From: Jonas Bonn Date: Wed, 18 Apr 2012 10:23:39 +0000 (+0200) Subject: openrisc: use scratch regs in atomic syscall X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=207e715ff17b42e022df107210dc8c736a703eb3;p=deliverable%2Flinux.git openrisc: use scratch regs in atomic syscall The function sys_or1k_atomic was using call-saved registers without restoring their value before returning. This is a faux pas: either we need to restore their values or use scratch regs; the latter is less code so that's the route this patch takes. Thanks to David Hennerström for doing most of the heavy-lifting in tracking this one down. Reported-by: Davd Hennerström Signed-off-by: Jonas Bonn --- diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S index 6e61af8682b8..ddfcaa828b0e 100644 --- a/arch/openrisc/kernel/entry.S +++ b/arch/openrisc/kernel/entry.S @@ -1117,10 +1117,10 @@ ENTRY(sys_rt_sigreturn) ENTRY(sys_or1k_atomic) /* FIXME: This ignores r3 and always does an XCHG */ DISABLE_INTERRUPTS(r17,r19) - l.lwz r30,0(r4) - l.lwz r28,0(r5) - l.sw 0(r4),r28 - l.sw 0(r5),r30 + l.lwz r29,0(r4) + l.lwz r27,0(r5) + l.sw 0(r4),r27 + l.sw 0(r5),r29 ENABLE_INTERRUPTS(r17) l.jr r9 l.or r11,r0,r0