Commit 26b95137 authored Jun 14, 2018 by Alexey Dobriyan Committed by Linus Torvalds Jun 15, 2018

proc: skip branch in /proc// lookup

Code is structured like this:

	for ( ... p < last; p++) {
		if (memcmp == 0)
			break;
	}
	if (p >= last)
		ERROR
	OK

gcc doesn't see that if if lookup succeeds than post loop branch will
never be taken and skip it.

[akpm@linux-foundation.org: proc_pident_instantiate() no longer takes an inode*]
Link: http://lkml.kernel.org/r/20180423213954.GD9043@avx2


Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 37a4094e

fs/proc/base.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -2439,14 +2439,11 @@ static struct dentry proc_pident_lookup(struct inode dir,
		for (p = ents; p < last; p++) {
		if (p->len != dentry->d_name.len)
		continue;
		if (!memcmp(dentry->d_name.name, p->name, p->len))
		if (!memcmp(dentry->d_name.name, p->name, p->len)) {
		res = proc_pident_instantiate(dentry, task, p);
		break;
		}
		if (p >= last)
		goto out;

		res = proc_pident_instantiate(dentry, task, p);
		out:
		}
		put_task_struct(task);
		out_no_task:
		return res;