fs/exec.c: fix initial stack reservation
Michael Neuling [Mon, 22 Feb 2010 20:44:24 +0000 (12:44 -0800)]
803bf5ec259941936262d10ecc84511b76a20921 ("fs/exec.c: restrict initial
stack space expansion to rlimit") attempts to limit the initial stack to
20*PAGE_SIZE.  Unfortunately, in attempting ensure the stack is not
reduced in size, we ended up not changing the stack at all.

This size reduction check is not necessary as the expand_stack call does
this already.

This caused a regression in UML resulting in most guest processes being
killed.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jouni Malinen <j@w1.fi>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/exec.c

index e95c692..cce6bbd 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -637,7 +637,6 @@ int setup_arg_pages(struct linux_binprm *bprm,
         * will align it up.
         */
        rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK;
-       rlim_stack = min(rlim_stack, stack_size);
 #ifdef CONFIG_STACK_GROWSUP
        if (stack_size + stack_expand > rlim_stack)
                stack_base = vma->vm_start + rlim_stack;