| Message ID | 1466660967-2016-1-git-send-email-maddy@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Thu, Jun 23, 2016 at 11:19:27AM +0530, Madhavan Srinivasan wrote: SNIP > > Changelog v1: > 1)updated commit message and patch subject > 2)Add the fix to print_sample_iregs() in builtin-script.c > > tools/include/linux/bitmap.h | 2 ++ > tools/lib/bitmap.c | 18 ++++++++++++++++++ > tools/perf/builtin-script.c | 4 +++- > tools/perf/util/session.c | 4 +++- > 4 files changed, 26 insertions(+), 2 deletions(-) > > diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h > index 28f5493da491..5e98525387dc 100644 > --- a/tools/include/linux/bitmap.h > +++ b/tools/include/linux/bitmap.h > @@ -2,6 +2,7 @@ > #define _PERF_BITOPS_H > > #include <string.h> > +#include <limits.h> this could go in the bitmap.c file, but anyway: Acked-by: Jiri Olsa <jolsa@kernel.org> thanks, jirka > #include <linux/bitops.h> > > #define DECLARE_BITMAP(name,bits) \ > @@ -10,6 +11,7 @@ > int __bitmap_weight(const unsigned long *bitmap, int bits); > void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, > const unsigned long *bitmap2, int bits); > +void bitmap_from_u64(unsigned long *dst, u64 mask); > > #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) > SNIP
Hi Arnaldo, Any updates for this fix. Kindly let me know. Maddy On Tuesday 28 June 2016 02:24 PM, Jiri Olsa wrote: > On Thu, Jun 23, 2016 at 11:19:27AM +0530, Madhavan Srinivasan wrote: > > SNIP > >> Changelog v1: >> 1)updated commit message and patch subject >> 2)Add the fix to print_sample_iregs() in builtin-script.c >> >> tools/include/linux/bitmap.h | 2 ++ >> tools/lib/bitmap.c | 18 ++++++++++++++++++ >> tools/perf/builtin-script.c | 4 +++- >> tools/perf/util/session.c | 4 +++- >> 4 files changed, 26 insertions(+), 2 deletions(-) >> >> diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h >> index 28f5493da491..5e98525387dc 100644 >> --- a/tools/include/linux/bitmap.h >> +++ b/tools/include/linux/bitmap.h >> @@ -2,6 +2,7 @@ >> #define _PERF_BITOPS_H >> >> #include <string.h> >> +#include <limits.h> > this could go in the bitmap.c file, but anyway: > > Acked-by: Jiri Olsa <jolsa@kernel.org> > > thanks, > jirka > >> #include <linux/bitops.h> >> >> #define DECLARE_BITMAP(name,bits) \ >> @@ -10,6 +11,7 @@ >> int __bitmap_weight(const unsigned long *bitmap, int bits); >> void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, >> const unsigned long *bitmap2, int bits); >> +void bitmap_from_u64(unsigned long *dst, u64 mask); >> >> #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) >> > SNIP >
diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h index 28f5493da491..5e98525387dc 100644 --- a/tools/include/linux/bitmap.h +++ b/tools/include/linux/bitmap.h @@ -2,6 +2,7 @@ #define _PERF_BITOPS_H #include <string.h> +#include <limits.h> #include <linux/bitops.h> #define DECLARE_BITMAP(name,bits) \ @@ -10,6 +11,7 @@ int __bitmap_weight(const unsigned long *bitmap, int bits); void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, int bits); +void bitmap_from_u64(unsigned long *dst, u64 mask); #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) diff --git a/tools/lib/bitmap.c b/tools/lib/bitmap.c index 0a1adc1111fd..464a0cc63e6a 100644 --- a/tools/lib/bitmap.c +++ b/tools/lib/bitmap.c @@ -29,3 +29,21 @@ void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, for (k = 0; k < nr; k++) dst[k] = bitmap1[k] | bitmap2[k]; } + +/* + * bitmap_from_u64 - Check and swap words within u64. + * @mask: source bitmap + * @dst: destination bitmap + * + * In 32 bit big endian userspace on a 64bit kernel, 'unsigned long' is 32 bits. + * When reading u64 using (u32 *)(&val)[0] and (u32 *)(&val)[1], + * we will get wrong value for the mask. That is "(u32 *)(&val)[0]" + * gets upper 32 bits of u64, but perf may expect lower 32bits of u64. + */ +void bitmap_from_u64(unsigned long *dst, u64 mask) +{ + dst[0] = mask & ULONG_MAX; + + if (sizeof(mask) > sizeof(unsigned long)) + dst[1] = mask >> 32; +} diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index e3ce2f34d3ad..132a4bb70c31 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -412,11 +412,13 @@ static void print_sample_iregs(struct perf_sample *sample, struct regs_dump *regs = &sample->intr_regs; uint64_t mask = attr->sample_regs_intr; unsigned i = 0, r; + DECLARE_BITMAP(_mask, 64); if (!regs) return; - for_each_set_bit(r, (unsigned long *) &mask, sizeof(mask) * 8) { + bitmap_from_u64(_mask, mask); + for_each_set_bit(r, _mask, sizeof(mask) * 8) { u64 val = regs->regs[i++]; printf("%5s:0x%"PRIx64" ", perf_reg_name(r), val); } diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 5214974e841a..35722226bf13 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -940,8 +940,10 @@ static void branch_stack__printf(struct perf_sample *sample) static void regs_dump__printf(u64 mask, u64 *regs) { unsigned rid, i = 0; + DECLARE_BITMAP(_mask, 64); - for_each_set_bit(rid, (unsigned long *) &mask, sizeof(mask) * 8) { + bitmap_from_u64(_mask, mask); + for_each_set_bit(rid, _mask, sizeof(mask) * 8) { u64 val = regs[i++]; printf(".... %-5s 0x%" PRIx64 "\n",
When decoding the perf_regs mask in regs_dump__printf(), we loop through the mask using find_first_bit and find_next_bit functions. "mask" is of type "u64", but sent as a "unsigned long *" to lib functions along with sizeof(). While the exisitng code works fine in most of the case, the logic is broken when using a 32bit perf on a 64bit kernel (Big Endian). When reading u64 using (u32 *)(&val)[0], perf (lib/find_*_bit()) assumes it gets lower 32bits of u64 which is wrong. Proposed fix is to swap the words of the u64 to handle this case. This is _not_ endianess swap. Suggested-by: Yury Norov <ynorov@caviumnetworks.com> Cc: Yury Norov <ynorov@caviumnetworks.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Wang Nan <wangnan0@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> --- Changelog v4: 1) Removed the new macro and resued the DECLARE_BITMAP Changelog v3: 1)Moved the swap function to lib/bitmap.c 2)Added a macro for declaration 3)Added the comments Changelog v2: 1)Moved the swap code to a common function 2)Added more comments in the code Changelog v1: 1)updated commit message and patch subject 2)Add the fix to print_sample_iregs() in builtin-script.c tools/include/linux/bitmap.h | 2 ++ tools/lib/bitmap.c | 18 ++++++++++++++++++ tools/perf/builtin-script.c | 4 +++- tools/perf/util/session.c | 4 +++- 4 files changed, 26 insertions(+), 2 deletions(-)