[tip:perf/core] perf trace: Split fd -> pathname array handling

From: tip-bot for Arnaldo Carvalho de Melo
Date: Wed Oct 23 2013 - 03:53:23 EST


Commit-ID: 97119f37bbebbab852899bd37ed52b80396728f9
Gitweb: http://git.kernel.org/tip/97119f37bbebbab852899bd37ed52b80396728f9
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Fri, 27 Sep 2013 17:34:10 -0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 16 Oct 2013 11:05:01 -0300

perf trace: Split fd -> pathname array handling

So that the part that grows the array as needed is untied from the code
that reads the /proc/pid/fd symlink and can be used for the vfs_getname
hook that will set the fd -> path translation too, when available.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-ydo5rumyv9hdc1vsfmqamugs@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-trace.c | 49 +++++++++++++++++++++++++---------------------
1 file changed, 27 insertions(+), 22 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index d0f91fe..763bef4 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -975,30 +975,9 @@ struct trace {
double runtime_ms;
};

-static int thread__read_fd_path(struct thread *thread, int fd)
+static int trace__set_fd_pathname(struct thread *thread, int fd, const char *pathname)
{
struct thread_trace *ttrace = thread->priv;
- char linkname[PATH_MAX], pathname[PATH_MAX];
- struct stat st;
- int ret;
-
- if (thread->pid_ == thread->tid) {
- scnprintf(linkname, sizeof(linkname),
- "/proc/%d/fd/%d", thread->pid_, fd);
- } else {
- scnprintf(linkname, sizeof(linkname),
- "/proc/%d/task/%d/fd/%d", thread->pid_, thread->tid, fd);
- }
-
- if (lstat(linkname, &st) < 0 || st.st_size + 1 > (off_t)sizeof(pathname))
- return -1;
-
- ret = readlink(linkname, pathname, sizeof(pathname));
-
- if (ret < 0 || ret > st.st_size)
- return -1;
-
- pathname[ret] = '\0';

if (fd > ttrace->paths.max) {
char **npath = realloc(ttrace->paths.table, (fd + 1) * sizeof(char *));
@@ -1022,6 +1001,32 @@ static int thread__read_fd_path(struct thread *thread, int fd)
return ttrace->paths.table[fd] != NULL ? 0 : -1;
}

+static int thread__read_fd_path(struct thread *thread, int fd)
+{
+ char linkname[PATH_MAX], pathname[PATH_MAX];
+ struct stat st;
+ int ret;
+
+ if (thread->pid_ == thread->tid) {
+ scnprintf(linkname, sizeof(linkname),
+ "/proc/%d/fd/%d", thread->pid_, fd);
+ } else {
+ scnprintf(linkname, sizeof(linkname),
+ "/proc/%d/task/%d/fd/%d", thread->pid_, thread->tid, fd);
+ }
+
+ if (lstat(linkname, &st) < 0 || st.st_size + 1 > (off_t)sizeof(pathname))
+ return -1;
+
+ ret = readlink(linkname, pathname, sizeof(pathname));
+
+ if (ret < 0 || ret > st.st_size)
+ return -1;
+
+ pathname[ret] = '\0';
+ return trace__set_fd_pathname(thread, fd, pathname);
+}
+
static const char *thread__fd_path(struct thread *thread, int fd, bool live)
{
struct thread_trace *ttrace = thread->priv;
--
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