[PATCH 2/5] perf tools: Pass a fd to perf_file_header__read_pipe()

From: Namhyung Kim
Date: Mon Jul 19 2021 - 20:28:00 EST


Currently it unconditionally writes to stdout for repipe. But perf
inject can direct its output to a regular file. Then it needs to
write the header to the file as well.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/builtin-inject.c | 1 +
tools/perf/util/header.c | 12 ++++++------
tools/perf/util/header.h | 2 +-
tools/perf/util/session.c | 8 ++++----
tools/perf/util/session.h | 4 ++--
5 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 3cffb12f01be..d99f4538d2fc 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -992,6 +992,7 @@ int cmd_inject(int argc, const char **argv)

data.path = inject.input_name;
inject.session = __perf_session__new(&data, inject.output.is_pipe,
+ perf_data__fd(&inject.output),
&inject.tool);
if (IS_ERR(inject.session))
return PTR_ERR(inject.session);
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 44249027507a..f280b3a38646 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -3865,10 +3865,10 @@ static int perf_file_section__process(struct perf_file_section *section,
static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
struct perf_header *ph,
struct perf_data* data,
- bool repipe)
+ bool repipe, int repipe_fd)
{
struct feat_fd ff = {
- .fd = STDOUT_FILENO,
+ .fd = repipe_fd,
.ph = ph,
};
ssize_t ret;
@@ -3891,13 +3891,13 @@ static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
return 0;
}

-static int perf_header__read_pipe(struct perf_session *session)
+static int perf_header__read_pipe(struct perf_session *session, int repipe_fd)
{
struct perf_header *header = &session->header;
struct perf_pipe_file_header f_header;

if (perf_file_header__read_pipe(&f_header, header, session->data,
- session->repipe) < 0) {
+ session->repipe, repipe_fd) < 0) {
pr_debug("incompatible file format\n");
return -EINVAL;
}
@@ -3995,7 +3995,7 @@ static int evlist__prepare_tracepoint_events(struct evlist *evlist, struct tep_h
return 0;
}

-int perf_session__read_header(struct perf_session *session)
+int perf_session__read_header(struct perf_session *session, int repipe_fd)
{
struct perf_data *data = session->data;
struct perf_header *header = &session->header;
@@ -4016,7 +4016,7 @@ int perf_session__read_header(struct perf_session *session)
* We can read 'pipe' data event from regular file,
* check for the pipe header regardless of source.
*/
- err = perf_header__read_pipe(session);
+ err = perf_header__read_pipe(session, repipe_fd);
if (!err || perf_data__is_pipe(data)) {
data->is_pipe = true;
return err;
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index ae6b1cf19a7d..c9e3265832d9 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -115,7 +115,7 @@ struct perf_session;
struct perf_tool;
union perf_event;

-int perf_session__read_header(struct perf_session *session);
+int perf_session__read_header(struct perf_session *session, int repipe_fd);
int perf_session__write_header(struct perf_session *session,
struct evlist *evlist,
int fd, bool at_exit);
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index f76b18e3c061..a40dd37ac71e 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -102,11 +102,11 @@ static int perf_session__deliver_event(struct perf_session *session,
struct perf_tool *tool,
u64 file_offset);

-static int perf_session__open(struct perf_session *session)
+static int perf_session__open(struct perf_session *session, int repipe_fd)
{
struct perf_data *data = session->data;

- if (perf_session__read_header(session) < 0) {
+ if (perf_session__read_header(session, repipe_fd) < 0) {
pr_err("incompatible file format (rerun with -v to learn more)\n");
return -1;
}
@@ -186,7 +186,7 @@ static int ordered_events__deliver_event(struct ordered_events *oe,
}

struct perf_session *__perf_session__new(struct perf_data *data,
- bool repipe,
+ bool repipe, int repipe_fd,
struct perf_tool *tool)
{
int ret = -ENOMEM;
@@ -211,7 +211,7 @@ struct perf_session *__perf_session__new(struct perf_data *data,
session->data = data;

if (perf_data__is_read(data)) {
- ret = perf_session__open(session);
+ ret = perf_session__open(session, repipe_fd);
if (ret < 0)
goto out_delete;

diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 9d19d2a918c6..5d8bd14a0a39 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -55,13 +55,13 @@ struct decomp {
struct perf_tool;

struct perf_session *__perf_session__new(struct perf_data *data,
- bool repipe,
+ bool repipe, int repipe_fd,
struct perf_tool *tool);

static inline struct perf_session *perf_session__new(struct perf_data *data,
struct perf_tool *tool)
{
- return __perf_session__new(data, false, tool);
+ return __perf_session__new(data, false, -1, tool);
}

void perf_session__delete(struct perf_session *session);
--
2.32.0.402.g57bb445576-goog