diff options
| author | KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> | 2010-10-27 15:34:08 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-27 18:03:12 -0700 |
| commit | 9b1bf12d5d51bca178dea21b04a0805e29d60cf1 (patch) | |
| tree | 902a2c0e5882a2152da59a589958d6426dc84643 /fs/exec.c | |
| parent | b84011508360d6885a9d95a235ec77d56f133377 (diff) | |
| download | lwn-9b1bf12d5d51bca178dea21b04a0805e29d60cf1.tar.gz lwn-9b1bf12d5d51bca178dea21b04a0805e29d60cf1.zip | |
signals: move cred_guard_mutex from task_struct to signal_struct
Oleg Nesterov pointed out we have to prevent multiple-threads-inside-exec
itself and we can reuse ->cred_guard_mutex for it. Yes, concurrent
execve() has no worth.
Let's move ->cred_guard_mutex from task_struct to signal_struct. It
naturally prevent multiple-threads-inside-exec.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/exec.c b/fs/exec.c index 3aa75b8888a1..9722909c4d88 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1083,14 +1083,14 @@ EXPORT_SYMBOL(setup_new_exec); */ int prepare_bprm_creds(struct linux_binprm *bprm) { - if (mutex_lock_interruptible(¤t->cred_guard_mutex)) + if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) return -ERESTARTNOINTR; bprm->cred = prepare_exec_creds(); if (likely(bprm->cred)) return 0; - mutex_unlock(¤t->cred_guard_mutex); + mutex_unlock(¤t->signal->cred_guard_mutex); return -ENOMEM; } @@ -1098,7 +1098,7 @@ void free_bprm(struct linux_binprm *bprm) { free_arg_pages(bprm); if (bprm->cred) { - mutex_unlock(¤t->cred_guard_mutex); + mutex_unlock(¤t->signal->cred_guard_mutex); abort_creds(bprm->cred); } kfree(bprm); @@ -1119,13 +1119,13 @@ void install_exec_creds(struct linux_binprm *bprm) * credentials; any time after this it may be unlocked. */ security_bprm_committed_creds(bprm); - mutex_unlock(¤t->cred_guard_mutex); + mutex_unlock(¤t->signal->cred_guard_mutex); } EXPORT_SYMBOL(install_exec_creds); /* * determine how safe it is to execute the proposed program - * - the caller must hold current->cred_guard_mutex to protect against + * - the caller must hold ->cred_guard_mutex to protect against * PTRACE_ATTACH */ int check_unsafe_exec(struct linux_binprm *bprm) |