[PATCH 5.10 64/86] ARC: entry: fix syscall_trace_exit argument

From: Greg Kroah-Hartman
Date: Tue Apr 26 2022 - 05:05:01 EST

From: Sergey Matyukevich <sergey.matyukevich@xxxxxxxxxxxx>

commit b1c6ecfdd06907554518ec384ce8e99889d15193 upstream.

Function syscall_trace_exit expects pointer to pt_regs. However
r0 is also used to keep syscall return value. Restore pointer
to pt_regs before calling syscall_trace_exit.

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Sergey Matyukevich <sergey.matyukevich@xxxxxxxxxxxx>
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
arch/arc/kernel/entry.S | 1 +
1 file changed, 1 insertion(+)

--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -199,6 +199,7 @@ tracesys_exit:
st r0, [sp, PT_r0] ; sys call return value in pt_regs

;POST Sys Call Ptrace Hook
+ mov r0, sp ; pt_regs needed
bl @syscall_trace_exit
b ret_from_exception ; NOT ret_from_system_call at is saves r0 which
; we'd done before calling post hook above