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authorFrederic Weisbecker <fweisbec@gmail.com>2008-11-11 07:03:45 +0100
committerIngo Molnar <mingo@elte.hu>2008-11-11 10:29:11 +0100
commitcaf4b323b02a16c92fba449952ac6515ddc76d7a (patch)
tree6fc234d00faca192248344996a168afb253e5f40 /kernel
parentd844222a54c33a960755b44b934cd1b01b05dceb (diff)
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 'kernel')
-rw-r--r--kernel/Makefile4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 9a3ec66a9d8..af3be57acbb 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -23,6 +23,10 @@ CFLAGS_REMOVE_cgroup-debug.o = -pg
CFLAGS_REMOVE_sched_clock.o = -pg
CFLAGS_REMOVE_sched.o = -mno-spe -pg
endif
+ifdef CONFIG_FUNCTION_RET_TRACER
+CFLAGS_REMOVE_extable.o = -pg # For __kernel_text_address()
+CFLAGS_REMOVE_module.o = -pg # For __module_text_address()
+endif
obj-$(CONFIG_FREEZER) += freezer.o
obj-$(CONFIG_PROFILING) += profile.o