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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 /arch/x86/kernel/Makefile | |
| parent | d844222a54c33a960755b44b934cd1b01b05dceb (diff) | |
| download | linux-caf4b323b02a16c92fba449952ac6515ddc76d7a.tar.gz linux-caf4b323b02a16c92fba449952ac6515ddc76d7a.tar.bz2 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 'arch/x86/kernel/Makefile')
| -rw-r--r-- | arch/x86/kernel/Makefile | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index e489ff9cb3e2..1d8ed95da846 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -14,6 +14,11 @@ CFLAGS_REMOVE_paravirt-spinlocks.o = -pg CFLAGS_REMOVE_ftrace.o = -pg endif +ifdef CONFIG_FUNCTION_RET_TRACER +# Don't trace __switch_to() but let it for function tracer +CFLAGS_REMOVE_process_32.o = -pg +endif + # # vsyscalls (which work on the user stack) should have # no stack-protector checks: @@ -65,6 +70,7 @@ obj-$(CONFIG_X86_LOCAL_APIC) += apic.o nmi.o obj-$(CONFIG_X86_IO_APIC) += io_apic.o obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups_32.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o +obj-$(CONFIG_FUNCTION_RET_TRACER) += ftrace.o obj-$(CONFIG_KEXEC) += machine_kexec_$(BITS).o obj-$(CONFIG_KEXEC) += relocate_kernel_$(BITS).o crash.o obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o |