linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sami Tolvanen <samitolvanen@google.com>
To: Masahiro Yamada <masahiroy@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Will Deacon <will@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	clang-built-linux@googlegroups.com,
	kernel-hardening@lists.openwall.com, linux-arch@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-pci@vger.kernel.org,
	Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH v7 06/17] kbuild: lto: remove duplicate dependencies from .mod files
Date: Wed, 18 Nov 2020 14:07:20 -0800	[thread overview]
Message-ID: <20201118220731.925424-7-samitolvanen@google.com> (raw)
In-Reply-To: <20201118220731.925424-1-samitolvanen@google.com>

With LTO, llvm-nm prints out symbols for each archive member
separately, which results in a lot of duplicate dependencies in the
.mod file when CONFIG_TRIM_UNUSED_SYMS is enabled. When a module
consists of several compilation units, the output can exceed the
default xargs command size limit and split the dependency list to
multiple lines, which results in used symbols getting trimmed.

This change removes duplicate dependencies, which will reduce the
probability of this happening and makes .mod files smaller and
easier to read.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
 scripts/Makefile.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index eae2f5386a03..f80ada58271d 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -281,7 +281,7 @@ endef
 
 # List module undefined symbols (or empty line if not enabled)
 ifdef CONFIG_TRIM_UNUSED_KSYMS
-cmd_undef_syms = $(NM) $< | sed -n 's/^  *U //p' | xargs echo
+cmd_undef_syms = $(NM) $< | sed -n 's/^  *U //p' | sort -u | xargs echo
 else
 cmd_undef_syms = echo
 endif
-- 
2.29.2.299.gdc1121823c-goog


  parent reply	other threads:[~2020-11-18 22:07 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-18 22:07 [PATCH v7 00/17] Add support for Clang LTO Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 01/17] tracing: move function tracer options to Kconfig Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 02/17] kbuild: add support for Clang LTO Sami Tolvanen
2020-11-18 23:48   ` Nick Desaulniers
2020-11-20 16:23     ` Sami Tolvanen
2020-11-20 19:47       ` Kees Cook
2020-11-20 20:29         ` Nathan Chancellor
2020-11-20 20:43           ` Kees Cook
2020-11-20 20:58             ` Sami Tolvanen
2020-11-20 23:59               ` Kees Cook
2020-11-21  1:46                 ` Sami Tolvanen
2020-11-21 20:11                   ` Kees Cook
2020-11-18 22:07 ` [PATCH v7 03/17] kbuild: lto: fix module versioning Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 04/17] kbuild: lto: limit inlining Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 05/17] kbuild: lto: merge module sections Sami Tolvanen
2020-11-18 22:07 ` Sami Tolvanen [this message]
2020-11-18 22:07 ` [PATCH v7 07/17] init: lto: ensure initcall ordering Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 08/17] init: lto: fix PREL32 relocations Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 09/17] PCI: Fix PREL32 relocations for LTO Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 10/17] modpost: lto: strip .lto from module names Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 11/17] scripts/mod: disable LTO for empty.c Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 12/17] efi/libstub: disable LTO Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 13/17] drivers/misc/lkdtm: disable LTO for rodata.o Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 14/17] arm64: vdso: disable LTO Sami Tolvanen
2020-11-30 11:52   ` Will Deacon
2020-11-30 23:44     ` Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 15/17] KVM: arm64: disable LTO for the nVHE directory Sami Tolvanen
2020-11-23 10:21   ` David Brazdil
2020-11-23 18:34     ` Sami Tolvanen
2020-11-18 22:07 ` [PATCH v7 16/17] arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS Sami Tolvanen
2020-11-30 11:59   ` Will Deacon
2020-11-18 22:07 ` [PATCH v7 17/17] arm64: allow LTO_CLANG and THINLTO to be selected Sami Tolvanen
2020-11-30 12:00   ` Will Deacon
2020-11-18 23:42 ` [PATCH v7 00/17] Add support for Clang LTO Nick Desaulniers
2020-11-20 10:29   ` Ard Biesheuvel
2020-11-20 20:19     ` Nick Desaulniers
2020-11-20 23:30       ` Ard Biesheuvel
2020-11-20 23:53         ` Nick Desaulniers
2020-11-21  7:35           ` Ard Biesheuvel
2020-11-21 11:40           ` Marc Zyngier
2020-11-21  3:14     ` Nathan Chancellor
2020-11-20  4:04 ` Josh Poimboeuf
2020-11-20 20:25   ` Sami Tolvanen
2020-11-30 12:01 ` Will Deacon
2020-12-01 17:31   ` Kees Cook
2020-12-01 19:51     ` Nick Desaulniers
2020-12-01 21:38       ` Sami Tolvanen
2020-12-02  2:42     ` Masahiro Yamada
2020-12-02  5:46       ` Sami Tolvanen
2020-12-02 18:54       ` Kees Cook

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=20201118220731.925424-7-samitolvanen@google.com \
    --to=samitolvanen@google.com \
    --cc=clang-built-linux@googlegroups.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jpoimboe@redhat.com \
    --cc=keescook@chromium.org \
    --cc=kernel-hardening@lists.openwall.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=masahiroy@kernel.org \
    --cc=ndesaulniers@google.com \
    --cc=paulmck@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=will@kernel.org \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).