Messages in this thread | | | From | Rob Herring <> | Date | Thu, 15 Apr 2021 15:02:48 -0500 | Subject | Re: [PATCH] libperf: xyarray: Add bounds checks to xyarray__entry() |
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On Thu, Apr 15, 2021 at 2:51 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > Em Thu, Apr 15, 2021 at 04:48:34PM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Thu, Apr 15, 2021 at 04:46:46PM -0300, Arnaldo Carvalho de Melo escreveu: > > > Em Wed, Apr 14, 2021 at 03:53:36PM -0500, Rob Herring escreveu: > > > > On Wed, Apr 14, 2021 at 3:25 PM Namhyung Kim <namhyung@kernel.org> wrote: > > > > > > +static inline void *xyarray__entry(struct xyarray *xy, int x, int y) > > > > > > +{ > > > > > > + if (x >= xy->max_x || y >= xy->max_y) > > > > > > + return NULL; > > > > > > > > > > Maybe better to check negatives as well. > > > > > > > > max_x and max_y are size_t and unsigned, so x and y will be promoted > > > > to unsigned and the check will still work. > > > > > > Fair enough, applied. > > > > So...: > > > > CC /tmp/build/perf/builtin-script.o > > In file included from xyarray.c:2: > > /home/acme/git/perf/tools/lib/perf/include/internal/xyarray.h: In function ‘xyarray__entry’: > > /home/acme/git/perf/tools/lib/perf/include/internal/xyarray.h:28:8: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare] > > 28 | if (x >= xy->max_x || y >= xy->max_y) > > | ^~ > > /home/acme/git/perf/tools/lib/perf/include/internal/xyarray.h:28:26: error: comparison of integer expressions of different signedness: ‘int’ and ‘size_t’ {aka ‘long unsigned int’} [-Werror=sign-compare] > > 28 | if (x >= xy->max_x || y >= xy->max_y) > > | ^~ > > cc1: all warnings being treated as errors > > > > > > Fedora 33's gcc complains, so I'll cast it to size_t.
I guess gcc 10.2 on ubuntu doesn't yet. I was somewhat expecting to see something and figured it was fine with -Wall...
Rob
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