Re: [Patch v10 10/10] perf tests: Add SIMD registers sampling test

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The test validation logic for SIMD register sampling uses a loose grep pattern that can falsely report success if a sampled symbol contains the register class name.
--

--- Patch [10]: [Patch v10 10/10] perf tests: Add SIMD registers sampling test ---
commit 1c34ec145d62a684219e4898c8fe2a820402bef2
Author: Dapeng Mi <dapeng1.mi@linux.intel.com>

perf tests: Add SIMD registers sampling test

Validate that SIMD registers (XMM/YMM/ZMM on x86) can be sampled
correctly with hardware support.

> diff --git a/tools/perf/tests/shell/record.sh b/tools/perf/tests/shell/record.sh
> index 3c17f68ceb929..4a8539a65fa86 100755
> --- a/tools/perf/tests/shell/record.sh
> +++ b/tools/perf/tests/shell/record.sh

[ ... ]

> @@ -252,6 +252,136 @@ test_egpr_register_capture() {

[ ... ]

> +validate_simd_sampling_mode() {
> +  local regs_opt="$1"
> +  local simd_classes="$2"
> +  local script_field="$3"
> +  local simd_class
> +  local sample_output
> +
> +  for simd_class in ${simd_classes}
> +  do
> +    if ! sample_output=$(perf record -o - "${regs_opt}=${simd_class}" \
> +      -e br_inst_retired.near_call -c 1000 --per-thread ${testprog} 2> /dev/null \
> +      | perf script -F ip,sym,"${script_field}" -i - 2> /dev/null)
> +    then
> +      echo "SIMD register capture test [Failed record ${regs_opt}=${simd_class}]"
> +      return 1
> +    fi
> +
> +    if ! has_required_regs "${sample_output}" "${simd_class}"

[Severity: Medium]
Will this search pattern mistakenly match symbol names instead of the actual
register dump?

When perf script outputs symbol names alongside the registers, passing the
raw class name without delimiters to has_required_regs might falsely match
C library routines like __memcmp_sse4_1_xmm or __memcpy_avx_unaligned_erms_ymm.

Could this check be made more strict, perhaps by including delimiters to
ensure it only matches the register dump data and not the sampled symbol
names?

> +    then
> +      echo "SIMD register capture test [Failed missing ${simd_class} sampling data]"
> +      return 1
> +    fi
> +  done
> +
> +  return 0
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260721072707.3787848-1-dapeng1.mi@linux.intel.com?part=10