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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2008-11-11 07:03:45 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-11 10:29:11 +0100 |
| commit | caf4b323b02a16c92fba449952ac6515ddc76d7a (patch) | |
| tree | 6fc234d00faca192248344996a168afb253e5f40 /include/linux/ftrace_irq.h | |
| parent | d844222a54c33a960755b44b934cd1b01b05dceb (diff) | |
| download | blackbird-op-linux-caf4b323b02a16c92fba449952ac6515ddc76d7a.tar.gz blackbird-op-linux-caf4b323b02a16c92fba449952ac6515ddc76d7a.zip | |
tracing, x86: add low level support for ftrace return tracing
Impact: add infrastructure for function-return tracing
Add low level support for ftrace return tracing.
This plug-in stores return addresses on the thread_info structure of
the current task.
The index of the current return address is initialized when the task
is the first one (init) and when a process forks (the child). It is
not needed when a task does a sys_execve because after this syscall,
it still needs to return on the kernel functions it called.
Note that the code of return_to_handler has been suggested by Steven
Rostedt as almost all of the ideas of improvements in this V3.
For purpose of security, arch/x86/kernel/process_32.c is not traced
because __switch_to() changes the current task during its execution.
That could cause inconsistency in the stored return address of this
function even if I didn't have any crash after testing with tracing on
this function enabled.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/ftrace_irq.h')
| -rw-r--r-- | include/linux/ftrace_irq.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/ftrace_irq.h b/include/linux/ftrace_irq.h index b1299d6729f2..0b4df55d7a74 100644 --- a/include/linux/ftrace_irq.h +++ b/include/linux/ftrace_irq.h @@ -2,7 +2,7 @@ #define _LINUX_FTRACE_IRQ_H -#ifdef CONFIG_DYNAMIC_FTRACE +#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_FUNCTION_RET_TRACER) extern void ftrace_nmi_enter(void); extern void ftrace_nmi_exit(void); #else |
