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

tools/x86/kcpuid: Protect against faulty "max subleaf" values

2024-10-17T13:21:41+00:00

[ Upstream commit cf96ab1a966b87b09fdd9e8cc8357d2d00776a3a ] Protect against the kcpuid code parsing faulty max subleaf numbers through a min() expression. Thus, ensuring that max_subleaf will always be ≤ MAX_SUBLEAF_NUM. Use "u32" for the subleaf numbers since kcpuid is compiled with -Wextra, which includes signed/unsigned comparisons warnings. Signed-off-by: Ahmed S. Darwish Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20240718134755.378115-5-darwi@linutronix.de Signed-off-by: Sasha Levin

x86/insn: Add VEX versions of VPDPBUSD, VPDPBUSDS, VPDPWSSD and VPDPWSSDS

2024-06-12T09:03:30+00:00

[ Upstream commit b8000264348979b60dbe479255570a40e1b3a097 ] The x86 instruction decoder is used not only for decoding kernel instructions. It is also used by perf uprobes (user space probes) and by perf tools Intel Processor Trace decoding. Consequently, it needs to support instructions executed by user space also. Intel Architecture Instruction Set Extensions and Future Features manual number 319433-044 of May 2021, documented VEX versions of instructions VPDPBUSD, VPDPBUSDS, VPDPWSSD and VPDPWSSDS, but the opcode map has them listed as EVEX only. Remove EVEX-only (ev) annotation from instructions VPDPBUSD, VPDPBUSDS, VPDPWSSD and VPDPWSSDS, which allows them to be decoded with either a VEX or EVEX prefix. Fixes: 0153d98f2dd6 ("x86/insn: Add misc instructions to x86 instruction decoder") Signed-off-by: Adrian Hunter Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20240502105853.5338-4-adrian.hunter@intel.com Signed-off-by: Sasha Levin

x86/insn: Fix PUSH instruction in x86 instruction decoder opcode map

2024-06-12T09:03:30+00:00

[ Upstream commit 59162e0c11d7257cde15f907d19fefe26da66692 ] The x86 instruction decoder is used not only for decoding kernel instructions. It is also used by perf uprobes (user space probes) and by perf tools Intel Processor Trace decoding. Consequently, it needs to support instructions executed by user space also. Opcode 0x68 PUSH instruction is currently defined as 64-bit operand size only i.e. (d64). That was based on Intel SDM Opcode Map. However that is contradicted by the Instruction Set Reference section for PUSH in the same manual. Remove 64-bit operand size only annotation from opcode 0x68 PUSH instruction. Example: $ cat pushw.s .global _start .text _start: pushw $0x1234 mov $0x1,%eax # system call number (sys_exit) int $0x80 $ as -o pushw.o pushw.s $ ld -s -o pushw pushw.o $ objdump -d pushw | tail -4 0000000000401000 <.text>: 401000: 66 68 34 12 pushw $0x1234 401004: b8 01 00 00 00 mov $0x1,%eax 401009: cd 80 int $0x80 $ perf record -e intel_pt//u ./pushw [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.014 MB perf.data ] Before: $ perf script --insn-trace=disasm Warning: 1 instruction trace errors pushw 10349 [000] 10586.869237014: 401000 [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) pushw $0x1234 pushw 10349 [000] 10586.869237014: 401006 [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) addb %al, (%rax) pushw 10349 [000] 10586.869237014: 401008 [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) addb %cl, %ch pushw 10349 [000] 10586.869237014: 40100a [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) addb $0x2e, (%rax) instruction trace error type 1 time 10586.869237224 cpu 0 pid 10349 tid 10349 ip 0x40100d code 6: Trace doesn't match instruction After: $ perf script --insn-trace=disasm pushw 10349 [000] 10586.869237014: 401000 [unknown] (./pushw) pushw $0x1234 pushw 10349 [000] 10586.869237014: 401004 [unknown] (./pushw) movl $1, %eax Fixes: eb13296cfaf6 ("x86: Instruction decoder API") Signed-off-by: Adrian Hunter Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20240502105853.5338-3-adrian.hunter@intel.com Signed-off-by: Sasha Levin

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

tools/x86/kcpuid: Fix avx512bw and avx512lvl fields in Fn00000007

2023-05-11T14:03:07+00:00

[ Upstream commit 4e347bdf44c1fd4296a7b9657a2c0e1bd900fa50 ] Leaf Fn00000007 contains avx512bw at bit 26 and avx512vl at bit 28. This is incorrect per the SDM. Correct avx512bw to be bit 30 and avx512lvl to be bit 31. Fixes: c6b2f240bf8d ("tools/x86: Add a kcpuid tool to show raw CPU features") Signed-off-by: Terry Bowman Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Feng Tang Link: https://lore.kernel.org/r/20230206141832.4162264-2-terry.bowman@amd.com Signed-off-by: Sasha Levin

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 headers: Update the copy of x86's memcpy_64.S used in 'perf bench'

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

We also need to add SYM_TYPED_FUNC_START() to util/include/linux/linkage.h and update tools/perf/check_headers.sh to ignore the include cfi_types.h line when checking if the kernel original files drifted from the copies we carry. This is to get the changes from: ccace936eec7b805 ("x86: Add types to indirectly called assembly functions") Addressing these tools/perf build warnings: 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 Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Kees Cook Cc: Sami Tolvanen Link: https://lore.kernel.org/lkml/Y1f3VRIec9EBgX6F@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