Re: [PATCH] perf parse-events: Use uintptr_t when casting numbers to pointers

[Arnaldo Carvalho de Melo]

Em Thu, Sep 03, 2020 at 10:31:09PM -0700, Ian Rogers escreveu:
> On Thu, Sep 3, 2020 at 11:44 AM Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
> >         Please check that this is ok with you,
> 
> Thanks Arnaldo, this looks good to me!

Thanks for checkint!

- Arnaldo

> There is a separate issue, the casts are necessary as we have
> PE_VALUEs that are supposed to be numbers but here are list*. It seems
> error prone to have something that is a pointer or a number, and so I
> wonder if we can introduce new tokens in parse-events.y to handle
> this. It'd also mean that yydestructors and the like could clean up
> error states. I'll try to take a look.
 
> Thanks,
> Ian
> 
> > commit 0823f768b800cca2592fad3b5649766ae6bc4eba
> > Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > Date:   Thu Sep 3 15:34:20 2020 -0300
> >
> >     perf parse-events: Use uintptr_t when casting numbers to pointers
> >
> >     To address these errors found when cross building from x86_64 to MIPS
> >     little endian 32-bit:
> >
> >         CC       /tmp/build/perf/util/parse-events-bison.o
> >       util/parse-events.y: In function 'parse_events_parse':
> >       util/parse-events.y:514:6: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
> >         514 |      (void *) $2, $6, $4);
> >             |      ^
> >       util/parse-events.y:531:7: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
> >         531 |       (void *) $2, NULL, $4)) {
> >             |       ^
> >       util/parse-events.y:547:6: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
> >         547 |      (void *) $2, $4, 0);
> >             |      ^
> >       util/parse-events.y:564:7: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
> >         564 |       (void *) $2, NULL, 0)) {
> >             |       ^
> >
> >     Fixes: cabbf26821aa210f ("perf parse: Before yyabort-ing free components")
> >     Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> >     Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
> >     Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
> >     Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> >     Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> >     Cc: Ian Rogers <irogers@xxxxxxxxxx>
> >     Cc: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> >     Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> >     Cc: John Garry <john.garry@xxxxxxxxxx>
> >     Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
> >     Cc: Mark Rutland <mark.rutland@xxxxxxx>
> >     Cc: Martin KaFai Lau <kafai@xxxxxx>
> >     Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> >     Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> >     Cc: Song Liu <songliubraving@xxxxxx>
> >     Cc: Stephane Eranian <eranian@xxxxxxxxxx>
> >     Cc: Yonghong Song <yhs@xxxxxx>
> >     Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> >
> > diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> > index b9fb91fdc5de9177..645bf4f1859fd76b 100644
> > --- a/tools/perf/util/parse-events.y
> > +++ b/tools/perf/util/parse-events.y
> > @@ -511,7 +511,7 @@ PE_PREFIX_MEM PE_VALUE '/' PE_VALUE ':' PE_MODIFIER_BP sep_dc
> >         list = alloc_list();
> >         ABORT_ON(!list);
> >         err = parse_events_add_breakpoint(list, &parse_state->idx,
> > -                                       (void *) $2, $6, $4);
> > +                                       (void *)(uintptr_t) $2, $6, $4);
> >         free($6);
> >         if (err) {
> >                 free(list);
> > @@ -528,7 +528,7 @@ PE_PREFIX_MEM PE_VALUE '/' PE_VALUE sep_dc
> >         list = alloc_list();
> >         ABORT_ON(!list);
> >         if (parse_events_add_breakpoint(list, &parse_state->idx,
> > -                                               (void *) $2, NULL, $4)) {
> > +                                               (void *)(uintptr_t) $2, NULL, $4)) {
> >                 free(list);
> >                 YYABORT;
> >         }
> > @@ -544,7 +544,7 @@ PE_PREFIX_MEM PE_VALUE ':' PE_MODIFIER_BP sep_dc
> >         list = alloc_list();
> >         ABORT_ON(!list);
> >         err = parse_events_add_breakpoint(list, &parse_state->idx,
> > -                                       (void *) $2, $4, 0);
> > +                                       (void *)(uintptr_t) $2, $4, 0);
> >         free($4);
> >         if (err) {
> >                 free(list);
> > @@ -561,7 +561,7 @@ PE_PREFIX_MEM PE_VALUE sep_dc
> >         list = alloc_list();
> >         ABORT_ON(!list);
> >         if (parse_events_add_breakpoint(list, &parse_state->idx,
> > -                                               (void *) $2, NULL, 0)) {
> > +                                               (void *)(uintptr_t) $2, NULL, 0)) {
> >                 free(list);
> >                 YYABORT;
> >         }

-- 

- Arnaldo