diff mbox series

[v2,2/2] kbuild: Disable CONFIG_LD_ORPHAN_WARN for ld.lld 10.0.1

Message ID 20201119204656.3261686-2-natechancellor@gmail.com (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Nathan Chancellor Nov. 19, 2020, 8:46 p.m. UTC 
ld.lld 10.0.1 spews a bunch of various warnings about .rela sections,
along with a few others. Newer versions of ld.lld do not have these
warnings. As a result, do not add '--orphan-handling=warn' to
LDFLAGS_vmlinux if ld.lld's version is not new enough.

Link: https://github.com/ClangBuiltLinux/linux/issues/1187
Link: https://github.com/ClangBuiltLinux/linux/issues/1193
Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
Reported-by: kernelci.org bot <bot@kernelci.org>
Reported-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---

v1 -> v2:

* Add condition as a depends on line (Kees Cook)

* Capture output of "$* --version" to avoid invoking linker twice (Nick
  Desaulniers)

* Improve documentation of script in comments (Nick Desaulniers)

* Pick up review tag from Kees

 MAINTAINERS            |  1 +
 init/Kconfig           |  5 +++++
 scripts/lld-version.sh | 20 ++++++++++++++++++++
 3 files changed, 26 insertions(+)
 create mode 100755 scripts/lld-version.sh

Comments

Nick Desaulniers Nov. 19, 2020, 9:13 p.m. UTC | #1 
On Thu, Nov 19, 2020 at 12:57 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> ld.lld 10.0.1 spews a bunch of various warnings about .rela sections,
> along with a few others. Newer versions of ld.lld do not have these
> warnings. As a result, do not add '--orphan-handling=warn' to
> LDFLAGS_vmlinux if ld.lld's version is not new enough.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/1187
> Link: https://github.com/ClangBuiltLinux/linux/issues/1193
> Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
> Reported-by: kernelci.org bot <bot@kernelci.org>
> Reported-by: Mark Brown <broonie@kernel.org>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

Thanks for the additions in v2.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>
> v1 -> v2:
>
> * Add condition as a depends on line (Kees Cook)
>
> * Capture output of "$* --version" to avoid invoking linker twice (Nick
>   Desaulniers)
>
> * Improve documentation of script in comments (Nick Desaulniers)
>
> * Pick up review tag from Kees
>
>  MAINTAINERS            |  1 +
>  init/Kconfig           |  5 +++++
>  scripts/lld-version.sh | 20 ++++++++++++++++++++
>  3 files changed, 26 insertions(+)
>  create mode 100755 scripts/lld-version.sh
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e451dcce054f..e6f74f130ae1 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4284,6 +4284,7 @@ B:        https://github.com/ClangBuiltLinux/linux/issues
>  C:     irc://chat.freenode.net/clangbuiltlinux
>  F:     Documentation/kbuild/llvm.rst
>  F:     scripts/clang-tools/
> +F:     scripts/lld-version.sh
>  K:     \b(?i:clang|llvm)\b
>
>  CLEANCACHE API
> diff --git a/init/Kconfig b/init/Kconfig
> index 92c58b45abb8..b9037d6c5ab3 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -47,6 +47,10 @@ config CLANG_VERSION
>         int
>         default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
>
> +config LLD_VERSION
> +       int
> +       default $(shell,$(srctree)/scripts/lld-version.sh $(LD))
> +
>  config CC_CAN_LINK
>         bool
>         default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
> @@ -1351,6 +1355,7 @@ config LD_DEAD_CODE_DATA_ELIMINATION
>  config LD_ORPHAN_WARN
>         def_bool y
>         depends on ARCH_WANT_LD_ORPHAN_WARN
> +       depends on !LD_IS_LLD || LLD_VERSION >= 110000
>         depends on $(ld-option,--orphan-handling=warn)
>
>  config SYSCTL
> diff --git a/scripts/lld-version.sh b/scripts/lld-version.sh
> new file mode 100755
> index 000000000000..d70edb4d8a4f
> --- /dev/null
> +++ b/scripts/lld-version.sh
> @@ -0,0 +1,20 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Usage: $ ./scripts/lld-version.sh ld.lld
> +#
> +# Print the linker version of `ld.lld' in a 5 or 6-digit form
> +# such as `100001' for ld.lld 10.0.1 etc.
> +
> +linker_string="$($* --version)"
> +
> +if ! ( echo $linker_string | grep -q LLD ); then
> +       echo 0
> +       exit 1
> +fi
> +
> +VERSION=$(echo $linker_string | cut -d ' ' -f 2)
> +MAJOR=$(echo $VERSION | cut -d . -f 1)
> +MINOR=$(echo $VERSION | cut -d . -f 2)
> +PATCHLEVEL=$(echo $VERSION | cut -d . -f 3)
> +printf "%d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL
> --
> 2.29.2
>
Kees Cook Nov. 24, 2020, 10:22 p.m. UTC | #2 
On Thu, Nov 19, 2020 at 01:13:27PM -0800, Nick Desaulniers wrote:
> On Thu, Nov 19, 2020 at 12:57 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > ld.lld 10.0.1 spews a bunch of various warnings about .rela sections,
> > along with a few others. Newer versions of ld.lld do not have these
> > warnings. As a result, do not add '--orphan-handling=warn' to
> > LDFLAGS_vmlinux if ld.lld's version is not new enough.
> >
> > Link: https://github.com/ClangBuiltLinux/linux/issues/1187
> > Link: https://github.com/ClangBuiltLinux/linux/issues/1193
> > Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
> > Reported-by: kernelci.org bot <bot@kernelci.org>
> > Reported-by: Mark Brown <broonie@kernel.org>
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> 
> Thanks for the additions in v2.
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

I'm going to carry this for a few days in -next, and if no one screams,
ask Linus to pull it for v5.10-rc6.

