On Thu, 2012-08-09 at 09:46 -0400, Steven Rostedt wrote: > Peter and Masami > > During my final tests, I found that this change breaks the > !DYNAMIC_FTRACE config. That is, when we don't do the run-time updates > of mcount calls to nops, the compiler will use fentry but the code still > uses mcount. > > I fixed this in the patch below. But as you two have acked and reviewed > it, I can't add your tags if I have changed the code. Can you ack/review > it again. > > Thanks! >
This is the changes that were made against the original patch: diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 2add3bb..a698521 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -68,18 +68,19 @@ .section .entry.text, "ax" #ifdef CONFIG_FUNCTION_TRACER -#ifdef CONFIG_DYNAMIC_FTRACE #ifdef CC_USING_FENTRY -ENTRY(__fentry__) - retq -END(__fentry__) +# define function_hook __fentry__ #else -ENTRY(mcount) - retq -END(mcount) +# define function_hook mcount #endif +#ifdef CONFIG_DYNAMIC_FTRACE + +ENTRY(function_hook) + retq +END(function_hook) + /* skip is set if stack has been adjusted */ .macro ftrace_caller_setup skip=0 MCOUNT_SAVE_FRAME \skip @@ -188,7 +189,8 @@ END(ftrace_regs_caller) #else /* ! CONFIG_DYNAMIC_FTRACE */ -ENTRY(mcount) + +ENTRY(function_hook) cmpl $0, function_trace_stop jne ftrace_stub @@ -210,7 +212,11 @@ trace: MCOUNT_SAVE_FRAME movq RIP(%rsp), %rdi +#ifdef CC_USING_FENTRY + movq SS+16(%rsp), %rsi +#else movq 8(%rbp), %rsi +#endif subq $MCOUNT_INSN_SIZE, %rdi call *ftrace_trace_function @@ -218,7 +224,7 @@ trace: MCOUNT_RESTORE_FRAME jmp ftrace_stub -END(mcount) +END(function_hook) #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_TRACER */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/