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Commit 938e4b22e2a7d0f6f3962e601339347b2d8e09f5

Authored by Lucas De Marchi
Committed by Linus Torvalds
1 parent 17afab1de4
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

usermodehelper: export call_usermodehelper_exec() and call_usermodehelper_setup() 

call_usermodehelper_setup() + call_usermodehelper_exec() need to be
called instead of call_usermodehelper_fns() when the cleanup function
needs to be called even when an ENOMEM error occurs.  In this case using
call_usermodehelper_fns() the user can't distinguish if the cleanup
function was called or not.

[akpm@linux-foundation.org: export call_usermodehelper_setup() to modules]
Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 2 changed files with 32 additions and 33 deletions Side-by-side Diff

include/linux/kmod.h
Diff comments   View file @ 938e4b2
... ... @@ -71,6 +71,14 @@
71 71 int (*init)(struct subprocess_info *info, struct cred *new),
72 72 void (*cleanup)(struct subprocess_info *), void *data);
73 73  
  74 +extern struct subprocess_info *
  75 +call_usermodehelper_setup(char *path, char **argv, char **envp, gfp_t gfp_mask,
  76 + int (*init)(struct subprocess_info *info, struct cred *new),
  77 + void (*cleanup)(struct subprocess_info *), void *data);
  78 +
  79 +extern int
  80 +call_usermodehelper_exec(struct subprocess_info *info, int wait);
  81 +
74 82 static inline int
75 83 call_usermodehelper(char *path, char **argv, char **envp, int wait)
76 84 {
... ... @@ -502,14 +502,28 @@
502 502 * @argv: arg vector for process
503 503 * @envp: environment for process
504 504 * @gfp_mask: gfp mask for memory allocation
  505 + * @cleanup: a cleanup function
  506 + * @init: an init function
  507 + * @data: arbitrary context sensitive data
505 508 *
506 509 * Returns either %NULL on allocation failure, or a subprocess_info
507 510 * structure. This should be passed to call_usermodehelper_exec to
508 511 * exec the process and free the structure.
  512 + *
  513 + * The init function is used to customize the helper process prior to
  514 + * exec. A non-zero return code causes the process to error out, exit,
  515 + * and return the failure to the calling process
  516 + *
  517 + * The cleanup function is just before ethe subprocess_info is about to
  518 + * be freed. This can be used for freeing the argv and envp. The
  519 + * Function must be runnable in either a process context or the
  520 + * context in which call_usermodehelper_exec is called.
509 521 */
510   -static
511 522 struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
512   - char **envp, gfp_t gfp_mask)
  523 + char **envp, gfp_t gfp_mask,
  524 + int (*init)(struct subprocess_info *info, struct cred *new),
  525 + void (*cleanup)(struct subprocess_info *info),
  526 + void *data)
513 527 {
514 528 struct subprocess_info *sub_info;
515 529 sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask);
516 530  
517 531  
... ... @@ -520,38 +534,16 @@
520 534 sub_info->path = path;
521 535 sub_info->argv = argv;
522 536 sub_info->envp = envp;
  537 +
  538 + sub_info->cleanup = cleanup;
  539 + sub_info->init = init;
  540 + sub_info->data = data;
523 541 out:
524 542 return sub_info;
525 543 }
  544 +EXPORT_SYMBOL(call_usermodehelper_setup);
526 545  
527 546 /**
528   - * call_usermodehelper_setfns - set a cleanup/init function
529   - * @info: a subprocess_info returned by call_usermodehelper_setup
530   - * @cleanup: a cleanup function
531   - * @init: an init function
532   - * @data: arbitrary context sensitive data
533   - *
534   - * The init function is used to customize the helper process prior to
535   - * exec. A non-zero return code causes the process to error out, exit,
536   - * and return the failure to the calling process
537   - *
538   - * The cleanup function is just before ethe subprocess_info is about to
539   - * be freed. This can be used for freeing the argv and envp. The
540   - * Function must be runnable in either a process context or the
541   - * context in which call_usermodehelper_exec is called.
542   - */
543   -static
544   -void call_usermodehelper_setfns(struct subprocess_info *info,
545   - int (*init)(struct subprocess_info *info, struct cred *new),
546   - void (*cleanup)(struct subprocess_info *info),
547   - void *data)
548   -{
549   - info->cleanup = cleanup;
550   - info->init = init;
551   - info->data = data;
552   -}
553   -
554   -/**
555 547 * call_usermodehelper_exec - start a usermode application
556 548 * @sub_info: information about the subprocessa
557 549 * @wait: wait for the application to finish and return status.
... ... @@ -563,7 +555,6 @@
563 555 * asynchronously if wait is not set, and runs as a child of keventd.
564 556 * (ie. it runs with full root capabilities).
565 557 */
566   -static
567 558 int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait)
568 559 {
569 560 DECLARE_COMPLETION_ONSTACK(done);
... ... @@ -615,6 +606,7 @@
615 606 helper_unlock();
616 607 return retval;
617 608 }
  609 +EXPORT_SYMBOL(call_usermodehelper_exec);
618 610  
619 611 /*
620 612 * call_usermodehelper_fns() will not run the caller-provided cleanup function
621 613  
... ... @@ -630,12 +622,11 @@
630 622 struct subprocess_info *info;
631 623 gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
632 624  
633   - info = call_usermodehelper_setup(path, argv, envp, gfp_mask);
  625 + info = call_usermodehelper_setup(path, argv, envp, gfp_mask,
  626 + init, cleanup, data);
634 627  
635 628 if (info == NULL)
636 629 return -ENOMEM;
637   -
638   - call_usermodehelper_setfns(info, init, cleanup, data);
639 630  
640 631 return call_usermodehelper_exec(info, wait);
641 632 }