021
Revision 1.0
Document Number: 347407-001US

Example using perf tools' x86 instruction decoder test:

  $ perf test -v "x86 instruction decoder" |& grep vfcmaddcph | head -2
  Decoded ok: 62 f6 6f 48 56 cb           vfcmaddcph %zmm3,%zmm2,%zmm1
  Decoded ok: 62 f6 6f 48 56 8c c8 78 56 34 12    vfcmaddcph 0x12345678(%eax,%ecx,8),%zmm2,%zmm1

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20211202095029.2165714-7-adrian.hunter@intel.com
2022-01-23 20:38:01 +01:00
Adrian Hunter
0153d98f2d x86/insn: Add misc instructions to x86 instruction decoder
x86 instruction decoder is used for both kernel instructions and user space
instructions (e.g. uprobes, perf tools Intel PT), so it is good to update
it with new instructions.

Add instructions to x86 instruction decoder:

	User Interrupt

		clui
		senduipi
		stui
		testui
		uiret

	Prediction history reset

		hreset

	Serialize instruction execution

		serialize

	TSX suspend load address tracking

		xresldtrk
		xsusldtrk

Reference:
Intel Architecture Instruction Set Extensions and Future Features
Programming Reference
May 2021
Document Number: 319433-044

Example using perf tools' x86 instruction decoder test:

  $ perf test -v "x86 instruction decoder" |& grep -i hreset
  Decoded ok: f3 0f 3a f0 c0 00           hreset $0x0
  Decoded ok: f3 0f 3a f0 c0 00           hreset $0x0

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20211202095029.2165714-5-adrian.hunter@intel.com
2022-01-23 20:37:54 +01:00
Adrian Hunter
9dd94df75b x86/insn: Add AMX instructions to the x86 instruction decoder
The x86 instruction decoder is used for both kernel instructions and
user space instructions (e.g. uprobes, perf tools Intel PT), so it is
good to update it with new instructions.

Add AMX instructions to the x86 instruction decoder.

Reference:
Intel Architecture Instruction Set Extensions and Future Features
Programming Reference
May 2021
Document Number: 319433-044

Example using perf tools' x86 instruction decoder test:

  $ INSN='ldtilecfg\|sttilecfg\|tdpbf16ps\|tdpbssd\|'
  $ INSN+='tdpbsud\|tdpbusd\|'tdpbuud\|tileloadd\|'
  $ INSN+='tileloaddt1\|tilerelease\|tilestored\|tilezero'
  $ perf test -v "x86 instruction decoder" |& grep -i $INSN
  Decoded ok: c4 e2 78 49 04 c8    	ldtilecfg (%rax,%rcx,8)
  Decoded ok: c4 c2 78 49 04 c8    	ldtilecfg (%r8,%rcx,8)
  Decoded ok: c4 e2 79 49 04 c8    	sttilecfg (%rax,%rcx,8)
  Decoded ok: c4 c2 79 49 04 c8    	sttilecfg (%r8,%rcx,8)
  Decoded ok: c4 e2 7a 5c d1       	tdpbf16ps %tmm0,%tmm1,%tmm2
  Decoded ok: c4 e2 7b 5e d1       	tdpbssd %tmm0,%tmm1,%tmm2
  Decoded ok: c4 e2 7a 5e d1       	tdpbsud %tmm0,%tmm1,%tmm2
  Decoded ok: c4 e2 79 5e d1       	tdpbusd %tmm0,%tmm1,%tmm2
  Decoded ok: c4 e2 78 5e d1       	tdpbuud %tmm0,%tmm1,%tmm2
  Decoded ok: c4 e2 7b 4b 0c c8    	tileloadd (%rax,%rcx,8),%tmm1
  Decoded ok: c4 c2 7b 4b 14 c8    	tileloadd (%r8,%rcx,8),%tmm2
  Decoded ok: c4 e2 79 4b 0c c8    	tileloaddt1 (%rax,%rcx,8),%tmm1
  Decoded ok: c4 c2 79 4b 14 c8    	tileloaddt1 (%r8,%rcx,8),%tmm2
  Decoded ok: c4 e2 78 49 c0       	tilerelease
  Decoded ok: c4 e2 7a 4b 0c c8    	tilestored %tmm1,(%rax,%rcx,8)
  Decoded ok: c4 c2 7a 4b 14 c8    	tilestored %tmm2,(%r8,%rcx,8)
  Decoded ok: c4 e2 7b 49 c0       	tilezero %tmm0
  Decoded ok: c4 e2 7b 49 f8       	tilezero %tmm7

