From ef6000b4c6706cbb1787836442b5a74542b1809f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 12 Oct 2016 10:23:41 -0700 Subject: [PATCH] Disable the __builtin_return_address() warning globally after all This affectively reverts commit 377ccbb48373 ("Makefile: Mute warning for __builtin_return_address(>0) for tracing only") because it turns out that it really isn't tracing only - it's all over the tree. We already also had the warning disabled separately for mm/usercopy.c (which this commit also removes), and it turns out that we will also want to disable it for get_lock_parent_ip(), that is used for at least TRACE_IRQFLAGS. Which (when enabled) ends up being all over the tree. Steven Rostedt had a patch that tried to limit it to just the config options that actually triggered this, but quite frankly, the extra complexity and abstraction just isn't worth it. We have never actually had a case where the warning is actually useful, so let's just disable it globally and not worry about it. Acked-by: Steven Rostedt Cc: Thomas Gleixner Cc: Andrew Morton Cc: Ingo Molnar Cc: Peter Anvin Signed-off-by: Linus Torvalds --- Makefile | 1 + kernel/trace/Makefile | 4 ---- mm/Makefile | 3 --- 3 files changed, 1 insertion(+), 7 deletions(-) diff --git a/Makefile b/Makefile index addb235b537c..27f97b53e6eb 100644 --- a/Makefile +++ b/Makefile @@ -621,6 +621,7 @@ include arch/$(SRCARCH)/Makefile KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,) +KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,) ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE KBUILD_CFLAGS += -Os diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 992ab9d99f35..e57980845549 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -1,8 +1,4 @@ -# We are fully aware of the dangers of __builtin_return_address() -FRAME_CFLAGS := $(call cc-disable-warning,frame-address) -KBUILD_CFLAGS += $(FRAME_CFLAGS) - # Do not instrument the tracer itself: ifdef CONFIG_FUNCTION_TRACER diff --git a/mm/Makefile b/mm/Makefile index 2ca1faf3fa09..295bd7a9f76b 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -21,9 +21,6 @@ KCOV_INSTRUMENT_memcontrol.o := n KCOV_INSTRUMENT_mmzone.o := n KCOV_INSTRUMENT_vmstat.o := n -# Since __builtin_frame_address does work as used, disable the warning. -CFLAGS_usercopy.o += $(call cc-disable-warning, frame-address) - mmu-y := nommu.o mmu-$(CONFIG_MMU) := gup.o highmem.o memory.o mincore.o \ mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \ -- 2.20.1