From 7dc48bf96aa0fc8aa5b38cc3e5c36ac03171e680 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 15 Nov 2018 22:42:03 +0000 Subject: [PATCH] arm64: ftrace: always pass instrumented pc in x0 The core ftrace hooks take the instrumented PC in x0, but for some reason arm64's prepare_ftrace_return() takes this in x1. For consistency, let's flip the argument order and always pass the instrumented PC in x0. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: AKASHI Takahiro Cc: Ard Biesheuvel Cc: Catalin Marinas Cc: Torsten Duwe Cc: Will Deacon Signed-off-by: Will Deacon --- arch/arm64/kernel/entry-ftrace.S | 6 +++--- arch/arm64/kernel/ftrace.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S index 0cd8f828d9c3..032e24d2d554 100644 --- a/arch/arm64/kernel/entry-ftrace.S +++ b/arch/arm64/kernel/entry-ftrace.S @@ -176,10 +176,10 @@ ENDPROC(ftrace_stub) * and run return_to_handler() later on its exit. */ ENTRY(ftrace_graph_caller) - mcount_get_lr_addr x0 // pointer to function's saved lr - mcount_get_pc x1 // function's pc + mcount_get_pc x0 // function's pc + mcount_get_lr_addr x1 // pointer to function's saved lr mcount_get_parent_fp x2 // parent's fp - bl prepare_ftrace_return // prepare_ftrace_return(&lr, pc, fp) + bl prepare_ftrace_return // prepare_ftrace_return(pc, &lr, fp) mcount_exit ENDPROC(ftrace_graph_caller) diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index 2135665a8ab3..b4bd46bdc4d2 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -211,7 +211,7 @@ int __init ftrace_dyn_arch_init(void) * * Note that @frame_pointer is used only for sanity check later. */ -void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, +void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, unsigned long frame_pointer) { unsigned long return_hooker = (unsigned long)&return_to_handler; -- GitLab