Merge tag 'powerpc-6.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - Fix arch_stack_walk_reliable(), used by live patching

 - Fix powerpc selftests to work with run_kselftest.sh

Thanks to Joe Lawrence and Petr Mladek.

* tag 'powerpc-6.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  selftests/powerpc: Fix emit_tests to work with run_kselftest.sh
  powerpc/stacktrace: Fix arch_stack_walk_reliable()

1 files changed, 5 insertions, 22 deletions

diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index b15f15dcacb5..e6a958a5da27 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -73,29 +73,12 @@ int __no_sanitize_address arch_stack_walk_reliable(stack_trace_consume_fn consum
 	bool firstframe;
 
 	stack_end = stack_page + THREAD_SIZE;
-	if (!is_idle_task(task)) {
-		/*
-		 * For user tasks, this is the SP value loaded on
-		 * kernel entry, see "PACAKSAVE(r13)" in _switch() and
-		 * system_call_common().
-		 *
-		 * Likewise for non-swapper kernel threads,
-		 * this also happens to be the top of the stack
-		 * as setup by copy_thread().
-		 *
-		 * Note that stack backlinks are not properly setup by
-		 * copy_thread() and thus, a forked task() will have
-		 * an unreliable stack trace until it's been
-		 * _switch()'ed to for the first time.
-		 */
-		stack_end -= STACK_USER_INT_FRAME_SIZE;
-	} else {
-		/*
-		 * idle tasks have a custom stack layout,
-		 * c.f. cpu_idle_thread_init().
-		 */
+
+	// See copy_thread() for details.
+	if (task->flags & PF_KTHREAD)
 		stack_end -= STACK_FRAME_MIN_SIZE;
-	}
+	else
+		stack_end -= STACK_USER_INT_FRAME_SIZE;
 
 	if (task == current)
 		sp = current_stack_frame();