[PATCH 5.15 112/244] nios2: fix syscall restart checks

Greg Kroah-Hartman
2022-08-23T10:06:53Z

From: Al Viro <viro@zeniv.linux.org.uk>

commit 2d631bd58fe0ea3e3350212e23c9aba1fb606514 upstream.

sys_foo() returns -512 (aka -ERESTARTSYS) => do_signal() sees
512 in r2 and 1 in r1.

sys_foo() returns 512 => do_signal() sees 512 in r2 and 0 in r1.

The former is restart-worthy; the latter obviously isn't.

Fixes: b53e906d255d ("nios2: Signal handling support")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/nios2/kernel/signal.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/nios2/kernel/signal.c
+++ b/arch/nios2/kernel/signal.c
@@ -242,7 +242,7 @@ static int do_signal(struct pt_regs *reg
/*
* If we were from a system call, check for system call restarting...
*/
- if (regs->orig_r2 >= 0) {
+ if (regs->orig_r2 >= 0 && regs->r1) {
continue_addr = regs->ea;
restart_addr = continue_addr - 4;
retval = regs->r2;