kernel/linux.git/tools/arch/x86/include, branch v6.1.168

work around gcc bugs with 'asm goto' with outputs

2024-02-23T08:12:28+00:00

commit 68fb3ca0e408e00db1c3f8fccdfa19e274c033be upstream. We've had issues with gcc and 'asm goto' before, and we created a 'asm_volatile_goto()' macro for that in the past: see commits 3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation bug") and a9f180345f53 ("compiler/gcc4: Make quirk for asm_volatile_goto() unconditional"). Then, much later, we ended up removing the workaround in commit 43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR 58670") because we no longer supported building the kernel with the affected gcc versions, but we left the macro uses around. Now, Sean Christopherson reports a new version of a very similar problem, which is fixed by re-applying that ancient workaround. But the problem in question is limited to only the 'asm goto with outputs' cases, so instead of re-introducing the old workaround as-is, let's rename and limit the workaround to just that much less common case. It looks like there are at least two separate issues that all hit in this area: (a) some versions of gcc don't mark the asm goto as 'volatile' when it has outputs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 which is easy to work around by just adding the 'volatile' by hand. (b) Internal compiler errors: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 which are worked around by adding the extra empty 'asm' as a barrier, as in the original workaround. but the problem Sean sees may be a third thing since it involves bad code generation (not an ICE) even with the manually added 'volatile'. The same old workaround works for this case, even if this feels a bit like voodoo programming and may only be hiding the issue. Reported-and-tested-by: Sean Christopherson Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Cc: Nick Desaulniers Cc: Uros Bizjak Cc: Jakub Jelinek Cc: Andrew Pinski Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

x86/bugs: Increase the x86 bugs vector size to two u32s

2023-08-08T18:03:50+00:00

Upstream commit: 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) Signed-off-by: Greg Kroah-Hartman

x86/cpu: Restore AMD's DE_CFG MSR after resume

2022-11-15T18:15:58+00:00

DE_CFG contains the LFENCE serializing bit, restore it on resume too. This is relevant to older families due to the way how they do S3. Unify and correct naming while at it. Fixes: e4d0e84e4907 ("x86/cpu/AMD: Make LFENCE a serializing instruction") Reported-by: Andrew Cooper Reported-by: Pawan Gupta Signed-off-by: Borislav Petkov Cc: Signed-off-by: Linus Torvalds

tools headers cpufeatures: Sync with the kernel sources

2022-10-25T20:40:48+00:00

To pick the changes from: 257449c6a50298bd ("x86/cpufeatures: Add LbrExtV2 feature bit") 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/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: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sandipan Das Link: https://lore.kernel.org/lkml/Y1g6vGPqPhOrXoaN@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools arch x86: Sync the msr-index.h copy with the kernel sources

2022-10-15T13:13:16+00:00

To pick up the changes in: b8d1d163604bd1e6 ("x86/apic: Don't disable x2APIC if locked") ca5b7c0d9621702e ("perf/x86/amd/lbr: Add LbrExtV2 branch record support") Addressing these tools/perf build warnings: diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h 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' That makes the beautification scripts to pick some new entries: $ 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 --- before 2022-10-14 18:06:34.294561729 -0300 +++ after 2022-10-14 18:06:41.285744044 -0300 @@ -264,6 +264,7 @@ [0xc0000102 - x86_64_specific_MSRs_offset] = "KERNEL_GS_BASE", [0xc0000103 - x86_64_specific_MSRs_offset] = "TSC_AUX", [0xc0000104 - x86_64_specific_MSRs_offset] = "AMD64_TSC_RATIO", + [0xc000010e - x86_64_specific_MSRs_offset] = "AMD64_LBR_SELECT", [0xc000010f - x86_64_specific_MSRs_offset] = "AMD_DBG_EXTN_CFG", [0xc0000300 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_STATUS", [0xc0000301 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_CTL", $ Now one can trace systemwide asking to see backtraces to where that MSR is being read/written, see this example with a previous update: # perf trace -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB" ^C# If we use -v (verbose mode) we can see what it does behind the scenes: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB" Using CPUID AuthenticAMD-25-21-0 0x6a0 0x6a8 New filter for msr:read_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313) 0x6a0 0x6a8 New filter for msr:write_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313) mmap size 528384B ^C# Example with a frequent msr: # perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_SPEC_CTRL" --max-events 2 Using CPUID AuthenticAMD-25-21-0 0x48 New filter for msr:read_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841) 0x48 New filter for msr:write_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841) mmap size 528384B Looking at the vmlinux_path (8 entries long) symsrc__init: build id mismatch for vmlinux. Using /proc/kcore for kernel data Using /proc/kallsyms for symbols 0.000 Timer/2525383 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule ([kernel.kallsyms]) futex_wait_queue_me ([kernel.kallsyms]) futex_wait ([kernel.kallsyms]) do_futex ([kernel.kallsyms]) __x64_sys_futex ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __futex_abstimed_wait_common64 (/usr/lib64/libpthread-2.33.so) 0.030 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL, val: 2) do_trace_write_msr ([kernel.kallsyms]) do_trace_write_msr ([kernel.kallsyms]) __switch_to_xtra ([kernel.kallsyms]) __switch_to ([kernel.kallsyms]) __schedule ([kernel.kallsyms]) schedule_idle ([kernel.kallsyms]) do_idle ([kernel.kallsyms]) cpu_startup_entry ([kernel.kallsyms]) secondary_startup_64_no_verify ([kernel.kallsyms]) # Cc: Adrian Hunter Cc: Daniel Sneddon Cc: Dave Hansen Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sandipan Das Link: https://lore.kernel.org/lkml/Y0nQkz2TUJxwfXJd@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf amd ibs: Sync arch/x86/include/asm/amd-ibs.h header with the kernel

