Messages in this thread Patch in this message | | | Date | Thu, 13 Sep 2012 23:00:17 -0400 | From | Steven Rostedt <> | Subject | [PATCH 5/6 v2] ftrace/x86-64: Allow to change RIP in handlers |
| |
From: Steven Rostedt <rostedt@goodmis.org>
Allow ftrace handlers to change RIP register (regs->ip) in handlers. This will allow handlers to call another function instead of original function.
Link: http://lkml.kernel.org/r/20120905143118.10329.5078.stgit@localhost.localdomain
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- arch/x86/kernel/entry_64.S | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index ed767b7..e9cc2b3 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -165,6 +165,10 @@ GLOBAL(ftrace_regs_call) movq EFLAGS(%rsp), %rax movq %rax, SS(%rsp) + /* Handlers can change the RIP */ + movq RIP(%rsp), %rax + movq %rax, SS+8(%rsp) + /* restore the rest of pt_regs */ movq R15(%rsp), %r15 movq R14(%rsp), %r14 -- 1.7.10.4
[unhandled content-type:application/pgp-signature] | |