Commit 207e715f authored Apr 18, 2012 by Jonas Bonn

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 <david.hennerstrom@aacmicrotec.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>

parent 7b903e6c

arch/openrisc/kernel/entry.S

+4 −4

Original line number	Diff line number	Diff line
		@@ -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