From: "Steven Rostedt (VMware)" <[email protected]>
Instead of using "ALIGN()", use BUILD_BUG_ON() as the structures should
always be divisible by sizeof(long).
Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509093949.162236.14518699447151894536.stgit@devnote2
Link: http://lkml.kernel.org/r/[email protected]
Suggested-by: Peter Zijlstra <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
---
kernel/trace/fgraph.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index c62e6db718a0..fdb206aeffe3 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -33,7 +33,7 @@
* SHADOW_STACK_MAX_OFFSET: The max offset of the stack for a new frame to be added
*/
#define FGRAPH_FRAME_SIZE sizeof(struct ftrace_ret_stack)
-#define FGRAPH_FRAME_OFFSET (ALIGN(FGRAPH_FRAME_SIZE, sizeof(long)) / sizeof(long))
+#define FGRAPH_FRAME_OFFSET DIV_ROUND_UP(FGRAPH_FRAME_SIZE, sizeof(long))
#define SHADOW_STACK_SIZE (PAGE_SIZE)
#define SHADOW_STACK_OFFSET \
(ALIGN(SHADOW_STACK_SIZE, sizeof(long)) / sizeof(long))
@@ -103,6 +103,8 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func,
if (!current->ret_stack)
return -EBUSY;
+ BUILD_BUG_ON(SHADOW_STACK_SIZE % sizeof(long));
+
/*
* We must make sure the ret_stack is tested before we read
* anything else.
@@ -326,6 +328,8 @@ ftrace_graph_get_ret_stack(struct task_struct *task, int idx)
{
int index = task->curr_ret_stack;
+ BUILD_BUG_ON(FGRAPH_FRAME_SIZE % sizeof(long));
+
index -= FGRAPH_FRAME_OFFSET * (idx + 1);
if (index < 0)
return NULL;
--
2.43.0