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authorKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>2008-07-25 01:45:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 10:53:28 -0700
commitac331d158e198d2a91a5b0a3ec4ca9991fdb57af (patch)
treeb0921e2bc8e59d5df2c554c41c3b9f04e05d6d7c
parentf557d0996a6f9c06912528ea85e1dba0fb7d485f (diff)
downloadop-kernel-dev-ac331d158e198d2a91a5b0a3ec4ca9991fdb57af.zip
op-kernel-dev-ac331d158e198d2a91a5b0a3ec4ca9991fdb57af.tar.gz
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>
-rw-r--r--include/linux/kmod.h11
-rw-r--r--kernel/kmod.c9
-rw-r--r--kernel/sys.c2
3 files changed, 13 insertions, 9 deletions
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 file;
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 @@ static inline int
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 @@ call_usermodehelper_keys(char *path, char **argv, char **envp,
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;
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 2989f67..2456d1a 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -352,16 +352,17 @@ static inline void register_pm_notifier_callback(void) {}
* @path: path to usermode executable
* @argv: arg vector for process
* @envp: environment for process
+ * @gfp_mask: gfp mask for memory allocation
*
* Returns either %NULL on allocation failure, or a subprocess_info
* structure. This should be passed to call_usermodehelper_exec to
* exec the process and free the 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)
{
struct subprocess_info *sub_info;
- sub_info = kzalloc(sizeof(struct subprocess_info), GFP_ATOMIC);
+ sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask);
if (!sub_info)
goto out;
@@ -494,7 +495,7 @@ int call_usermodehelper_pipe(char *path, char **argv, char **envp,
struct subprocess_info *sub_info;
int ret;
- sub_info = call_usermodehelper_setup(path, argv, envp);
+ sub_info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL);
if (sub_info == NULL)
return -ENOMEM;
diff --git a/kernel/sys.c b/kernel/sys.c
index 14e9728..6c21880 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1795,7 +1795,7 @@ int orderly_poweroff(bool force)
goto out;
}
- info = call_usermodehelper_setup(argv[0], argv, envp);
+ info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC);
if (info == NULL) {
argv_free(argv);
goto out;
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