linux.git/tools/arch/x86/include/asm, branch v6.5 Linux kernel source tree Merge tag 'perf-tools-fixes-for-v6.5-3-2023-08-09' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux 2023-08-10T04:06:14+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-08-10T04:06:14+00:00 b4f63b0f2d170b9dfae0de3fd2981424873cce2b Pull perf tools fixes from Arnaldo Carvalho de Melo: - Revert a patch that unconditionally resolved addresses to inlines in callchains, something that was done before when DWARF mode was asked for, but could as well be done when just frame pointers (the default) was selected. This enriches the callchains with inlines but the way to resolve it is gross right now, relying on addr2line, and even if we come up with an efficient way of processing all the associated DWARF info for a big file as vmlinux is, this has to be something people opt-in, as it will still result in overheads, so revert it until we get this done in a saner way. - Update the x86 msr-index.h header with the kernel original, no change in tooling output, just addresses a tools/perf build warning. - Resolve a regression where special "tool events", such as "duration_time" were being presented for all CPUs, when it only makes sense to show it for the workload, that is, just once. * tag 'perf-tools-fixes-for-v6.5-3-2023-08-09' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: perf stat: Don't display zero tool counts tools arch x86: Sync the msr-index.h copy with the kernel sources Revert "perf report: Append inlines to non-DWARF callchains" 
Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Revert a patch that unconditionally resolved addresses to inlines in
   callchains, something that was done before when DWARF mode was asked
   for, but could as well be done when just frame pointers (the default)
   was selected.

   This enriches the callchains with inlines but the way to resolve it
   is gross right now, relying on addr2line, and even if we come up with
   an efficient way of processing all the associated DWARF info for a
   big file as vmlinux is, this has to be something people opt-in, as it
   will still result in overheads, so revert it until we get this done
   in a saner way.

 - Update the x86 msr-index.h header with the kernel original, no change
   in tooling output, just addresses a tools/perf build warning.

  - Resolve a regression where special "tool events", such as
    "duration_time" were being presented for all CPUs, when it only
    makes sense to show it for the workload, that is, just once.

* tag 'perf-tools-fixes-for-v6.5-3-2023-08-09' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf stat: Don't display zero tool counts
  tools arch x86: Sync the msr-index.h copy with the kernel sources
  Revert "perf report: Append inlines to non-DWARF callchains"
tools arch x86: Sync the msr-index.h copy with the kernel sources 2023-08-08T13:52:32+00:00 Arnaldo Carvalho de Melo acme@redhat.com 2023-08-07T13:41:42+00:00 8cdd4aeff2e858c95bb088409028893cfb4e53d4 To pick up the changes from these csets: 522b1d69219d8f08 ("x86/cpu/amd: Add a Zenbleed fix") That cause no changes to tooling: $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after $ diff -u before after $ Just silences this perf build warning: Warning: Kernel ABI header differences: diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/lkml/ZND17H7BI4ariERn@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 
To pick up the changes from these csets:

  522b1d69219d8f08 ("x86/cpu/amd: Add a Zenbleed fix")

That cause no changes to tooling:

  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before
  $ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after
  $ diff -u before after
  $

Just silences this perf build warning:

  Warning: Kernel ABI header differences:
    diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZND17H7BI4ariERn@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
x86/bugs: Increase the x86 bugs vector size to two u32s 2023-07-18T07:35:38+00:00 Borislav Petkov (AMD) bp@alien8.de 2023-07-08T08:21:35+00:00 0e52740ffd10c6c316837c6c128f460f1aaba1ea There was never a doubt in my mind that they would not fit into a single u32 eventually. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> 
There was never a doubt in my mind that they would not fit into a single
u32 eventually.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Merge tag 'x86_alternatives_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2023-06-26T22:14:55+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-06-26T22:14:55+00:00 8c69e7afe9588f9259a6422c6619d7643c76d12c Pull x86 instruction alternatives updates from Borislav Petkov: - Up until now the Fast Short Rep Mov optimizations implied the presence of the ERMS CPUID flag. AMD decoupled them with a BIOS setting so decouple that dependency in the kernel code too - Teach the alternatives machinery to handle relocations - Make debug_alternative accept flags in order to see only that set of patching done one is interested in - Other fixes, cleanups and optimizations to the patching code * tag 'x86_alternatives_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/alternative: PAUSE is not a NOP x86/alternatives: Add cond_resched() to text_poke_bp_batch() x86/nospec: Shorten RESET_CALL_DEPTH x86/alternatives: Add longer 64-bit NOPs x86/alternatives: Fix section mismatch warnings x86/alternative: Optimize returns patching x86/alternative: Complicate optimize_nops() some more x86/alternative: Rewrite optimize_nops() some x86/lib/memmove: Decouple ERMS from FSRM x86/alternative: Support relocations in alternatives x86/alternative: Make debug-alternative selective 
Pull x86 instruction alternatives updates from Borislav Petkov:

