path: root/Makefile
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authorSteven Rostedt <>2016-07-28 22:30:43 -0400
committerSteven Rostedt <>2016-08-02 12:57:48 -0400
commit377ccbb483738f84400ddf5840c7dd8825716985 (patch)
tree6e124d8704f768251cf65bc2b4c8e5dc5b11f679 /Makefile
parentb2e1c26f0b62531636509fbcb6dab65617ed8331 (diff)
Makefile: Mute warning for __builtin_return_address(>0) for tracing only
With the latest gcc compilers, they give a warning if __builtin_return_address() parameter is greater than 0. That is because if it is used by a function called by a top level function (or in the case of the kernel, by assembly), it can try to access stack frames outside the stack and crash the system. The tracing system uses __builtin_return_address() of up to 2! But it is well aware of the dangers that it may have, and has even added precautions to protect against it (see the thunk code in arch/x86/entry/thunk*.S) Linus originally added KBUILD_CFLAGS that would suppress the warning for the entire kernel, as simply adding KBUILD_CFLAGS to the tracing directory wouldn't work. The tracing directory plays a bit with the CFLAGS and requires a little more logic. This adds that special logic to only suppress the warning for the tracing directory. If it is used anywhere else outside of tracing, the warning will still be triggered. Link: Tested-by: Linus Torvalds <> Signed-off-by: Steven Rostedt <>
Diffstat (limited to 'Makefile')
1 files changed, 0 insertions, 1 deletions
diff --git a/Makefile b/Makefile
index 393b6159ae92..d384848478b9 100644
--- a/Makefile
+++ b/Makefile
@@ -620,7 +620,6 @@ 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,)