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20211202095029.2165714-3-adrian.hunter@intel.com
2022-01-23 20:37:46 +01:00
Linus Torvalds
64ad946152 Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Borislav Petkov:

 - Get rid of all the .fixup sections because this generates
   misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
   LIVEPATCH as the backtrace misses the function which is being fixed
   up.

 - Add Straight Line Speculation mitigation support which uses a new
   compiler switch -mharden-sls= which sticks an INT3 after a RET or an
   indirect branch in order to block speculation after them. Reportedly,
   CPUs do speculate behind such insns.

 - The usual set of cleanups and improvements

* tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/entry_32: Fix segment exceptions
  objtool: Remove .fixup handling
  x86: Remove .fixup section
  x86/word-at-a-time: Remove .fixup usage
  x86/usercopy: Remove .fixup usage
  x86/usercopy_32: Simplify __copy_user_intel_nocache()
  x86/sgx: Remove .fixup usage
  x86/checksum_32: Remove .fixup usage
  x86/vmx: Remove .fixup usage
  x86/kvm: Remove .fixup usage
  x86/segment: Remove .fixup usage
  x86/fpu: Remove .fixup usage
  x86/xen: Remove .fixup usage
  x86/uaccess: Remove .fixup usage
  x86/futex: Remove .fixup usage
  x86/msr: Remove .fixup usage
  x86/extable: Extend extable functionality
  x86/entry_32: Remove .fixup usage
  x86/entry_64: Remove .fixup usage
  x86/copy_mc_64: Remove .fixup usage
  ...
2022-01-12 16:31:19 -08:00
Peter Zijlstra
9cdbeec409 x86/entry_32: Fix segment exceptions
The LKP robot reported that commit in Fixes: caused a failure. Turns out
the ldt_gdt_32 selftest turns into an infinite loop trying to clear the
segment.

As discovered by Sean, what happens is that PARANOID_EXIT_TO_KERNEL_MODE
in the handle_exception_return path overwrites the entry stack data with
the task stack data, restoring the "bad" segment value.

Instead of having the exception retry the instruction, have it emulate
the full instruction. Replace EX_TYPE_POP_ZERO with EX_TYPE_POP_REG
which will do the equivalent of: POP %reg; MOV $imm, %reg.

In order to encode the segment registers, add them as registers 8-11 for
32-bit.

By setting regs->[defg]s the (nested) RESTORE_REGS will pop this value
at the end of the exception handler and by increasing regs->sp, it will
have skipped the stack slot.

This was debugged by Sean Christopherson <seanjc@google.com>.

 [ bp: Add EX_REG_GS too. ]

Fixes: aa93e2ad74 ("x86/entry_32: Remove .fixup usage")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/Yd1l0gInc4zRcnt/@hirez.programming.kicks-ass.net
2022-01-12 16:38:25 +01:00
Linus Torvalds
7e740ae635 Merge tag 'ras_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS updates from Borislav Petkov:
 "A relatively big amount of movements in RAS-land this time around:

   - First part of a series to move the AMD address translation code
     from arch/x86/ to amd64_edac as that is its only user anyway

   - Some MCE error injection improvements to the AMD side

   - Reorganization of the #MC handler code and the facilities it calls
     to make it noinstr-safe

   - Add support for new AMD MCA bank types and non-uniform banks layout

   - The usual set of cleanups and fixes"