Thanks!
Masahiro Yamada Dec. 1, 2020, 1:31 p.m. UTC | #3 
On Wed, Nov 25, 2020 at 7:22 AM Kees Cook <keescook@chromium.org> wrote:
>
> On Thu, Nov 19, 2020 at 01:13:27PM -0800, Nick Desaulniers wrote:
> > On Thu, Nov 19, 2020 at 12:57 PM Nathan Chancellor
> > <natechancellor@gmail.com> wrote:
> > >
> > > ld.lld 10.0.1 spews a bunch of various warnings about .rela sections,
> > > along with a few others. Newer versions of ld.lld do not have these
> > > warnings. As a result, do not add '--orphan-handling=warn' to
> > > LDFLAGS_vmlinux if ld.lld's version is not new enough.
> > >
> > > Link: https://github.com/ClangBuiltLinux/linux/issues/1187
> > > Link: https://github.com/ClangBuiltLinux/linux/issues/1193
> > > Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
> > > Reported-by: kernelci.org bot <bot@kernelci.org>
> > > Reported-by: Mark Brown <broonie@kernel.org>
> > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> >
> > Thanks for the additions in v2.
> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
>
> I'm going to carry this for a few days in -next, and if no one screams,
> ask Linus to pull it for v5.10-rc6.
>
> Thanks!
>
> --
> Kees Cook


Sorry for the delay.
Applied to linux-kbuild.

But, I already see this in linux-next.

Please let me know if I should drop it from my tree.
Kees Cook Dec. 1, 2020, 8:56 p.m. UTC | #4 
On Tue, Dec 01, 2020 at 10:31:37PM +0900, Masahiro Yamada wrote:
> On Wed, Nov 25, 2020 at 7:22 AM Kees Cook <keescook@chromium.org> wrote:
> >
> > On Thu, Nov 19, 2020 at 01:13:27PM -0800, Nick Desaulniers wrote:
> > > On Thu, Nov 19, 2020 at 12:57 PM Nathan Chancellor
> > > <natechancellor@gmail.com> wrote:
> > > >
> > > > ld.lld 10.0.1 spews a bunch of various warnings about .rela sections,
> > > > along with a few others. Newer versions of ld.lld do not have these
> > > > warnings. As a result, do not add '--orphan-handling=warn' to
> > > > LDFLAGS_vmlinux if ld.lld's version is not new enough.
> > > >
> > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1187
> > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1193
> > > > Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
> > > > Reported-by: kernelci.org bot <bot@kernelci.org>
> > > > Reported-by: Mark Brown <broonie@kernel.org>
> > > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > > > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> > >
> > > Thanks for the additions in v2.
> > > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> >
> > I'm going to carry this for a few days in -next, and if no one screams,
> > ask Linus to pull it for v5.10-rc6.
> >
> > Thanks!
> >
> > --
> > Kees Cook
> 
> 
> Sorry for the delay.
> Applied to linux-kbuild.

Great, thanks!

> But, I already see this in linux-next.
> Please let me know if I should drop it from my tree.

My intention was to get this to Linus this week. Do you want to do that
yourself, or Ack the patches in my tree and I'll send it?

-Kees
Masahiro Yamada Dec. 2, 2020, 2:37 a.m. UTC | #5 
On Wed, Dec 2, 2020 at 5:56 AM Kees Cook <keescook@chromium.org> wrote:
>
> On Tue, Dec 01, 2020 at 10:31:37PM +0900, Masahiro Yamada wrote:
> > On Wed, Nov 25, 2020 at 7:22 AM Kees Cook <keescook@chromium.org> wrote:
> > >
> > > On Thu, Nov 19, 2020 at 01:13:27PM -0800, Nick Desaulniers wrote:
> > > > On Thu, Nov 19, 2020 at 12:57 PM Nathan Chancellor
> > > > <natechancellor@gmail.com> wrote:
> > > > >
> > > > > ld.lld 10.0.1 spews a bunch of various warnings about .rela sections,
> > > > > along with a few others. Newer versions of ld.lld do not have these
> > > > > warnings. As a result, do not add '--orphan-handling=warn' to
> > > > > LDFLAGS_vmlinux if ld.lld's version is not new enough.
> > > > >
> > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1187
> > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1193
> > > > > Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
> > > > > Reported-by: kernelci.org bot <bot@kernelci.org>
> > > > > Reported-by: Mark Brown <broonie@kernel.org>
> > > > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > > > > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> > > >
> > > > Thanks for the additions in v2.
> > > > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > >
> > > I'm going to carry this for a few days in -next, and if no one screams,
> > > ask Linus to pull it for v5.10-rc6.
> > >
> > > Thanks!
> > >
> > > --
> > > Kees Cook
> >
> >
> > Sorry for the delay.
> > Applied to linux-kbuild.
>
> Great, thanks!
>
> > But, I already see this in linux-next.
> > Please let me know if I should drop it from my tree.
>
> My intention was to get this to Linus this week. Do you want to do that
> yourself, or Ack the patches in my tree and I'll send it?
>
> -Kees
>
> --
> Kees Cook


