Commit eda3913b authored by David Ahern's avatar David Ahern Committed by Ingo Molnar
Browse files

perf tools: Fix endian conversion reading event attr from file header 



The perf_event_attr struct has two __u32's at the top and
they need to be swapped individually.

With this change I was able to analyze a perf.data collected in a
32-bit PPC VM on an x86 system. I tested both 32-bit and 64-bit
binaries for the Intel analysis side; both read the PPC perf.data
file correctly.

-v2:
 - changed the existing perf_event__attr_swap() to swap only elements
   of perf_event_attr and exported it for use in swapping the
   attributes in the file header
 - updated swap_ops used for processing events

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: acme@ghostprotocols.net
Cc: peterz@infradead.org
Cc: paulus@samba.org
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/1310754849-12474-1-git-send-email-dsahern@gmail.com


Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 0111919d

tools/perf/util/header.c

+4 −1
Original line number Diff line number Diff line
@@ -877,9 +877,12 @@ int perf_session__read_header(struct perf_session *session, int fd) 
		struct perf_evsel *evsel;

		off_t tmp;



		if (perf_header__getbuffer64(header, fd, &f_attr, sizeof(f_attr)))

		if (readn(fd, &f_attr, sizeof(f_attr)) <= 0)

			goto out_errno;



		if (header->needs_swap)

			perf_event__attr_swap(&f_attr.attr);



		tmp = lseek(fd, 0, SEEK_CUR);

		evsel = perf_evsel__new(&f_attr.attr, i);

tools/perf/util/session.c

+18 −12
Original line number Diff line number Diff line
@@ -413,20 +413,26 @@ static void perf_event__read_swap(union perf_event *event) 
	event->read.id		 = bswap_64(event->read.id);

}



static void perf_event__attr_swap(union perf_event *event)

/* exported for swapping attributes in file header */

void perf_event__attr_swap(struct perf_event_attr *attr)

{

	attr->type		= bswap_32(attr->type);

	attr->size		= bswap_32(attr->size);

	attr->config		= bswap_64(attr->config);

	attr->sample_period	= bswap_64(attr->sample_period);

	attr->sample_type	= bswap_64(attr->sample_type);

	attr->read_format	= bswap_64(attr->read_format);

	attr->wakeup_events	= bswap_32(attr->wakeup_events);

	attr->bp_type		= bswap_32(attr->bp_type);

	attr->bp_addr		= bswap_64(attr->bp_addr);

	attr->bp_len		= bswap_64(attr->bp_len);

}



static void perf_event__hdr_attr_swap(union perf_event *event)

{

	size_t size;



	event->attr.attr.type		= bswap_32(event->attr.attr.type);

	event->attr.attr.size		= bswap_32(event->attr.attr.size);

	event->attr.attr.config		= bswap_64(event->attr.attr.config);

	event->attr.attr.sample_period	= bswap_64(event->attr.attr.sample_period);

	event->attr.attr.sample_type	= bswap_64(event->attr.attr.sample_type);

	event->attr.attr.read_format	= bswap_64(event->attr.attr.read_format);

	event->attr.attr.wakeup_events	= bswap_32(event->attr.attr.wakeup_events);

	event->attr.attr.bp_type	= bswap_32(event->attr.attr.bp_type);

	event->attr.attr.bp_addr	= bswap_64(event->attr.attr.bp_addr);

	event->attr.attr.bp_len		= bswap_64(event->attr.attr.bp_len);

	perf_event__attr_swap(&event->attr.attr);



	size = event->header.size;

	size -= (void *)&event->attr.id - (void *)event;
@@ -454,7 +460,7 @@ static perf_event__swap_op perf_event__swap_ops[] = { 
	[PERF_RECORD_LOST]		  = perf_event__all64_swap,

	[PERF_RECORD_READ]		  = perf_event__read_swap,

	[PERF_RECORD_SAMPLE]		  = perf_event__all64_swap,

	[PERF_RECORD_HEADER_ATTR]	  = perf_event__attr_swap,

	[PERF_RECORD_HEADER_ATTR]	  = perf_event__hdr_attr_swap,

	[PERF_RECORD_HEADER_EVENT_TYPE]	  = perf_event__event_type_swap,

	[PERF_RECORD_HEADER_TRACING_DATA] = perf_event__tracing_data_swap,

	[PERF_RECORD_HEADER_BUILD_ID]	  = NULL,

tools/perf/util/session.h

+1 −0
Original line number Diff line number Diff line
@@ -112,6 +112,7 @@ int perf_session__set_kallsyms_ref_reloc_sym(struct map **maps, 
					     u64 addr);



void mem_bswap_64(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);

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