* tag 'ras_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  x86/mce: Reduce number of machine checks taken during recovery
  x86/mce/inject: Avoid out-of-bounds write when setting flags
  x86/MCE/AMD, EDAC/mce_amd: Support non-uniform MCA bank type enumeration
  x86/MCE/AMD, EDAC/mce_amd: Add new SMCA bank types
  x86/mce: Check regs before accessing it
  x86/mce: Mark mce_start() noinstr
  x86/mce: Mark mce_timed_out() noinstr
  x86/mce: Move the tainting outside of the noinstr region
  x86/mce: Mark mce_read_aux() noinstr
  x86/mce: Mark mce_end() noinstr
  x86/mce: Mark mce_panic() noinstr
  x86/mce: Prevent severity computation from being instrumented
  x86/mce: Allow instrumentation during task work queueing
  x86/mce: Remove noinstr annotation from mce_setup()
  x86/mce: Use mce_rdmsrl() in severity checking code
  x86/mce: Remove function-local cpus variables
  x86/mce: Do not use memset to clear the banks bitmaps
  x86/mce/inject: Set the valid bit in MCA_STATUS before error injection
  x86/mce/inject: Check if a bank is populated before injecting
  x86/mce: Get rid of cpu_missing
  ...
2022-01-10 11:43:09 -08:00
Linus Torvalds
25f8c7785e Merge tag 'x86_cpu_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpuid updates from Borislav Petkov:

 - Enable the short string copies for CPUs which support them, in
   copy_user_enhanced_fast_string()

 - Avoid writing MSR_CSTAR on Intel due to TDX guests raising a #VE trap

* tag 'x86_cpu_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/lib: Add fast-short-rep-movs check to copy_user_enhanced_fast_string()
  x86/cpu: Don't write CSTAR MSR on Intel CPUs
2022-01-10 10:09:22 -08:00
Youquan Song
3376136300 x86/mce: Reduce number of machine checks taken during recovery
When any of the copy functions in arch/x86/lib/copy_user_64.S take a
fault, the fixup code copies the remaining byte count from %ecx to %edx
and unconditionally jumps to .Lcopy_user_handle_tail to continue the
copy in case any more bytes can be copied.

If the fault was #PF this may copy more bytes (because the page fault
handler might have fixed the fault). But when the fault is a machine
check the original copy code will have copied all the way to the poisoned
cache line. So .Lcopy_user_handle_tail will just take another machine
check for no good reason.

Every code path to .Lcopy_user_handle_tail comes from an exception fixup
path, so add a check there to check the trap type (in %eax) and simply
return the count of remaining bytes if the trap was a machine check.

Doing this reduces the number of machine checks taken during synthetic
tests from four to three.

As well as reducing the number of machine checks, this also allows
Skylake generation Xeons to recover some cases that currently fail. The
is because REP; MOVSB is only recoverable when source and destination
are well aligned and the byte count is large. That useless call to
.Lcopy_user_handle_tail may violate one or more of these conditions and
generate a fatal machine check.

  [ Tony: Add more details to commit message. ]
  [ bp: Fixup comment.
    Also, another tip patchset which is adding straight-line speculation
    mitigation changes the "ret" instruction to an all-caps macro "RET".
    But, since gas is case-insensitive, use "RET" in the newly added asm block
    already in order to simplify tip branch merging on its way upstream.
  ]

Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/YcTW5dh8yTGucDd+@agluck-desk2.amr.corp.intel.com
2021-12-31 18:22:32 +01:00
Tony Luck
244122b4d2 x86/lib: Add fast-short-rep-movs check to copy_user_enhanced_fast_string()
Commit

  f444a5ff95 ("x86/cpufeatures: Add support for fast short REP; MOVSB")

fixed memmove() with an ALTERNATIVE that will use REP MOVSB for all
string lengths.

copy_user_enhanced_fast_string() has a similar run time check to avoid
using REP MOVSB for copies less that 64 bytes.

Add an ALTERNATIVE to patch out the short length check and always use
REP MOVSB on X86_FEATURE_FSRM CPUs.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211216172431.1396371-1-tony.luck@intel.com
2021-12-29 13:46:02 +01:00
Peter Zijlstra
d5d797dcbd x86/usercopy: Remove .fixup usage
Typically usercopy does whole word copies followed by a number of byte
copies to finish the tail. This means that on exception it needs to
compute the remaining length as: words*sizeof(long) + bytes.

