Commit 4605f057 authored Aug 11, 2020 by Wenchao Hao Committed by Linus Torvalds Aug 12, 2020

mm/mempolicy.c: check parameters first in kernel_get_mempolicy



Previous implementatoin calls untagged_addr() before error check, while if
the error check failed and return EINVAL, the untagged_addr() call is just
useless work.

Signed-off-by: Wenchao Hao <haowenchao22@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200801090825.5597-1-haowenchao22@gmail.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent f6e92f40

mm/mempolicy.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1632,11 +1632,11 @@ static int kernel_get_mempolicy(int __user *policy,
		int pval;
		nodemask_t nodes;

		addr = untagged_addr(addr);

		if (nmask != NULL && maxnode < nr_node_ids)
		return -EINVAL;

		addr = untagged_addr(addr);

		err = do_get_mempolicy(&pval, &nodes, addr, flags);

		if (err)