The following commit has been merged into the x86/core branch of tip: Commit-ID: eac828eaef295cd0cc8b58f55fa5c8401fdc2370 Gitweb: https://git.kernel.org/tip/eac828eaef295cd0cc8b58f55fa5c8401fdc2370 Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> AuthorDate: Thu, 15 Sep 2022 13:11:35 +02:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Mon, 17 Oct 2022 16:41:18 +02:00 x86/ftrace: Remove ftrace_epilogue() Remove the weird jumps to RET and simply use RET. This then promotes ftrace_stub() to a real function; which becomes important for kcfi. Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220915111148.719080593@xxxxxxxxxxxxx --- arch/x86/kernel/ftrace_64.S | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S index dfeb227..a90c55a 100644 --- a/arch/x86/kernel/ftrace_64.S +++ b/arch/x86/kernel/ftrace_64.S @@ -172,20 +172,14 @@ SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL) */ SYM_INNER_LABEL(ftrace_caller_end, SYM_L_GLOBAL) ANNOTATE_NOENDBR - - jmp ftrace_epilogue + RET SYM_FUNC_END(ftrace_caller); STACK_FRAME_NON_STANDARD_FP(ftrace_caller) -SYM_FUNC_START(ftrace_epilogue) -/* - * This is weak to keep gas from relaxing the jumps. - */ -SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK) +SYM_FUNC_START(ftrace_stub) UNWIND_HINT_FUNC - ENDBR RET -SYM_FUNC_END(ftrace_epilogue) +SYM_FUNC_END(ftrace_stub) SYM_FUNC_START(ftrace_regs_caller) /* Save the current flags before any operations that can change them */ @@ -262,14 +256,11 @@ SYM_INNER_LABEL(ftrace_regs_caller_jmp, SYM_L_GLOBAL) popfq /* - * As this jmp to ftrace_epilogue can be a short jump - * it must not be copied into the trampoline. - * The trampoline will add the code to jump - * to the return. + * The trampoline will add the return. */ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL) ANNOTATE_NOENDBR - jmp ftrace_epilogue + RET /* Swap the flags with orig_rax */ 1: movq MCOUNT_REG_SIZE(%rsp), %rdi @@ -280,7 +271,7 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL) /* Restore flags */ popfq UNWIND_HINT_FUNC - jmp ftrace_epilogue + RET SYM_FUNC_END(ftrace_regs_caller) STACK_FRAME_NON_STANDARD_FP(ftrace_regs_caller)
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