Messages in this thread Patch in this message | | | Date | Fri, 14 Sep 2012 04:44:23 -0700 | From | tip-bot for Steven Rostedt <> | Subject | [tip:perf/core] ftrace/x86-64: Allow to change RIP in handlers |
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Commit-ID: 47d5a5f88b9d25d6464c9b60c28f391e84e3ed65 Gitweb: http://git.kernel.org/tip/47d5a5f88b9d25d6464c9b60c28f391e84e3ed65 Author: Steven Rostedt <rostedt@goodmis.org> AuthorDate: Wed, 5 Sep 2012 23:31:18 +0900 Committer: Steven Rostedt <rostedt@goodmis.org> CommitDate: Thu, 13 Sep 2012 22:52:10 -0400
ftrace/x86-64: Allow to change RIP in handlers
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 files changed, 4 insertions(+), 0 deletions(-)
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
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