diff options
| -rw-r--r-- | tools/perf/util/session.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 4dcc8f3190c..17c9ace445c 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -481,6 +481,38 @@ static void perf_event__read_swap(union perf_event *event) event->read.id = bswap_64(event->read.id); } +static u8 revbyte(u8 b) +{ + int rev = (b >> 4) | ((b & 0xf) << 4); + rev = ((rev & 0xcc) >> 2) | ((rev & 0x33) << 2); + rev = ((rev & 0xaa) >> 1) | ((rev & 0x55) << 1); + return (u8) rev; +} + +/* + * XXX this is hack in attempt to carry flags bitfield + * throught endian village. ABI says: + * + * Bit-fields are allocated from right to left (least to most significant) + * on little-endian implementations and from left to right (most to least + * significant) on big-endian implementations. + * + * The above seems to be byte specific, so we need to reverse each + * byte of the bitfield. 'Internet' also says this might be implementation + * specific and we probably need proper fix and carry perf_event_attr + * bitfield flags in separate data file FEAT_ section. Thought this seems + * to work for now. + */ +static void swap_bitfield(u8 *p, unsigned len) +{ + unsigned i; + + for (i = 0; i < len; i++) { + *p = revbyte(*p); + p++; + } +} + /* exported for swapping attributes in file header */ void perf_event__attr_swap(struct perf_event_attr *attr) { @@ -494,6 +526,8 @@ void perf_event__attr_swap(struct perf_event_attr *attr) attr->bp_type = bswap_32(attr->bp_type); attr->bp_addr = bswap_64(attr->bp_addr); attr->bp_len = bswap_64(attr->bp_len); + + swap_bitfield((u8 *) (&attr->read_format + 1), sizeof(u64)); } static void perf_event__hdr_attr_swap(union perf_event *event) |