diff options
| author | Paul Mackerras <paulus@samba.org> | 2009-03-21 15:31:47 +1100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-06 09:30:18 +0200 |
| commit | 9aaa131a279834dff75c290c91f0058f62d72d46 (patch) | |
| tree | d996052d5cdc48b38e300d2b3d87f64cf97ede15 /include/linux | |
| parent | db4fb5acf20295063d1d5105e67724eb51440207 (diff) | |
perf_counter: fix type/event_id layout on big-endian systems
Impact: build fix for powerpc
Commit db3a944aca35ae61 ("perf_counter: revamp syscall input ABI")
expanded the hw_event.type field into a union of structs containing
bitfields. In particular it introduced a type field and a raw_type
field, with the intention that the 1-bit raw_type field should
overlay the most-significant bit of the 8-bit type field, and in fact
perf_counter_alloc() now assumes that (or at least, assumes that
raw_type doesn't overlay any of the bits that are 1 in the values of
PERF_TYPE_{HARDWARE,SOFTWARE,TRACEPOINT}).
Unfortunately this is not true on big-endian systems such as PowerPC,
where bitfields are laid out from left to right, i.e. from most
significant bit to least significant. This means that setting
hw_event.type = PERF_TYPE_SOFTWARE will set hw_event.raw_type to 1.
This fixes it by making the layout depend on whether or not
__BIG_ENDIAN_BITFIELD is defined. It's a bit ugly, but that's what
we get for using bitfields in a user/kernel ABI.
Also, that commit didn't fix up some places in arch/powerpc/kernel/
perf_counter.c where hw_event.raw and hw_event.event_id were used.
This fixes them too.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/perf_counter.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index a4b76c0175f..98f5990be1e 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -15,6 +15,7 @@ #include <linux/types.h> #include <linux/ioctl.h> +#include <asm/byteorder.h> /* * User-space ABI bits: @@ -86,6 +87,7 @@ enum perf_counter_record_type { */ struct perf_counter_hw_event { union { +#ifndef __BIG_ENDIAN_BITFIELD struct { __u64 event_id : 56, type : 8; @@ -94,6 +96,16 @@ struct perf_counter_hw_event { __u64 raw_event_id : 63, raw_type : 1; }; +#else + struct { + __u64 type : 8, + event_id : 56; + }; + struct { + __u64 raw_type : 1, + raw_event_id : 63; + }; +#endif /* __BIT_ENDIAN_BITFIELD */ __u64 event_config; }; |