Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | (Eric W. Biederman) | Date | Wed, 09 Dec 2020 15:42:57 -0600 | Subject | [PATCH -1/24] exec: Don't open code get_close_on_exec |
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Al Viro pointed out that using the phrase "close_on_exec(fd, rcu_dereference_raw(current->files->fdt))" instead of wrapping it in rcu_read_lock(), rcu_read_unlock() is a very questionable optimization[1].
Once wrapped with rcu_read_lock()/rcu_read_unlock() that phrase becomes equivalent the helper function get_close_on_exec so simplify the code and make it more robust by simply using get_close_on_exec.
[1] https://lkml.kernel.org/r/20201207222214.GA4115853@ZenIV.linux.org.uk Suggested-by: Al Viro <viro@ftp.linux.org.uk> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> ---
I aim to rebase my exec branch and apply this tomorrow.
fs/exec.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c index 547a2390baf5..9aabf6e8c904 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1808,8 +1808,7 @@ static int bprm_execve(struct linux_binprm *bprm, * inaccessible after exec. Relies on having exclusive access to * current->files (due to unshare_files above). */ - if (bprm->fdpath && - close_on_exec(fd, rcu_dereference_raw(current->files->fdt))) + if (bprm->fdpath && get_close_on_exec(fd)) bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE; /* Set the unchanging part of bprm->cred */ -- 2.20.1
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