 - Up until now the Fast Short Rep Mov optimizations implied the
   presence of the ERMS CPUID flag. AMD decoupled them with a BIOS
   setting so decouple that dependency in the kernel code too

 - Teach the alternatives machinery to handle relocations

 - Make debug_alternative accept flags in order to see only that set of
   patching done one is interested in

 - Other fixes, cleanups and optimizations to the patching code

* tag 'x86_alternatives_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/alternative: PAUSE is not a NOP
  x86/alternatives: Add cond_resched() to text_poke_bp_batch()
  x86/nospec: Shorten RESET_CALL_DEPTH
  x86/alternatives: Add longer 64-bit NOPs
  x86/alternatives: Fix section mismatch warnings
  x86/alternative: Optimize returns patching
  x86/alternative: Complicate optimize_nops() some more
  x86/alternative: Rewrite optimize_nops() some
  x86/lib/memmove: Decouple ERMS from FSRM
  x86/alternative: Support relocations in alternatives
  x86/alternative: Make debug-alternative selective
x86/alternatives: Add longer 64-bit NOPs 2023-05-31T08:21:21+00:00 Peter Zijlstra peterz@infradead.org 2023-05-15T09:28:05+00:00 df25edbac31ea87b488789d44a362063542b5967 By adding support for longer NOPs there are a few more alternatives that can turn into a single instruction. Add up to NOP11, the same limit where GNU as .nops also stops generating longer nops. This is because a number of uarchs have severe decode penalties for more than 3 prefixes. [ bp: Sync up with the version in tools/ while at it. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20230515093020.661756940@infradead.org 
By adding support for longer NOPs there are a few more alternatives
that can turn into a single instruction.

Add up to NOP11, the same limit where GNU as .nops also stops
generating longer nops. This is because a number of uarchs have severe
decode penalties for more than 3 prefixes.

  [ bp: Sync up with the version in tools/ while at it. ]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230515093020.661756940@infradead.org
tools headers disabled-features: Sync with the kernel sources 2023-05-17T14:49:47+00:00 Arnaldo Carvalho de Melo acme@redhat.com 2023-05-17T14:47:38+00:00 1b5f159ce8751b61aea426293cd71a510a081939 To pick the changes from: e0bddc19ba9578bc ("x86/mm: Reduce untagged_addr() overhead for systems without LAM") This only causes these perf files to be rebuilt: CC /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o CC /tmp/build/perf/bench/mem-memset-x86-64-asm.o And addresses this perf build warning: Warning: Kernel ABI header at 'tools/arch/x86/include/asm/disabled-features.h' differs from latest version at 'arch/x86/include/asm/disabled-features.h' diff -u tools/arch/x86/include/asm/disabled-features.h arch/x86/include/asm/disabled-features.h Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/lkml/ZGTpdlzrlRjjnY6K@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 
To pick the changes from:

  e0bddc19ba9578bc ("x86/mm: Reduce untagged_addr() overhead for systems without LAM")

This only causes these perf files to be rebuilt:

  CC       /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
  CC       /tmp/build/perf/bench/mem-memset-x86-64-asm.o

And addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/disabled-features.h' differs from latest version at 'arch/x86/include/asm/disabled-features.h'
  diff -u tools/arch/x86/include/asm/disabled-features.h arch/x86/include/asm/disabled-features.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZGTpdlzrlRjjnY6K@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools headers x86 cpufeatures: Sync with the kernel sources 2023-05-17T13:39:40+00:00 Arnaldo Carvalho de Melo acme@redhat.com 2023-05-17T13:10:57+00:00 9bc83d6e3824f09cef73b01256962d950965ddc4 To pick the changes from: 3d8f61bf8bcd69bc ("x86: KVM: Add common feature flag for AMD's PSFD") 3763bf58029f3459 ("x86/cpufeatures: Redefine synthetic virtual NMI bit as AMD's "real" vNMI") 6449dcb0cac73821 ("x86: CPUID and CR3/CR4 flags for Linear Address Masking") be8de49bea505e77 ("x86/speculation: Identify processors vulnerable to SMT RSB predictions") e7862eda309ecfcc ("x86/cpu: Support AMD Automatic IBRS") faabfcb194a8d068 ("x86/cpu, kvm: Add the SMM_CTL MSR not present feature") 5b909d4ae59aedc7 ("x86/cpu, kvm: Add the Null Selector Clears Base feature") 84168ae786f8a15a ("x86/cpu, kvm: Move X86_FEATURE_LFENCE_RDTSC to its native leaf") a9dc9ec5a1fafc3d ("x86/cpu, kvm: Add the NO_NESTED_DATA_BP feature") f8df91e73a6827a4 ("x86/cpufeatures: Add macros for Intel's new fast rep string features") 78335aac6156eada ("x86/cpufeatures: Add Bandwidth Monitoring Event Configuration feature flag") f334f723a63cfc25 ("x86/cpufeatures: Add Slow Memory Bandwidth Allocation feature flag") a018d2e3d4b1abc4 ("x86/cpufeatures: Add Architectural PerfMon Extension bit") This causes these perf files to be rebuilt and brings some X86_FEATURE that will be used when updating the copies of tools/arch/x86/lib/mem{cpy,set}_64.S with the kernel sources: CC /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o CC /tmp/build/perf/bench/mem-memset-x86-64-asm.o And addresses this perf build warning: Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h' diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Kim Phillips <kim.phillips@amd.com> Cc: Jim Mattson <jmattson@google.com> Cc: Babu Moger <babu.moger@amd.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/lkml/ZGTTw642q8mWgv2Y@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 
To pick the changes from:

