When decoding the perf_regs mask in regs_dump__printf(), we loop through the mask using find_first_bit and find_next_bit functions. And mask is of type "u64". But "u64" is send as a "unsigned long *" to lib functions along with sizeof().
While the exisitng code works fine in most of the case, when using a 32bit perf on a 64bit kernel (Big Endian), we end up reading the wrong word in the u64 mask. Patch to fix the mask in regs_dump__printf(). Suggested-by: Yury Norov <yno...@caviumnetworks.com> Cc: Yury Norov <yno...@caviumnetworks.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Ingo Molnar <mi...@redhat.com> Cc: Arnaldo Carvalho de Melo <a...@kernel.org> Cc: Alexander Shishkin <alexander.shish...@linux.intel.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: Kan Liang <kan.li...@intel.com> Cc: Wang Nan <wangn...@huawei.com> Cc: Michael Ellerman <m...@ellerman.id.au> Signed-off-by: Madhavan Srinivasan <ma...@linux.vnet.ibm.com> --- tools/perf/util/session.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 5214974e841a..2eaa42a4832a 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -940,8 +940,13 @@ static void branch_stack__printf(struct perf_sample *sample) static void regs_dump__printf(u64 mask, u64 *regs) { unsigned rid, i = 0; + unsigned long _mask[sizeof(mask)/sizeof(unsigned long)]; - for_each_set_bit(rid, (unsigned long *) &mask, sizeof(mask) * 8) { + _mask[0] = mask & ULONG_MAX; + if (sizeof(mask) > sizeof(unsigned long)) + _mask[1] = mask >> 32; + + for_each_set_bit(rid, _mask, sizeof(mask) * 8) { u64 val = regs[i++]; printf(".... %-5s 0x%" PRIx64 "\n", -- 1.9.1 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev