From: Kees Cook <keescook@chromium.org> To: Masahiro Yamada <masahiroy@kernel.org> Cc: Sami Tolvanen <samitolvanen@google.com>, Steven Rostedt <rostedt@goodmis.org>, Will Deacon <will@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, "Paul E. McKenney" <paulmck@kernel.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, x86@kernel.org Subject: Re: [PATCH v6 14/25] kbuild: lto: remove duplicate dependencies from .mod files Date: Wed, 14 Oct 2020 15:50:28 -0700 [thread overview] Message-ID: <202010141549.412F2BF0@keescook> (raw) In-Reply-To: <20201013003203.4168817-15-samitolvanen@google.com> On Mon, Oct 12, 2020 at 05:31:52PM -0700, Sami Tolvanen wrote: > 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> Hi Masahiro, This appears to be a general improvement as well. This looks like it can land without depending on the rest of the series. -Kees > --- > scripts/Makefile.build | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/scripts/Makefile.build b/scripts/Makefile.build > index ab0ddf4884fd..96d6c9e18901 100644 > --- a/scripts/Makefile.build > +++ b/scripts/Makefile.build > @@ -266,7 +266,7 @@ 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 > -- > 2.28.0.1011.ga647a8990f-goog > -- Kees Cook
WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org> To: Masahiro Yamada <masahiroy@kernel.org> Cc: linux-arch@vger.kernel.org, x86@kernel.org, "Paul E. McKenney" <paulmck@kernel.org>, kernel-hardening@lists.openwall.com, Peter Zijlstra <peterz@infradead.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-kbuild@vger.kernel.org, Nick Desaulniers <ndesaulniers@google.com>, linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>, clang-built-linux@googlegroups.com, Sami Tolvanen <samitolvanen@google.com>, linux-pci@vger.kernel.org, Will Deacon <will@kernel.org>, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v6 14/25] kbuild: lto: remove duplicate dependencies from .mod files Date: Wed, 14 Oct 2020 15:50:28 -0700 [thread overview] Message-ID: <202010141549.412F2BF0@keescook> (raw) In-Reply-To: <20201013003203.4168817-15-samitolvanen@google.com> On Mon, Oct 12, 2020 at 05:31:52PM -0700, Sami Tolvanen wrote: > 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> Hi Masahiro, This appears to be a general improvement as well. This looks like it can land without depending on the rest of the series. -Kees > --- > scripts/Makefile.build | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/scripts/Makefile.build b/scripts/Makefile.build > index ab0ddf4884fd..96d6c9e18901 100644 > --- a/scripts/Makefile.build > +++ b/scripts/Makefile.build > @@ -266,7 +266,7 @@ 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 > -- > 2.28.0.1011.ga647a8990f-goog > -- Kees Cook _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-10-15 1:20 UTC|newest] Thread overview: 188+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-10-13 0:31 [PATCH v6 00/25] Add support for Clang LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 01/25] kbuild: preprocess module linker script Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 02/25] objtool: Add a pass for generating __mcount_loc Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 16:50 ` Ingo Molnar 2020-10-14 16:50 ` Ingo Molnar 2020-10-14 18:21 ` Peter Zijlstra 2020-10-14 18:21 ` Peter Zijlstra 2020-10-15 20:10 ` Josh Poimboeuf 2020-10-15 20:10 ` Josh Poimboeuf 2020-10-13 0:31 ` [PATCH v6 03/25] objtool: Don't autodetect vmlinux.o Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 04/25] tracing: move function tracer options to Kconfig Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 05/25] tracing: add support for objtool mcount Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 06/25] x86, build: use " Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 07/25] treewide: remove DISABLE_LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:43 ` Kees Cook 2020-10-14 22:43 ` Kees Cook 2020-10-17 1:46 ` Masahiro Yamada 2020-10-17 1:46 ` Masahiro Yamada 2020-10-13 0:31 ` [PATCH v6 08/25] kbuild: add support for Clang LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 09/25] kbuild: lto: fix module versioning Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 10/25] objtool: Split noinstr validation from --vmlinux Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 11/25] kbuild: lto: postpone