diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2016-08-19 06:52:57 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-08-24 12:15:14 +0200 |
| commit | 9a7c348ba6a46f6270d4fe49577649dad5664fe7 (patch) | |
| tree | 747a399fc9f6f3f1e234e27a164b9bb5e6ac015a /include/linux/ftrace.h | |
| parent | daa460a88c09b26b68e8b017de589c217e901afb (diff) | |
| download | lwn-9a7c348ba6a46f6270d4fe49577649dad5664fe7.tar.gz lwn-9a7c348ba6a46f6270d4fe49577649dad5664fe7.zip | |
ftrace: Add return address pointer to ftrace_ret_stack
Storing this value will help prevent unwinders from getting out of sync
with the function graph tracer ret_stack. Now instead of needing a
stateful iterator, they can compare the return address pointer to find
the right ret_stack entry.
Note that an array of 50 ftrace_ret_stack structs is allocated for every
task. So when an arch implements this, it will add either 200 or 400
bytes of memory usage per task (depending on whether it's a 32-bit or
64-bit platform).
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/ftrace.h')
| -rw-r--r-- | include/linux/ftrace.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 4ad9ccc60e38..483e02a50d37 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -798,6 +798,9 @@ struct ftrace_ret_stack { #ifdef HAVE_FUNCTION_GRAPH_FP_TEST unsigned long fp; #endif +#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR + unsigned long *retp; +#endif }; /* @@ -809,7 +812,7 @@ extern void return_to_handler(void); extern int ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, - unsigned long frame_pointer); + unsigned long frame_pointer, unsigned long *retp); /* * Sometimes we don't want to trace a function with the function |