On Mon, Mar 23, 2020 at 08:34:27AM -0700, Nathan Chancellor wrote:
On Mon, Mar 23, 2020 at 03:28:48PM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 82f2bc2fcc0160d6f82dd1ac64518ae0a4dd183f Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <natechancellor@xxxxxxxxx>
Date: Wed, 11 Mar 2020 12:41:21 -0700
Subject: [PATCH] kbuild: Disable -Wpointer-to-enum-cast
Clang's -Wpointer-to-int-cast deviates from GCC in that it warns when
casting to enums. The kernel does this in certain places, such as device
tree matches to set the version of the device being used, which allows
the kernel to avoid using a gigantic union.
https://elixir.bootlin.com/linux/v5.5.8/source/drivers/ata/ahci_brcm.c#L428
https://elixir.bootlin.com/linux/v5.5.8/source/drivers/ata/ahci_brcm.c#L402
https://elixir.bootlin.com/linux/v5.5.8/source/include/linux/mod_devicetable.h#L264
To avoid a ton of false positive warnings, disable this particular part
of the warning, which has been split off into a separate diagnostic so
that the entire warning does not need to be turned off for clang. It
will be visible under W=1 in case people want to go about fixing these
easily and enabling the warning treewide.
Cc: stable@xxxxxxxxxxxxxxx
Link: https://github.com/ClangBuiltLinux/linux/issues/887
Link: https://github.com/llvm/llvm-project/commit/2a41b31fcdfcb67ab7038fc2ffb606fd50b83a84
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index ecddf83ac142..ca08f2fe7c34 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -48,6 +48,7 @@ KBUILD_CFLAGS += -Wno-initializer-overrides
KBUILD_CFLAGS += -Wno-format
KBUILD_CFLAGS += -Wno-sign-compare
KBUILD_CFLAGS += -Wno-format-zero-length
+KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast)
endif
endif
Attached is a backport that should work for 4.4 through 4.19.
Queued up, thanks!
--
Thanks,
Sasha
