Commit ac331d15 authored by KOSAKI Motohiro's avatar KOSAKI Motohiro Committed by Linus Torvalds

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: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: "Paul Menage" <menage@google.com>
Reviewed-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Acked-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f557d099
......@@ -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;
......
......@@ -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;
......
......@@ -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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