Disable the __builtin_return_address() warning globally after all

This affectively reverts commit a1e76d27ea6e ("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 <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Makefile b/Makefile
index addb235b537c70e3672fcef15c9ad9cc01c6da84..27f97b53e6ebd4e60407d38e13be42a0d2fe7127 100644 (file)
--- 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 992ab9d99f3576620625d1b0d2011f22e0eadfd4..e5798084554911440844e1757c9ee656dc40cf12 100644 (file)
--- 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 2ca1faf3fa09038feaeea4fb4adbe5ea6717df30..295bd7a9f76bbb292d68f088546dc220231458d4 100644 (file)
--- 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 \