From: "Steven Rostedt (VMware)" <rost...@goodmis.org> 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/20190524111144.gi2...@hirez.programming.kicks-ass.net Suggested-by: Peter Zijlstra <pet...@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhira...@kernel.org> Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org> --- 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
