Commit-ID: 781d06248234e221edb560a18461d65808a8a942 Gitweb: http://git.kernel.org/tip/781d06248234e221edb560a18461d65808a8a942 Author: Steven Rostedt <[email protected]> AuthorDate: Wed, 9 Feb 2011 13:27:22 -0500 Committer: Steven Rostedt <[email protected]> CommitDate: Thu, 23 Aug 2012 11:25:29 -0400
ftrace: Do not test frame pointers if -mfentry is used The function graph has a test to check if the frame pointer is corrupted, which can happen with various options of gcc with mcount. But this is not an issue with -mfentry as -mfentry does not need nor use frame pointers for function graph tracing. Link: http://lkml.kernel.org/r/[email protected] Acked-by: H. Peter Anvin <[email protected]> Acked-by: Ingo Molnar <[email protected]> Cc: Andi Kleen <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> --- kernel/trace/trace_functions_graph.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index ce27c8b..99b4378 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -143,7 +143,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, return; } -#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST +#if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY) /* * The arch may choose to record the frame pointer used * and check it here to make sure that it is what we expect it @@ -154,6 +154,9 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, * * Currently, x86_32 with optimize for size (-Os) makes the latest * gcc do the above. + * + * Note, -mfentry does not use frame pointers, and this test + * is not needed if CC_USING_FENTRY is set. */ if (unlikely(current->ret_stack[index].fp != frame_pointer)) { ftrace_graph_stop(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