  3d8f61bf8bcd69bc ("x86: KVM: Add common feature flag for AMD's PSFD")
  3763bf58029f3459 ("x86/cpufeatures: Redefine synthetic virtual NMI bit as AMD's "real" vNMI")
  6449dcb0cac73821 ("x86: CPUID and CR3/CR4 flags for Linear Address Masking")
  be8de49bea505e77 ("x86/speculation: Identify processors vulnerable to SMT RSB predictions")
  e7862eda309ecfcc ("x86/cpu: Support AMD Automatic IBRS")
  faabfcb194a8d068 ("x86/cpu, kvm: Add the SMM_CTL MSR not present feature")
  5b909d4ae59aedc7 ("x86/cpu, kvm: Add the Null Selector Clears Base feature")
  84168ae786f8a15a ("x86/cpu, kvm: Move X86_FEATURE_LFENCE_RDTSC to its native leaf")
  a9dc9ec5a1fafc3d ("x86/cpu, kvm: Add the NO_NESTED_DATA_BP feature")
  f8df91e73a6827a4 ("x86/cpufeatures: Add macros for Intel's new fast rep string features")
  78335aac6156eada ("x86/cpufeatures: Add Bandwidth Monitoring Event Configuration feature flag")
  f334f723a63cfc25 ("x86/cpufeatures: Add Slow Memory Bandwidth Allocation feature flag")
  a018d2e3d4b1abc4 ("x86/cpufeatures: Add Architectural PerfMon Extension bit")

This causes these perf files to be rebuilt and brings some X86_FEATURE
that will be used when updating the copies of
tools/arch/x86/lib/mem{cpy,set}_64.S with the kernel sources:

  CC       /tmp/build/perf/bench/mem-memcpy-x86-64-asm.o
  CC       /tmp/build/perf/bench/mem-memset-x86-64-asm.o

And addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/cpufeatures.h' differs from latest version at 'arch/x86/include/asm/cpufeatures.h'
  diff -u tools/arch/x86/include/asm/cpufeatures.h arch/x86/include/asm/cpufeatures.h

Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Babu Moger <babu.moger@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/lkml/ZGTTw642q8mWgv2Y@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools arch x86: Sync the msr-index.h copy with the kernel sources 2023-05-10T17:19:20+00:00 Yanteng Si siyanteng@loongson.cn 2023-05-10T10:24:52+00:00 34e82891d995ab89b494032c5ab0ee939cbb7524 Picking the changes from: c68e3d473988b9af ("x86/include/asm/msr-index.h: Add IFS Array test bits") Silencing these perf build warnings: Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h' diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: loongson-kernel@lists.loongnix.cn Link: https://lore.kernel.org/r/05778ab3c168c8030f6b20e60375dc803f0cd300.1683712945.git.siyanteng@loongson.cn Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 
Picking the changes from:

  c68e3d473988b9af ("x86/include/asm/msr-index.h: Add IFS Array test bits")

Silencing these perf build warnings:

  Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'
  diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h

Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: loongson-kernel@lists.loongnix.cn
Link: https://lore.kernel.org/r/05778ab3c168c8030f6b20e60375dc803f0cd300.1683712945.git.siyanteng@loongson.cn
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Merge tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2023-04-28T21:02:54+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-04-28T21:02:54+00:00 2aff7c706c7483f4895ca250c92c1d71e45b6e82 Pull objtool updates from Ingo Molnar: - Mark arch_cpu_idle_dead() __noreturn, make all architectures & drivers that did this inconsistently follow this new, common convention, and fix all the fallout that objtool can now detect statically - Fix/improve the ORC unwinder becoming unreliable due to UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED to resolve it - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code - Generate ORC data for __pfx code - Add more __noreturn annotations to various kernel startup/shutdown and panic functions - Misc improvements & fixes * tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/hyperv: Mark hv_ghcb_terminate() as noreturn scsi: message: fusion: Mark mpt_halt_firmware() __noreturn x86/cpu: Mark {hlt,resume}_play_dead() __noreturn btrfs: Mark btrfs_assertfail() __noreturn objtool: Include weak functions in global_noreturns check cpu: Mark nmi_panic_self_stop() __noreturn cpu: Mark panic_smp_self_stop() __noreturn arm64/cpu: Mark cpu_park_loop() and friends __noreturn x86/head: Mark *_start_kernel() __noreturn init: Mark start_kernel() __noreturn init: Mark [arch_call_]rest_init() __noreturn objtool: Generate ORC data for __pfx code x86/linkage: Fix padding for typed functions objtool: Separate prefix code from stack validation code objtool: Remove superfluous dead_end_function() check objtool: Add symbol iteration helpers objtool: Add WARN_INSN() scripts/objdump-func: Support multiple functions context_tracking: Fix KCSAN noinstr violation objtool: Add stackleak instrumentation to uaccess safe list ... 
Pull objtool updates from Ingo Molnar:

 - Mark arch_cpu_idle_dead() __noreturn, make all architectures &
   drivers that did this inconsistently follow this new, common
   convention, and fix all the fallout that objtool can now detect
   statically

 - Fix/improve the ORC unwinder becoming unreliable due to
   UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK
   and UNWIND_HINT_UNDEFINED to resolve it

 - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code

 - Generate ORC data for __pfx code

 - Add more __noreturn annotations to various kernel startup/shutdown
   and panic functions

 - Misc improvements & fixes

* tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  x86/hyperv: Mark hv_ghcb_terminate() as noreturn
  scsi: message: fusion: Mark mpt_halt_firmware() __noreturn
  x86/cpu: Mark {hlt,resume}_play_dead() __noreturn
  btrfs: Mark btrfs_assertfail() __noreturn
  objtool: Include weak functions in global_noreturns check
  cpu: Mark nmi_panic_self_stop() __noreturn
  cpu: Mark panic_smp_self_stop() __noreturn
  arm64/cpu: Mark cpu_park_loop() and friends __noreturn
  x86/head: Mark *_start_kernel() __noreturn
  init: Mark start_kernel() __noreturn
  init: Mark [arch_call_]rest_init() __noreturn
  objtool: Generate ORC data for __pfx code
  x86/linkage: Fix padding for typed functions
  objtool: Separate prefix code from stack validation code
  objtool: Remove superfluous dead_end_function() check
  objtool: Add symbol iteration helpers
  objtool: Add WARN_INSN()
  scripts/objdump-func: Support multiple functions
  context_tracking: Fix KCSAN noinstr violation
  objtool: Add stackleak instrumentation to uaccess safe list
  ...
x86,objtool: Split UNWIND_HINT_EMPTY in two 2023-03-23T22:18:58+00:00 Josh Poimboeuf jpoimboe@kernel.org 2023-03-01T15:13:12+00:00 fb799447ae2974a07907906dff5bd4b9e47b7123 Mark reported that the ORC unwinder incorrectly marks an unwind as reliable when the unwind terminates prematurely in the dark corners of return_to_handler() due to lack of information about the next frame. The problem is UNWIND_HINT_EMPTY is used in two different situations: 1) The end of the kernel stack unwind before hitting user entry, boot code, or fork entry 2) A blind spot in ORC coverage where the unwinder has to bail due to lack of information about the next frame The ORC unwinder has no way to tell the difference between the two. When it encounters an undefined stack state with 'end=1', it blindly marks the stack reliable, which can break the livepatch consistency model. Fix it by splitting UNWIND_HINT_EMPTY into UNWIND_HINT_UNDEFINED and UNWIND_HINT_END_OF_STACK. Reported-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/fd6212c8b450d3564b855e1cb48404d6277b4d9f.1677683419.git.jpoimboe@kernel.org 
Mark reported that the ORC unwinder incorrectly marks an unwind as
reliable when the unwind terminates prematurely in the dark corners of
return_to_handler() due to lack of information about the next frame.

The problem is UNWIND_HINT_EMPTY is used in two different situations:

  1) The end of the kernel stack unwind before hitting user entry, boot
     code, or fork entry

  2) A blind spot in ORC coverage where the unwinder has to bail due to
     lack of information about the next frame

The ORC unwinder has no way to tell the difference between the two.
When it encounters an undefined stack state with 'end=1', it blindly
marks the stack reliable, which can break the livepatch consistency
model.

Fix it by splitting UNWIND_HINT_EMPTY into UNWIND_HINT_UNDEFINED and
UNWIND_HINT_END_OF_STACK.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/fd6212c8b450d3564b855e1cb48404d6277b4d9f.1677683419.git.jpoimboe@kernel.org