From: David Gow <davidgow@google.com>
To: Kees Cook <keescook@chromium.org>
Cc: David Gow <davidgow@google.com>, Jeff Dike <jdike@addtoit.com>,
Richard Weinberger <richard@nod.at>,
Anton Ivanov <anton.ivanov@cambridgegreys.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Nathan Chancellor <nathan@kernel.org>,
linux-um@lists.infradead.org, linux-kbuild@vger.kernel.org,
linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com,
llvm@lists.linux.dev, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH] um: clang: Strip out -mno-global-merge from USER_CFLAGS
Date: Thu, 3 Mar 2022 17:06:42 +0800 [thread overview]
Message-ID: <20220303090643.241747-1-davidgow@google.com> (raw)
The things built with USER_CFLAGS don't seem to recognise it as a
compiler option, and print a warning:
clang: warning: argument unused during compilation: '-mno-global-merge' [-Wunused-command-line-argument]
Fixes: 744814d2fa ("um: Allow builds with Clang")
Signed-off-by: David Gow <davidgow@google.com>
---
This warning shows up after merging:
https://lore.kernel.org/lkml/20220227184517.504931-6-keescook@chromium.org/
I'm not 100% sure why this is necessary, but it does seem to work. All
the attempts to get rid of -mno-global-merge entirely have been met with
skepticism, but I'm guessing that it's not a problem for just the UML
"user" files, as they shouldn't(?) interact too much with modules.
arch/um/Makefile | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/um/Makefile b/arch/um/Makefile
index f2fe63bfd819..320b09cd513c 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -75,6 +75,10 @@ USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \
-D_FILE_OFFSET_BITS=64 -idirafter $(srctree)/include \
-idirafter $(objtree)/include -D__KERNEL__ -D__UM_HOST__
+ifdef CONFIG_CC_IS_CLANG
+USER_CFLAGS := $(patsubst -mno-global-merge,,$(USER_CFLAGS))
+endif
+
#This will adjust *FLAGS accordingly to the platform.
include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
--
2.35.1.616.g0bdcbb4464-goog
WARNING: multiple messages have this Message-ID (diff)
From: David Gow <davidgow@google.com>
To: Kees Cook <keescook@chromium.org>
Cc: David Gow <davidgow@google.com>, Jeff Dike <jdike@addtoit.com>,
Richard Weinberger <richard@nod.at>,
Anton Ivanov <anton.ivanov@cambridgegreys.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Nathan Chancellor <nathan@kernel.org>,
linux-um@lists.infradead.org, linux-kbuild@vger.kernel.org,
linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com,
llvm@lists.linux.dev, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH] um: clang: Strip out -mno-global-merge from USER_CFLAGS
Date: Thu, 3 Mar 2022 17:06:42 +0800 [thread overview]
Message-ID: <20220303090643.241747-1-davidgow@google.com> (raw)
The things built with USER_CFLAGS don't seem to recognise it as a
compiler option, and print a warning:
clang: warning: argument unused during compilation: '-mno-global-merge' [-Wunused-command-line-argument]
Fixes: 744814d2fa ("um: Allow builds with Clang")
Signed-off-by: David Gow <davidgow@google.com>
---
This warning shows up after merging:
https://lore.kernel.org/lkml/20220227184517.504931-6-keescook@chromium.org/
I'm not 100% sure why this is necessary, but it does seem to work. All
the attempts to get rid of -mno-global-merge entirely have been met with
skepticism, but I'm guessing that it's not a problem for just the UML
"user" files, as they shouldn't(?) interact too much with modules.
arch/um/Makefile | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/um/Makefile b/arch/um/Makefile
index f2fe63bfd819..320b09cd513c 100644
--- a/arch/um/Makefile
+++ b/arch/um/Makefile
@@ -75,6 +75,10 @@ USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \
-D_FILE_OFFSET_BITS=64 -idirafter $(srctree)/include \
-idirafter $(objtree)/include -D__KERNEL__ -D__UM_HOST__
+ifdef CONFIG_CC_IS_CLANG
+USER_CFLAGS := $(patsubst -mno-global-merge,,$(USER_CFLAGS))
+endif
+
#This will adjust *FLAGS accordingly to the platform.
include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
--
2.35.1.616.g0bdcbb4464-goog
_______________________________________________
linux-um mailing list
linux-um@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-um
next reply other threads:[~2022-03-03 9:06 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-03 9:06 David Gow [this message]
2022-03-03 9:06 ` [PATCH] um: clang: Strip out -mno-global-merge from USER_CFLAGS David Gow
2022-03-03 17:30 ` Nathan Chancellor
2022-03-03 17:30 ` Nathan Chancellor
2022-03-03 18:04 ` Kees Cook
2022-03-03 18:26 ` Nathan Chancellor
2022-03-03 18:26 ` Nathan Chancellor
2022-03-03 18:39 ` Nick Desaulniers
2022-03-03 18:39 ` Nick Desaulniers
2022-03-04 11:42 ` Sedat Dilek
2022-03-04 11:42 ` Sedat Dilek
2022-03-04 6:51 ` David Gow
2022-03-04 6:51 ` David Gow
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220303090643.241747-1-davidgow@google.com \
--to=davidgow@google.com \
--cc=anton.ivanov@cambridgegreys.com \
--cc=jdike@addtoit.com \
--cc=keescook@chromium.org \
--cc=kunit-dev@googlegroups.com \
--cc=linux-hardening@vger.kernel.org \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-um@lists.infradead.org \
--cc=llvm@lists.linux.dev \
--cc=masahiroy@kernel.org \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=richard@nod.at \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.