I will send a kbuild pull request myself this week.
Kees Cook Dec. 2, 2020, 6:56 p.m. UTC | #6 
On Wed, Dec 02, 2020 at 11:37:38AM +0900, Masahiro Yamada wrote:
> On Wed, Dec 2, 2020 at 5:56 AM Kees Cook <keescook@chromium.org> wrote:
> >
> > On Tue, Dec 01, 2020 at 10:31:37PM +0900, Masahiro Yamada wrote:
> > > On Wed, Nov 25, 2020 at 7:22 AM Kees Cook <keescook@chromium.org> wrote:
> > > >
> > > > On Thu, Nov 19, 2020 at 01:13:27PM -0800, Nick Desaulniers wrote:
> > > > > On Thu, Nov 19, 2020 at 12:57 PM Nathan Chancellor
> > > > > <natechancellor@gmail.com> wrote:
> > > > > >
> > > > > > ld.lld 10.0.1 spews a bunch of various warnings about .rela sections,
> > > > > > along with a few others. Newer versions of ld.lld do not have these
> > > > > > warnings. As a result, do not add '--orphan-handling=warn' to
> > > > > > LDFLAGS_vmlinux if ld.lld's version is not new enough.
> > > > > >
> > > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1187
> > > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1193
> > > > > > Reported-by: Arvind Sankar <nivedita@alum.mit.edu>
> > > > > > Reported-by: kernelci.org bot <bot@kernelci.org>
> > > > > > Reported-by: Mark Brown <broonie@kernel.org>
> > > > > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > > > > > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> > > > >
> > > > > Thanks for the additions in v2.
> > > > > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > > >
> > > > I'm going to carry this for a few days in -next, and if no one screams,
> > > > ask Linus to pull it for v5.10-rc6.
> > > >
> > > > Thanks!
> > > >
> > > > --
> > > > Kees Cook
> > >
> > >
> > > Sorry for the delay.
> > > Applied to linux-kbuild.
> >
> > Great, thanks!
> >
> > > But, I already see this in linux-next.
> > > Please let me know if I should drop it from my tree.
> >
> > My intention was to get this to Linus this week. Do you want to do that
> > yourself, or Ack the patches in my tree and I'll send it?
> 
> I will send a kbuild pull request myself this week.

Okay, thanks! I've removed it from my -next tree now.
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index e451dcce054f..e6f74f130ae1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4284,6 +4284,7 @@  B:	https://github.com/ClangBuiltLinux/linux/issues
 C:	irc://chat.freenode.net/clangbuiltlinux
 F:	Documentation/kbuild/llvm.rst
 F:	scripts/clang-tools/
+F:	scripts/lld-version.sh
 K:	\b(?i:clang|llvm)\b
 
 CLEANCACHE API
diff --git a/init/Kconfig b/init/Kconfig
index 92c58b45abb8..b9037d6c5ab3 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -47,6 +47,10 @@  config CLANG_VERSION
 	int
 	default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
 
+config LLD_VERSION
+	int
+	default $(shell,$(srctree)/scripts/lld-version.sh $(LD))
+
 config CC_CAN_LINK
 	bool
 	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(m64-flag)) if 64BIT
@@ -1351,6 +1355,7 @@  config LD_DEAD_CODE_DATA_ELIMINATION
 config LD_ORPHAN_WARN
 	def_bool y
 	depends on ARCH_WANT_LD_ORPHAN_WARN
+	depends on !LD_IS_LLD || LLD_VERSION >= 110000
 	depends on $(ld-option,--orphan-handling=warn)
 
 config SYSCTL
diff --git a/scripts/lld-version.sh b/scripts/lld-version.sh
new file mode 100755
index 000000000000..d70edb4d8a4f
--- /dev/null
+++ b/scripts/lld-version.sh
@@ -0,0 +1,20 @@ 
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Usage: $ ./scripts/lld-version.sh ld.lld
+#
+# Print the linker version of `ld.lld' in a 5 or 6-digit form
+# such as `100001' for ld.lld 10.0.1 etc.
+
+linker_string="$($* --version)"
+
+if ! ( echo $linker_string | grep -q LLD ); then
+	echo 0
+	exit 1
+fi
+
+VERSION=$(echo $linker_string | cut -d ' ' -f 2)
+MAJOR=$(echo $VERSION | cut -d . -f 1)
+MINOR=$(echo $VERSION | cut -d . -f 2)
+PATCHLEVEL=$(echo $VERSION | cut -d . -f 3)
+printf "%d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL