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[PATCH] libdwfl: linux-pid-attach.c: Report actual PID (Tgid) to dwfl_attach_state.
- From: Mark Wielaard <mjw at redhat dot com>
- To: elfutils-devel at lists dot fedorahosted dot org
- Date: Mon, 23 Dec 2013 14:22:24 +0100
- Subject: [PATCH] libdwfl: linux-pid-attach.c: Report actual PID (Tgid) to dwfl_attach_state.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
---
libdwfl/ChangeLog | 5 +++++
libdwfl/linux-pid-attach.c | 21 +++++++++++++++++++++
src/ChangeLog | 4 ++++
src/stack.c | 2 ++
4 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog
index 723ea71..8a164f0 100644
--- a/libdwfl/ChangeLog
+++ b/libdwfl/ChangeLog
@@ -1,3 +1,8 @@
+2013-12-23 Mark Wielaard <mjw@redhat.com>
+
+ * linux-pid-attach.c (__libdwfl_attach_state_for_pid): Report actual
+ pid (thread group leader) to dwfl_attach_state.
+
2013-12-21 Mark Wielaard <mjw@redhat.com>
* linux-pid-attach.c (struct pid_arg): New field should_detach.
diff --git a/libdwfl/linux-pid-attach.c b/libdwfl/linux-pid-attach.c
index 1e1ccfa..232a3de 100644
--- a/libdwfl/linux-pid-attach.c
+++ b/libdwfl/linux-pid-attach.c
@@ -301,6 +301,27 @@ bool
internal_function
__libdwfl_attach_state_for_pid (Dwfl *dwfl, pid_t pid)
{
+ char buffer[36];
+ FILE *procfile;
+
+ /* Make sure to report the actual PID (thread group leader) to
+ dwfl_attach_state. */
+ snprintf (buffer, sizeof (buffer), "/proc/%ld/status", (long) pid);
+ procfile = fopen (buffer, "r");
+ if (procfile == NULL)
+ return false;
+
+ while (fgets (buffer, sizeof (buffer), procfile) != NULL)
+ if (strncmp (buffer, "Tgid:", 5) == 0)
+ {
+ pid = atoi (&buffer[5]);
+ break;
+ }
+ fclose (procfile);
+
+ if (pid == 0)
+ return false;
+
char dirname[64];
int i = snprintf (dirname, sizeof (dirname), "/proc/%ld/task", (long) pid);
assert (i > 0 && i < (ssize_t) sizeof (dirname) - 1);
diff --git a/src/ChangeLog b/src/ChangeLog
index ea30556..0f1b971 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,9 @@
2013-12-23 Mark Wielaard <mjw@redhat.com>
+ * stack.c (main): Print pid of process or core.
+
+2013-12-23 Mark Wielaard <mjw@redhat.com>
+
* stack.c (OPT_DEBUGINFO): New define.
(OPT_COREFILE): Likewise.
(pid): New static.
diff --git a/src/stack.c b/src/stack.c
index 3b0d767..dfb0272 100644
--- a/src/stack.c
+++ b/src/stack.c
@@ -376,6 +376,7 @@ main (int argc, char **argv)
if (show_one_tid)
{
+ printf ("TID %d:\n", pid);
switch (dwfl_getthread_frames (dwfl, pid, frame_callback, frames))
{
case DWARF_CB_OK:
@@ -391,6 +392,7 @@ main (int argc, char **argv)
}
else
{
+ printf ("PID %d - %s\n", dwfl_pid (dwfl), pid != 0 ? "process" : "core");
switch (dwfl_getthreads (dwfl, thread_callback, frames))
{
case DWARF_CB_OK:
--
1.7.1