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perf tools: Fix endianity swapping for adds_features bitmask 

Based on Jiri's latest attempt:
https://lkml.org/lkml/2012/5/16/61

Basically, adds_features should be byte swapped assuming unsigned
longs are either 8-bytes (u64) or 4-bytes (u32).

    Fixes 32-bit ppc dumping 64-bit x86 feature data:
     ========
     captured on: Sun May 20 19:23:23 2012
     hostname : nxos-vdc-dev3
     os release : 3.4.0-rc7+
     perf version : 3.4.rc4.137.g978da3
     arch : x86_64
     nrcpus online : 16
     nrcpus avail : 16
     cpudesc : Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
     cpuid : GenuineIntel,6,26,5
     total memory : 24680324 kB
    ...

Verified 64-bit x86 can still dump feature data for 32-bit ppc.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/4FBBB539.5010805@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
David Ahern 2012-06-08 11:47:51 -03:00 committed by Arnaldo Carvalho de Melo
parent 9ee6ddc9da
commit 80c0120a3c
4 changed files with 22 additions and 7 deletions
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16
tools/perf/util/header.c
View File

@ -1942,7 +1942,6 @@ int perf_file_header__read(struct perf_file_header *header,
else
return -1;
} else if (ph->needs_swap) {
unsigned int i;
/*
* feature bitmap is declared as an array of unsigned longs --
* not good since its size can differ between the host that
@ -1958,14 +1957,17 @@ int perf_file_header__read(struct perf_file_header *header,
* file), punt and fallback to the original behavior --
* clearing all feature bits and setting buildid.
*/
for (i = 0; i < BITS_TO_LONGS(HEADER_FEAT_BITS); ++i)
header->adds_features[i] = bswap_64(header->adds_features[i]);
mem_bswap_64(&header->adds_features,
BITS_TO_U64(HEADER_FEAT_BITS));
if (!test_bit(HEADER_HOSTNAME, header->adds_features)) {
for (i = 0; i < BITS_TO_LONGS(HEADER_FEAT_BITS); ++i) {
header->adds_features[i] = bswap_64(header->adds_features[i]);
header->adds_features[i] = bswap_32(header->adds_features[i]);
}
/* unswap as u64 */
mem_bswap_64(&header->adds_features,
BITS_TO_U64(HEADER_FEAT_BITS));
/* unswap as u32 */
mem_bswap_32(&header->adds_features,
BITS_TO_U32(HEADER_FEAT_BITS));
}
if (!test_bit(HEADER_HOSTNAME, header->adds_features)) {

2
tools/perf/util/include/linux/bitops.h
View File

@ -8,6 +8,8 @@
#define BITS_PER_LONG __WORDSIZE
#define BITS_PER_BYTE 8
#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
#define BITS_TO_U64(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u64))
#define BITS_TO_U32(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))
#define for_each_set_bit(bit, addr, size) \
for ((bit) = find_first_bit((addr), (size)); \

10
tools/perf/util/session.c
View File

@ -442,6 +442,16 @@ static void perf_tool__fill_defaults(struct perf_tool *tool)
tool->finished_round = process_finished_round_stub;
}
}
void mem_bswap_32(void *src, int byte_size)
{
u32 *m = src;
while (byte_size > 0) {
*m = bswap_32(*m);
byte_size -= sizeof(u32);
++m;
}
}
void mem_bswap_64(void *src, int byte_size)
{

1
tools/perf/util/session.h
View File

@ -80,6 +80,7 @@ struct branch_info *machine__resolve_bstack(struct machine *self,
bool perf_session__has_traces(struct perf_session *self, const char *msg);
void mem_bswap_64(void *src, int byte_size);
void mem_bswap_32(void *src, int byte_size);
void perf_event__attr_swap(struct perf_event_attr *attr);
int perf_session__create_kernel_maps(struct perf_session *self);