Commit 9b7e30ab authored May 02, 2017 by Aurelien Jarno Committed by Rich Felker Apr 12, 2018

sh: fix futex FUTEX_OP_SET op on userspace addresses



Commit 00b73d8d ("sh: add working futex atomic ops on userspace
addresses for smp") changed the futex_atomic_op_inuser function to
use a loop. In case of the FUTEX_OP_SET op with a userspace address
containing a value different of 0, this loop is an endless loop.

Fix that by loading the value of oldval from the userspace before doing
the cmpxchg op, also for the FUTEX_OP_SET case.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Rich Felker <dalias@libc.org>

parent 0adb3285

arch/sh/include/asm/futex.h

+1 −4

Original line number	Diff line number	Diff line
		@@ -37,9 +37,6 @@ static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval,
		pagefault_disable();

		do {
		if (op == FUTEX_OP_SET)
		ret = oldval = 0;
		else
		ret = get_user(oldval, uaddr);

		if (ret) break;