Commit 0b3d3410 authored by David Carrillo-Cisneros's avatar David Carrillo-Cisneros Committed by Arnaldo Carvalho de Melo
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perf header: Add a buffer to struct feat_fd 



Extend struct feat_fd to use a temporal buffer in pipe-mode, instead of
perf.data's file descriptor.

The header features build_id and aux_trace already have logic to print
in file-mode that heavily rely on lseek the file. For now, leave such
features inactive in pipe-mode and print a warning if their functions
are called in pipe-mode.

Signed-off-by: default avatarDavid Carrillo-Cisneros <davidcc@google.com>
Acked-by: default avatarDavid Ahern <dsahern@gmail.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170718042549.145161-13-davidcc@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent a02c395c

tools/perf/util/header.c

+70 −5
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ struct perf_file_attr { 
struct feat_fd {

	struct perf_header	*ph;

	int			fd;

	void			*buf;	/* Either buf != NULL or fd >= 0 */

	ssize_t			offset;

	size_t			size;

};
@@ -81,18 +82,51 @@ bool perf_header__has_feat(const struct perf_header *header, int feat) 
	return test_bit(feat, header->adds_features);

}



/* Return: 0 if succeded, -ERR if failed. */

int do_write(struct feat_fd *ff, const void *buf, size_t size)

static int __do_write_fd(struct feat_fd *ff, const void *buf, size_t size)

{

	ssize_t ret;

	ssize_t ret = writen(ff->fd, buf, size);



	ret  = writen(ff->fd, buf, size);

	if (ret != (ssize_t)size)

		return ret < 0 ? (int)ret : -1;

	return 0;

}



static int __do_write_buf(struct feat_fd *ff,  const void *buf, size_t size)

{

	/* struct perf_event_header::size is u16 */

	const size_t max_size = 0xffff - sizeof(struct perf_event_header);

	size_t new_size = ff->size;

	void *addr;



	if (size + ff->offset > max_size)

		return -E2BIG;



	while (size > (new_size - ff->offset))

		new_size <<= 1;

	new_size = min(max_size, new_size);



	if (ff->size < new_size) {

		addr = realloc(ff->buf, new_size);

		if (!addr)

			return -ENOMEM;

		ff->buf = addr;

		ff->size = new_size;

	}



	memcpy(ff->buf + ff->offset, buf, size);

	ff->offset += size;



	return 0;

}



/* Return: 0 if succeded, -ERR if failed. */

int do_write(struct feat_fd *ff, const void *buf, size_t size)

{

	if (!ff->buf)

		return __do_write_fd(ff, buf, size);

	return __do_write_buf(ff, buf, size);

}



/* Return: 0 if succeded, -ERR if failed. */

int write_padded(struct feat_fd *ff, const void *bf,

		 size_t count, size_t count_aligned)
@@ -126,7 +160,7 @@ static int do_write_string(struct feat_fd *ff, const char *str) 
	return write_padded(ff, str, olen, len);

}



static int __do_read(struct feat_fd *ff, void *addr, ssize_t size)

static int __do_read_fd(struct feat_fd *ff, void *addr, ssize_t size)

{

	ssize_t ret = readn(ff->fd, addr, size);
@@ -135,6 +169,25 @@ static int __do_read(struct feat_fd *ff, void *addr, ssize_t size) 
	return 0;

}



static int __do_read_buf(struct feat_fd *ff, void *addr, ssize_t size)

{

	if (size > (ssize_t)ff->size - ff->offset)

		return -1;



	memcpy(addr, ff->buf + ff->offset, size);

	ff->offset += size;



	return 0;



}



static int __do_read(struct feat_fd *ff, void *addr, ssize_t size)

{

	if (!ff->buf)

		return __do_read_fd(ff, addr, size);

	return __do_read_buf(ff, addr, size);

}



static int do_read_u32(struct feat_fd *ff, u32 *addr)

{

	int ret;
@@ -189,6 +242,9 @@ static char *do_read_string(struct feat_fd *ff) 
static int write_tracing_data(struct feat_fd *ff,

			      struct perf_evlist *evlist)

{

	if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))

		return -1;



	return read_tracing_data(ff->fd, &evlist->entries);

}
@@ -203,6 +259,9 @@ static int write_build_id(struct feat_fd *ff, 
	if (!perf_session__read_build_ids(session, true))

		return -1;



	if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))

		return -1;



	err = perf_session__write_buildid_table(session, ff);

	if (err < 0) {

		pr_debug("failed to write buildid table\n");
@@ -912,6 +971,9 @@ static int write_auxtrace(struct feat_fd *ff, 
	struct perf_session *session;

	int err;



	if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))

		return -1;



	session = container_of(ff->ph, struct perf_session, header);



	err = auxtrace_index__write(ff->fd, &session->auxtrace_index);
@@ -2197,6 +2259,9 @@ static int do_write_feat(struct feat_fd *ff, int type, 
		if (!feat_ops[type].write)

			return -1;



		if (WARN(ff->buf, "Error: calling %s in pipe-mode.\n", __func__))

			return -1;



		(*p)->offset = lseek(ff->fd, 0, SEEK_CUR);



		err = feat_ops[type].write(ff, evlist);

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