call_usermodehelper(): increase reliability
Presently call_usermodehelper_setup() uses GFP_ATOMIC. but it can return
NULL _very_ easily.
GFP_ATOMIC is needed only when we can't sleep. and, GFP_KERNEL is robust
and better.
thus, I add gfp_mask argument to call_usermodehelper_setup().
So, its callers pass the gfp_t as below:
call_usermodehelper() and call_usermodehelper_keys():
depend on 'wait' argument.
call_usermodehelper_pipe():
always GFP_KERNEL because always run under process context.
orderly_poweroff():
pass to GFP_ATOMIC because may run under interrupt context.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: "Paul Menage" <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index 0509c4c..a1a9157 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -19,6 +19,7 @@
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
+#include <linux/gfp.h>
#include <linux/stddef.h>
#include <linux/errno.h>
#include <linux/compiler.h>
@@ -41,8 +42,8 @@
struct subprocess_info;
/* Allocate a subprocess_info structure */
-struct subprocess_info *call_usermodehelper_setup(char *path,
- char **argv, char **envp);
+struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
+ char **envp, gfp_t gfp_mask);
/* Set various pieces of state into the subprocess_info structure */
void call_usermodehelper_setkeys(struct subprocess_info *info,
@@ -69,8 +70,9 @@
call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait)
{
struct subprocess_info *info;
+ gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
- info = call_usermodehelper_setup(path, argv, envp);
+ info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
if (info == NULL)
return -ENOMEM;
return call_usermodehelper_exec(info, wait);
@@ -81,8 +83,9 @@
struct key *session_keyring, enum umh_wait wait)
{
struct subprocess_info *info;
+ gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
- info = call_usermodehelper_setup(path, argv, envp);
+ info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
if (info == NULL)
return -ENOMEM;