Messages in this thread |  | | Date | Thu, 14 Nov 2013 13:07:35 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v2] ftrace/x86: Load ftrace_ops in parameter not the variable holding it |
| |
(2013/11/14 5:20), Steven Rostedt wrote: > > Function tracing callbacks expect to have the ftrace_ops that registered it > passed to them, not the address of the variable that holds the ftrace_ops > that registered it. > > Use a mov instead of a lea to store the ftrace_ops into the parameter > of the function tracing callback.
I see, function_trace_op is just a pointer to an actual ftrace_ops. :) And I have ensured this change doesn't affect ftrace-kprobes since it doesn't use this parameter.
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Thank you,
> --- > arch/x86/kernel/entry_32.S | 4 ++-- > arch/x86/kernel/entry_64.S | 2 +- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S > index f0dcb0c..15a569a 100644 > --- a/arch/x86/kernel/entry_32.S > +++ b/arch/x86/kernel/entry_32.S > @@ -1085,7 +1085,7 @@ ENTRY(ftrace_caller) > pushl $0 /* Pass NULL as regs pointer */ > movl 4*4(%esp), %eax > movl 0x4(%ebp), %edx > - leal function_trace_op, %ecx > + movl function_trace_op, %ecx > subl $MCOUNT_INSN_SIZE, %eax > > .globl ftrace_call > @@ -1143,7 +1143,7 @@ ENTRY(ftrace_regs_caller) > movl 12*4(%esp), %eax /* Load ip (1st parameter) */ > subl $MCOUNT_INSN_SIZE, %eax /* Adjust ip */ > movl 0x4(%ebp), %edx /* Load parent ip (2nd parameter) */ > - leal function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */ > + movl function_trace_op, %ecx /* Save ftrace_pos in 3rd parameter */ > pushl %esp /* Save pt_regs as 4th parameter */ > > GLOBAL(ftrace_regs_call) > diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S > index b077f4c..9ce2567 100644 > --- a/arch/x86/kernel/entry_64.S > +++ b/arch/x86/kernel/entry_64.S > @@ -88,7 +88,7 @@ END(function_hook) > MCOUNT_SAVE_FRAME \skip > > /* Load the ftrace_ops into the 3rd parameter */ > - leaq function_trace_op, %rdx > + movq function_trace_op(%rip), %rdx > > /* Load ip into the first parameter */ > movq RIP(%rsp), %rdi >
-- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
|  |