[PATCH 5.15 023/917] parisc: Fix ptrace check on syscall return

Greg Kroah-Hartman
2021-11-16T01:12:24Z

From: Helge Deller <deller@gmx.de>

commit 8779e05ba8aaffec1829872ef9774a71f44f6580 upstream.

The TIF_XXX flags are stored in the flags field in the thread_info
struct (TI_FLAGS), not in the flags field of the task_struct structure
(TASK_FLAGS).

It seems this bug didn't generate any important side-effects, otherwise it
wouldn't have went unnoticed for 12 years (since v2.6.32).

Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: ecd3d4bc06e48 ("parisc: stop using task->ptrace for {single,block}step flags")
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/parisc/kernel/entry.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -1834,7 +1834,7 @@ syscall_restore:
LDREG TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1

/* Are we being ptraced? */
- ldw TASK_FLAGS(%r1),%r19
+ LDREG TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
ldi _TIF_SYSCALL_TRACE_MASK,%r2
and,COND(=) %r19,%r2,%r0
b,n syscall_restore_rfi