From: "Steven Rostedt (Red Hat)" <[email protected]> Instead of having save_mcount_regs store the RIP in %rdx as a temp register to place it in the proper location of the pt_regs on the stack. Use the %rdi register as the temp register. This lets us remove the extra store in the ftrace_caller_setup macro.
Link: http://lkml.kernel.org/r/CA+55aFwF+qCGSKdGaEgW4p6N65GZ5_XTV=1nbtwdvxnd5yy...@mail.gmail.com Suggested-by: Linus Torvalds <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> --- arch/x86/kernel/mcount_64.S | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S index 0a693d011980..4f1b27642495 100644 --- a/arch/x86/kernel/mcount_64.S +++ b/arch/x86/kernel/mcount_64.S @@ -51,8 +51,8 @@ movq %r8, R8(%rsp) movq %r9, R9(%rsp) /* Move RIP to its proper location */ - movq SS+8(%rsp), %rdx - movq %rdx, RIP(%rsp) + movq SS+8(%rsp), %rdi + movq %rdi, RIP(%rsp) .endm .macro restore_mcount_regs skip=0 @@ -75,8 +75,7 @@ GLOBAL(\trace_label) /* Load the ftrace_ops into the 3rd parameter */ movq function_trace_op(%rip), %rdx - /* Load ip into the first parameter */ - movq RIP(%rsp), %rdi + /* %rdi already has %rip from the save_mcount_regs macro */ subq $MCOUNT_INSN_SIZE, %rdi /* Load the parent_ip into the second parameter */ #ifdef CC_USING_FENTRY -- 2.1.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
