From: Nathan Chancellor <natechancellor@gmail.com>
To: gregkh@linuxfoundation.org
Cc: masahiroy@kernel.org, stable@vger.kernel.org
Subject: Re: FAILED: patch "[PATCH] kbuild: Disable -Wpointer-to-enum-cast" failed to apply to 4.19-stable tree
Date: Mon, 23 Mar 2020 08:34:27 -0700 [thread overview]
Message-ID: <20200323153427.GA40380@ubuntu-m2-xlarge-x86> (raw)
In-Reply-To: <15849737281461@kroah.com>
[-- Attachment #1: Type: text/plain, Size: 2338 bytes --]
On Mon, Mar 23, 2020 at 03:28:48PM +0100, gregkh@linuxfoundation.org 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@vger.kernel.org>.
>
> thanks,
>
> greg k-h
>
> ------------------ original commit in Linus's tree ------------------
>
> From 82f2bc2fcc0160d6f82dd1ac64518ae0a4dd183f Mon Sep 17 00:00:00 2001
> From: Nathan Chancellor <natechancellor@gmail.com>
> 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@vger.kernel.org
> Link: https://github.com/ClangBuiltLinux/linux/issues/887
> Link: https://github.com/llvm/llvm-project/commit/2a41b31fcdfcb67ab7038fc2ffb606fd50b83a84
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
>
> 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.
Cheers,
Nathan
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From 03368599bf131e92c660d884c84a648f387c89ae Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <natechancellor@gmail.com>
Date: Wed, 11 Mar 2020 12:41:21 -0700
Subject: [PATCH] kbuild: Disable -Wpointer-to-enum-cast
commit 82f2bc2fcc0160d6f82dd1ac64518ae0a4dd183f upstream.
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@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/887
Link: https://github.com/llvm/llvm-project/commit/2a41b31fcdfcb67ab7038fc2ffb606fd50b83a84
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
| 1 +
1 file changed, 1 insertion(+)
--git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 8d5357053f86..486e135d3e30 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -72,5 +72,6 @@ KBUILD_CFLAGS += $(call cc-disable-warning, format)
KBUILD_CFLAGS += $(call cc-disable-warning, sign-compare)
KBUILD_CFLAGS += $(call cc-disable-warning, format-zero-length)
KBUILD_CFLAGS += $(call cc-disable-warning, uninitialized)
+KBUILD_CFLAGS += $(call cc-disable-warning, pointer-to-enum-cast)
endif
endif
--
2.26.0
next prev parent reply other threads:[~2020-03-23 15:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-23 14:28 FAILED: patch "[PATCH] kbuild: Disable -Wpointer-to-enum-cast" failed to apply to 4.19-stable tree gregkh
2020-03-23 15:34 ` Nathan Chancellor [this message]
2020-03-23 16:36 ` Sasha Levin
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