Re: [PATCH 1/2] perf alsr: Add missing SIMD handling in aslr_tool__process_sample()

[Ian Rogers]

On Sun, Sep 20, 2026 at 11:42 PM Mi, Dapeng <dapeng1.mi@xxxxxxxxxxxxxxx> wrote:
>
> Kindly ping ...
>
> @Arnaldo, @Namhyung, @Ian, not sure if you have bandwidth to review this
> small patchset which fixes the Sashiko found minor issues for the "Perf
> tools: Support eGPRs/SSP/SIMD registers sampling" patchset?
>
> If possible, it's better to be queued in this cycle, then we don't need
> extra backporting. Thanks.

Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

> On 9/15/2026 5:11 PM, Dapeng Mi wrote:
> > Currently the SIMD register sampling is supported, but the corresponding
> > handling is missed in aslr_tool__process_sample(). This can break parsing
> > of the sample record.
> >
> > Add the missing SIMD register handling in aslr_tool__process_sample().
> >
> > Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
> > ---
> >
> > These two patches fix Sashiko reported defects for the patchset:
> > "Perf tools: Support eGPRs/SSP/SIMD registers sampling"
> > https://lore.kernel.org/all/20260914014049.2061519-1-dapeng1.mi@xxxxxxxxxxxxxxx/
> >
> >  tools/perf/util/aslr.c | 31 +++++++++++++++++++++++++++++++
> >  1 file changed, 31 insertions(+)
> >
> > diff --git a/tools/perf/util/aslr.c b/tools/perf/util/aslr.c
> > index 027695d96779..a097084201a0 100644
> > --- a/tools/perf/util/aslr.c
> > +++ b/tools/perf/util/aslr.c
> > @@ -19,6 +19,7 @@
> >  #include <internal/lib.h>  /* page_size */
> >  #include <linux/compiler.h>
> >  #include <linux/zalloc.h>
> > +#include <linux/overflow.h>
> >  #include <errno.h>
> >  #include <inttypes.h>
> >  #include <unistd.h>
> > @@ -992,6 +993,34 @@ static int aslr_tool__process_sample(const struct perf_tool *tool,
> >                               COPY_U64();
> >               }
> >       }
> > +
> > +#define CHECK_SIMD() \
> > +     do { \
> > +             if (abi & PERF_SAMPLE_REGS_ABI_SIMD) { \
> > +                     u64 nr_vector, vec_qwords; \
> > +                     u64 nr_pred, pred_qwords; \
> > +                     u64 header_len, vec_len, pred_len, simd_len; \
> > +                     if (CHECK_BOUNDS(nr + 4, nr + 4)) { \
> > +                             ret = -EFAULT; \
> > +                             goto out_put; \
> > +                     } \
> > +                     header_len = 4; \
> > +                     nr_vector = in_array[i + nr]; \
> > +                     vec_qwords = in_array[i + nr + 1]; \
> > +                     nr_pred = in_array[i + nr + 2]; \
> > +                     pred_qwords = in_array[i + nr + 3]; \
> > +                     if (check_mul_overflow(nr_vector, vec_qwords, &vec_len) || \
> > +                         check_mul_overflow(nr_pred, pred_qwords, &pred_len) || \
> > +                         check_add_overflow(vec_len, pred_len, &simd_len) || \
> > +                         check_add_overflow(header_len, simd_len, &simd_len) || \
> > +                         check_add_overflow(nr, simd_len, &nr) || \
> > +                         nr > max_i - i) { \
> > +                             ret = -EFAULT; \
> > +                             goto out_put; \
> > +                     } \
> > +             } \
> > +     } while (0)
> > +
> >       if (orig_sample_type & PERF_SAMPLE_REGS_USER) {
> >               u64 abi;
> >
> > @@ -1007,6 +1036,7 @@ static int aslr_tool__process_sample(const struct perf_tool *tool,
> >                               ret = -EFAULT;
> >                               goto out_put;
> >                       }
> > +                     CHECK_SIMD();
> >                       i += nr;
> >               }
> >       }
> > @@ -1061,6 +1091,7 @@ static int aslr_tool__process_sample(const struct perf_tool *tool,
> >                               ret = -EFAULT;
> >                               goto out_put;
> >                       }
> > +                     CHECK_SIMD();

nit: at the end of the function you could #undef CHECK_SIMD to make it
more explicit that the macro only makes sense within the function.

Thanks,
Ian

> >                       i += nr;
> >               }
> >       }
> >
> > base-commit: 91b0782fc9e9d2f0a40b5256146e014802fdbb36