Also save r1 in ftrace_caller()
r1 is needed during unwinding when the function_graph tracer
is active.
Reported-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
Fixes: 830213786c49 ("powerpc/ftrace: directly call of function graph tracer by
ftrace caller")
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
arch/powerpc/kernel/trace/ftrace_mprofile.S | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/kernel/trace/ftrace_mprofile.S
b/arch/powerpc/kernel/trace/ftrace_mprofile.S
index 56da60e98327..8443902d5a05 100644
--- a/arch/powerpc/kernel/trace/ftrace_mprofile.S
+++ b/arch/powerpc/kernel/trace/ftrace_mprofile.S
@@ -173,6 +173,10 @@ _GLOBAL(ftrace_caller)
beq ftrace_no_trace
#endif
+ /* Save previous stack pointer (r1) */
+ addi r8, r1, SWITCH_FRAME_SIZE
+ PPC_STL r8, GPR1(r1)
+
/* Get the _mcount() call site out of LR */
mflr r7
PPC_STL r7, _NIP(r1)
--
2.34.1