Create a new extable handler to do just this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20211110101326.081701085@infradead.org
2021-12-11 09:09:50 +01:00
Peter Zijlstra
13e4bf1bdd x86/usercopy_32: Simplify __copy_user_intel_nocache()
Have an exception jump to a .fixup to only immediately jump out is
daft, jump to the right place in one go.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20211110101326.021517780@infradead.org
2021-12-11 09:09:50 +01:00
Peter Zijlstra
fedb24cda1 x86/checksum_32: Remove .fixup usage
Simply add EX_FLAG_CLEAR_AX to do as the .fixup used to do.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20211110101325.899657959@infradead.org
2021-12-11 09:09:49 +01:00
Peter Zijlstra
4b5305decc x86/extable: Extend extable functionality
In order to remove further .fixup usage, extend the extable
infrastructure to take additional information from the extable entry
sites.

Specifically add _ASM_EXTABLE_TYPE_REG() and EX_TYPE_IMM_REG that
extend the existing _ASM_EXTABLE_TYPE() by taking an additional
register argument and encoding that and an s16 immediate into the
existing s32 type field. This limits the actual types to the first
byte, 255 seem plenty.

Also add a few flags into the type word, specifically CLEAR_AX and
CLEAR_DX which clear the return and extended return register.

Notes:
 - due to the % in our register names it's hard to make it more
   generally usable as arm64 did.
 - the s16 is far larger than used in these patches, future extentions
   can easily shrink this to get more bits.
 - without the bitfield fix this will not compile, because: 0xFF > -1
   and we can't even extract the TYPE field.

[nathanchance: Build fix for clang-lto builds:
 https://lkml.kernel.org/r/20211210234953.3420108-1-nathan@kernel.org
]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20211110101325.303890153@infradead.org
2021-12-11 09:09:46 +01:00
Peter Zijlstra
ab0fedcc71 x86/copy_mc_64: Remove .fixup usage
Place the anonymous .fixup code at the tail of the regular functions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211110101325.127055887@infradead.org
2021-12-11 09:09:46 +01:00
Peter Zijlstra
acba44d243 x86/copy_user_64: Remove .fixup usage
Place the anonymous .fixup code at the tail of the regular functions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211110101325.068505810@infradead.org
2021-12-11 09:09:45 +01:00
Peter Zijlstra
c6dbd3e5e6 x86/mmx_32: Remove X86_USE_3DNOW
This code puts an exception table entry on the PREFETCH instruction to
overwrite it with a JMP.d8 when it triggers an exception. Except of
course, our code is no longer writable, also SMP.

Instead of fixing this broken mess, simply take it out.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/YZKQzUmeNuwyvZpk@hirez.programming.kicks-ass.net
2021-12-11 09:09:45 +01:00
Peter Zijlstra
e463a09af2 x86: Add straight-line-speculation mitigation
Make use of an upcoming GCC feature to mitigate
straight-line-speculation for x86:

  https://gcc.gnu.org/g:53a643f8568067d7700a9f2facc8ba39974973d3
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952
  https://bugs.llvm.org/show_bug.cgi?id=52323

It's built tested on x86_64-allyesconfig using GCC-12 and GCC-11.

Maintenance overhead of this should be fairly low due to objtool
validation.

Size overhead of all these additional int3 instructions comes to:

     text	   data	    bss	    dec	    hex	filename
  22267751	6933356	2011368	31212475	1dc43bb	defconfig-build/vmlinux
  22804126	6933356	1470696	31208178	1dc32f2	defconfig-build/vmlinux.sls

Or roughly 2.4% additional text.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134908.140103474@infradead.org
2021-12-09 13:32:25 +01:00
Peter Zijlstra
b17c2baa30 x86: Prepare inline-asm for straight-line-speculation
Replace all ret/retq instructions with ASM_RET in preparation of
making it more than a single instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134907.964635458@infradead.org
2021-12-08 19:23:12 +01:00
Peter Zijlstra
f94909ceb1 x86: Prepare asm files for straight-line-speculation
Replace all ret/retq instructions with RET in preparation of making
RET a macro. Since AS is case insensitive it's a big no-op without
RET defined.

  find arch/x86/ -name \*.S | while read file
  do
	sed -i 's/\<ret[q]*\>/RET/' $file
  done

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134907.905503893@infradead.org
2021-12-08 12:25:37 +01:00