2022-10-06T19:27:38+00:00

Although new details added into this header is currently used by kernel only, tools copy needs to be in sync with kernel file to avoid tools/perf/check-headers.sh warnings. Signed-off-by: Ravi Bangoria Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Ali Saidi Cc: Ananth Narayan Cc: Andi Kleen Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Ian Rogers Cc: Ingo Molnar Cc: Joe Mario Cc: Kan Liang Cc: Kim Phillips Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sandipan Das Cc: Santosh Shukla Cc: Stephane Eranian Cc: Thomas Gleixner Cc: x86@kernel.org Link: https://lore.kernel.org/r/20221006153946.7816-3-ravi.bangoria@amd.com Signed-off-by: Arnaldo Carvalho de Melo

tools headers cpufeatures: Sync with the kernel sources

2022-09-21T19:08:00+00:00

To pick the changes from: 7df548840c496b01 ("x86/bugs: Add "unknown" reporting for MMIO Stale Data") 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/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: Adrian Hunter Cc: Borislav Petkov Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Pawan Gupta Link: https://lore.kernel.org/lkml/YysTRji90sNn2p5f@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

asm goto: eradicate CC_HAS_ASM_GOTO

2022-08-21T17:06:28+00:00

GCC has supported asm goto since 4.5, and Clang has since version 9.0.0. The minimum supported versions of these tools for the build according to Documentation/process/changes.rst are 5.1 and 11.0.0 respectively. Remove the feature detection script, Kconfig option, and clean up some fallback code that is no longer supported. The removed script was also testing for a GCC specific bug that was fixed in the 4.7 release. Also remove workarounds for bpftrace using clang older than 9.0.0, since other BPF backend fixes are required at this point. Link: https://lore.kernel.org/lkml/CAK7LNATSr=BXKfkdW8f-H5VT_w=xBpT2ZQcZ7rm6JfkdE+QnmA@mail.gmail.com/ Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 Acked-by: Borislav Petkov Suggested-by: Masahiro Yamada Suggested-by: Alexei Starovoitov Signed-off-by: Nick Desaulniers Reviewed-by: Ingo Molnar Reviewed-by: Nathan Chancellor Reviewed-by: Alexandre Belloni Signed-off-by: Linus Torvalds

tools headers UAPI: Sync x86's asm/kvm.h with the kernel sources

2022-08-19T18:30:34+00:00

To pick the changes in: 43bb9e000ea4c621 ("KVM: x86: Tweak name of MONITOR/MWAIT #UD quirk to make it #UD specific") 94dfc73e7cf4a31d ("treewide: uapi: Replace zero-length arrays with flexible-array members") bfbcc81bb82cbbad ("KVM: x86: Add a quirk for KVM's "MONITOR/MWAIT are NOPs!" behavior") b172862241b48499 ("KVM: x86: PIT: Preserve state of speaker port data bit") ed2351174e38ad4f ("KVM: x86: Extend KVM_{G,S}ET_VCPU_EVENTS to support pending triple fault") That just rebuilds kvm-stat.c on x86, no change in functionality. This silences these perf build warning: Warning: Kernel ABI header at 'tools/arch/x86/include/uapi/asm/kvm.h' differs from latest version at 'arch/x86/include/uapi/asm/kvm.h' diff -u tools/arch/x86/include/uapi/asm/kvm.h arch/x86/include/uapi/asm/kvm.h Cc: Chenyi Qiang Cc: Sean Christopherson Cc: Gustavo A. R. Silva Cc: Paolo Bonzini Cc: Paul Durrant Link: https://lore.kernel.org/lkml/Yv6OMPKYqYSbUxwZ@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools headers UAPI: Sync KVM's vmx.h header with the kernel sources

2022-08-19T18:30:34+00:00

To pick the changes in: 2f4073e08f4cc5a4 ("KVM: VMX: Enable Notify VM exit") That makes 'perf kvm-stat' aware of this new NOTIFY exit reason, thus addressing the following perf build warning: Warning: Kernel ABI header at 'tools/arch/x86/include/uapi/asm/vmx.h' differs from latest version at 'arch/x86/include/uapi/asm/vmx.h' diff -u tools/arch/x86/include/uapi/asm/vmx.h arch/x86/include/uapi/asm/vmx.h Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paolo Bonzini Cc: Tao Xu Link: http://lore.kernel.org/lkml/Yv6LavXMZ+njijpq@kernel.org Signed-off-by: Arnaldo Carvalho de Melo