[PATCH 4/7 v2] Introduce linux_proc_pid_to_exec_file

Gary Benson
2015-04-15T13:14:45Z

This commit introduces a new function linux_proc_pid_to_exec_file
that shared Linux code can use to discover the filename of the
executable that was run to create a process on the system.

gdb/ChangeLog:

* nat/linux-procfs.h (linux_proc_pid_to_exec_file):
New declaration.
* nat/linux-procfs.c (linux_proc_pid_to_exec_file):
New function, factored out from...
* linux-nat.c (linux_child_pid_to_exec_file): ...here.
---
gdb/ChangeLog | 8 ++++++++
gdb/linux-nat.c | 10 +---------
gdb/nat/linux-procfs.c | 19 +++++++++++++++++++
gdb/nat/linux-procfs.h | 6 ++++++
4 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
index 6c198cf..b04aa68 100644
--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -4106,15 +4106,7 @@ linux_nat_thread_name (struct target_ops *self, struct thread_info *thr)
static char *
linux_child_pid_to_exec_file (struct target_ops *self, int pid)
{
- static char buf[PATH_MAX];
- char name[PATH_MAX];
-
- xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid);
- memset (buf, 0, PATH_MAX);
- if (readlink (name, buf, PATH_MAX - 1) <= 0)
- strcpy (buf, name);
-
- return buf;
+ return linux_proc_pid_to_exec_file (pid);
}

/* Implement the to_xfer_partial interface for memory reads using the /proc
diff --git a/gdb/nat/linux-procfs.c b/gdb/nat/linux-procfs.c
index 7599b32..44364c5 100644
--- a/gdb/nat/linux-procfs.c
+++ b/gdb/nat/linux-procfs.c
@@ -273,3 +273,22 @@ linux_proc_task_list_dir_exists (pid_t pid)
xsnprintf (pathname, sizeof (pathname), "/proc/%ld/task", (long) pid);
return (stat (pathname, &buf) == 0);
}
+
+/* See linux-procfs.h. */
+
+char *
+linux_proc_pid_to_exec_file (int pid)
+{
+ static char buf[PATH_MAX];
+ char name[PATH_MAX];
+ ssize_t len;
+
+ xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid);
+ len = readlink (name, buf, PATH_MAX - 1);
+ if (len <= 0)
+ strcpy (buf, name);
+ else
+ buf[len] = '\0';
+
+ return buf;
+}
diff --git a/gdb/nat/linux-procfs.h b/gdb/nat/linux-procfs.h
index c4f5788..fdbf383 100644
--- a/gdb/nat/linux-procfs.h
+++ b/gdb/nat/linux-procfs.h
@@ -73,4 +73,10 @@ extern void linux_proc_attach_tgid_threads (pid_t pid,
/* Return true if the /proc/PID/task/ directory exists. */
extern int linux_proc_task_list_dir_exists (pid_t pid);

+/* Return the full absolute name of the executable file that was run
+ to create the process PID. The returned value persists until this
+ function is next called. */
+
+extern char *linux_proc_pid_to_exec_file (int pid);
+
#endif /* COMMON_LINUX_PROCFS_H */
--
1.7.1