[PATCH 1/3] ftrace: Look up the address of return_to_handler() using helpers

From: Naveen N. Rao
Date: Thu Sep 05 2019 - 14:21:00 EST


This ensures that we use the right address on architectures that use
function descriptors.

Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
---
kernel/trace/fgraph.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 8dfd5021b933..7950a0356042 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -276,7 +276,7 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
int index = task->curr_ret_stack;
int i;

- if (ret != (unsigned long)return_to_handler)
+ if (ret != (unsigned long)dereference_kernel_function_descriptor(return_to_handler))
return ret;

if (index < 0)
@@ -294,7 +294,7 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
{
int task_idx;

- if (ret != (unsigned long)return_to_handler)
+ if (ret != (unsigned long)dereference_kernel_function_descriptor(return_to_handler))
return ret;

task_idx = task->curr_ret_stack;
--
2.23.0