Messages in this thread | | | Date | Mon, 4 Jun 2018 16:16:12 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v4 21/27] x86/ftrace: Adapt function tracing for PIE support |
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On Tue, 29 May 2018 15:15:22 -0700 Thomas Garnier <thgarnie@google.com> wrote:
> When using -fPIE/PIC with function tracing, the compiler generates a > call through the GOT (call *__fentry__@GOTPCREL). This instruction > takes 6 bytes instead of 5 on the usual relative call. > > If PIE is enabled, replace the 6th byte of the GOT call by a 1-byte nop > so ftrace can handle the previous 5-bytes as before. > > Position Independent Executable (PIE) support will allow to extend the > KASLR randomization range 0xffffffff80000000.
I thought you were going to write a update to recordmcount.c to handle this at compile time?
-- Steve
> > Signed-off-by: Thomas Garnier <thgarnie@google.com> > --- >
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