[PATCH v2] powerpc/ftrace: restore caller's toc on ppc64 livepatch sibling call

[Ryan Sullivan]

Restores caller's toc pointer to r2, on a sibling call this will
uncorrupt the caller's toc pointer and otherwise will be redundant

Signed-off-by: Ryan Sullivan <rysulliv at redhat.com>
---
 arch/powerpc/kernel/trace/ftrace_entry.S | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/kernel/trace/ftrace_entry.S b/arch/powerpc/kernel/trace/ftrace_entry.S
index 76dbe9fd2c0f..4dfbe6076ad1 100644
--- a/arch/powerpc/kernel/trace/ftrace_entry.S
+++ b/arch/powerpc/kernel/trace/ftrace_entry.S
@@ -244,6 +244,9 @@ livepatch_handler:
 	mtlr	r12
 	ld	r2,  -24(r11)
 
+	/* Restore toc to caller's stack in case of sibling call */
+	std	r2, 24(r1)
+
 	/* Pop livepatch stack frame */
 	ld	r12, PACA_THREAD_INFO(r13)
 	subi	r11, r11, 24
-- 
2.44.0