coredump_filter: permit changing of the default filter

Introduce a new kernel parameter `coredump_filter'.  Setting a value to
this parameter causes the default bitmask of coredump_filter to be
changed.

It is useful for users to change coredump_filter settings for the whole
system at boot time.  Without this parameter, users have to change
coredump_filter settings for each /proc/<pid>/ in an initializing script.

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3ccf1bc5affe..0b3f6711d2f1 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -551,6 +551,11 @@ and is between 256 and 4096 characters. It is defined in the file
                         not work reliably with all consoles, but is known
                         to work with serial and VGA consoles.
 
+        coredump_filter=
+                        [KNL] Change the default value for
+                        /proc/<pid>/coredump_filter.
+                        See also Documentation/filesystems/proc.txt.
+
         cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
                         Format:
                         <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]