coredump: add new %P variable in core_pattern
Add a new %P variable to be used in core_pattern. This variable contains
the global PID (PID in the init namespace) as %p contains the PID in the
current namespace which isn't always what we want.
The main use for this is to make it easier to handle crashes that happened
within a container. With that new variables it's possible to have the
crashes dumped into the container or forwarded to the host with the right
PID (from the host's point of view).
Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
Reported-by: Hans Feldt <hans.feldt@ericsson.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andy Whitcroft <apw@canonical.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 240ba92d4a528d7bc3fd08ad52081e108382809c)
Change-Id: I7b2530f271ed9c96b67cdb77777f8ad64f856a88
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 8d90c42..9b9d019 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -182,6 +182,7 @@
%<NUL> '%' is dropped
%% output one '%'
%p pid
+ %P global pid (init PID namespace)
%u uid
%g gid
%d dump mode, matches PR_SET_DUMPABLE and
diff --git a/fs/coredump.c b/fs/coredump.c
index 1d402ce..c962579 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -186,6 +186,11 @@
err = cn_printf(cn, "%d",
task_tgid_vnr(current));
break;
+ /* global pid */
+ case 'P':
+ err = cn_printf(cn, "%d",
+ task_tgid_nr(current));
+ break;
/* uid */
case 'u':
err = cn_printf(cn, "%d", cred->uid);
