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
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