objtool Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 12/25] kbuild: lto: limit inlining Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 13/25] kbuild: lto: merge module sections Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:49 ` Kees Cook 2020-10-14 22:49 ` Kees Cook 2020-10-20 16:42 ` Sami Tolvanen 2020-10-20 16:42 ` Sami Tolvanen 2020-10-20 16:42 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 14/25] kbuild: lto: remove duplicate dependencies from .mod files Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:50 ` Kees Cook [this message] 2020-10-14 22:50 ` Kees Cook 2020-12-03 17:59 ` Masahiro Yamada 2020-12-03 17:59 ` Masahiro Yamada 2020-12-03 18:47 ` Sami Tolvanen 2020-12-03 18:47 ` Sami Tolvanen 2020-12-03 18:47 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 15/25] init: lto: ensure initcall ordering Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 16/25] init: lto: fix PREL32 relocations Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:53 ` Kees Cook 2020-10-14 22:53 ` Kees Cook 2020-10-15 0:12 ` Jann Horn 2020-10-15 0:12 ` Jann Horn 2020-10-15 0:12 ` Jann Horn 2020-10-13 0:31 ` [PATCH v6 17/25] PCI: Fix PREL32 relocations for LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-14 22:58 ` Kees Cook 2020-10-14 22:58 ` Kees Cook 2020-10-13 0:31 ` [PATCH v6 18/25] modpost: lto: strip .lto from module names Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 19/25] scripts/mod: disable LTO for empty.c Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 20/25] efi/libstub: disable LTO Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` [PATCH v6 21/25] drivers/misc/lkdtm: disable LTO for rodata.o Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:31 ` Sami Tolvanen 2020-10-13 0:32 ` [PATCH v6 22/25] x86/asm: annotate indirect jumps Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-14 22:46 ` Kees Cook 2020-10-14 22:46 ` Kees Cook 2020-10-14 23:23 ` Jann Horn 2020-10-14 23:23 ` Jann Horn 2020-10-14 23:23 ` Jann Horn 2020-10-15 10:22 ` Peter Zijlstra 2020-10-15 10:22 ` Peter Zijlstra 2020-10-15 20:39 ` Josh Poimboeuf 2020-10-15 20:39 ` Josh Poimboeuf 2020-10-20 16:45 ` Sami Tolvanen 2020-10-20 16:45 ` Sami Tolvanen 2020-10-20 16:45 ` Sami Tolvanen 2020-10-20 18:52 ` Josh Poimboeuf 2020-10-20 18:52 ` Josh Poimboeuf 2020-10-20 19:24 ` Sami Tolvanen 2020-10-20 19:24 ` Sami Tolvanen 2020-10-20 19:24 ` Sami Tolvanen 2020-10-21 8:56 ` Peter Zijlstra 2020-10-21 8:56 ` Peter Zijlstra 2020-10-21 9:08 ` Peter Zijlstra 2020-10-21 9:08 ` Peter Zijlstra 2020-10-21 9:32 ` Peter Zijlstra 2020-10-21 9:32 ` Peter Zijlstra 2020-10-21 21:27 ` Josh Poimboeuf 2020-10-21 21:27 ` Josh Poimboeuf 2020-10-22 7:25 ` Peter Zijlstra 2020-10-22 7:25 ` Peter Zijlstra 2020-10-23 17:48 ` Sami Tolvanen 2020-10-23 17:48 ` Sami Tolvanen 2020-10-23 18:04 ` Nick Desaulniers 2020-10-23 18:04 ` Nick Desaulniers 2020-10-23 18:04 ` Nick Desaulniers 2020-10-21 15:01 ` Sami Tolvanen 2020-10-21 15:01 ` Sami Tolvanen 2020-10-21 15:01 ` Sami Tolvanen 2020-10-22 0:22 ` Sami Tolvanen 2020-10-22 0:22 ` Sami Tolvanen 2020-10-22 0:22 ` Sami Tolvanen 2020-10-23 17:36 ` Sami Tolvanen 2020-10-23 17:36 ` Sami Tolvanen 2020-11-09 23:11 ` Sami Tolvanen 2020-11-09 23:11 ` Sami Tolvanen 2020-11-09 23:11 ` Sami Tolvanen 2020-11-10 2:29 ` Josh Poimboeuf 2020-11-10 2:29 ` Josh Poimboeuf 2020-11-10 3:18 ` Nick Desaulniers 2020-11-10 3:18 ` Nick Desaulniers 2020-11-10 3:18 ` Nick Desaulniers 2020-11-10 4:48 ` Sami Tolvanen 2020-11-10 4:48 ` Sami Tolvanen 2020-11-10 4:48 ` Sami Tolvanen 2020-11-10 16:11 ` Josh Poimboeuf 2020-11-10 16:11 ` Josh Poimboeuf 2020-11-10 17:46 ` Josh Poimboeuf 2020-11-10 17:46 ` Josh Poimboeuf 2020-11-10 18:59 ` Sami Tolvanen 2020-11-10 18:59 ` Sami Tolvanen 2020-11-10 18:59 ` Sami Tolvanen 2020-11-13 19:54 ` Josh Poimboeuf 2020-11-13 19:54 ` Josh Poimboeuf 2020-11-13 20:24 ` Sami Tolvanen 2020-11-13 20:24 ` Sami Tolvanen 2020-11-13 20:24 ` Sami Tolvanen 2020-11-13 20:52 ` Josh Poimboeuf 2020-11-13 20:52 ` Josh Poimboeuf 2020-11-13 22:34 ` Josh Poimboeuf 2020-11-13 22:34 ` Josh Poimboeuf 2020-11-13 22:54 ` Sami Tolvanen 2020-11-13 22:54 ` Sami Tolvanen 2020-11-13 22:54 ` Sami Tolvanen 2020-11-13 22:56 ` Josh Poimboeuf 2020-11-13 22:56 ` Josh Poimboeuf 2020-11-13 23:31 ` Sami Tolvanen 2020-11-13 23:31 ` Sami Tolvanen 2020-11-13 23:31 ` Sami Tolvanen 2020-11-14 0:49 ` Josh Poimboeuf 2020-11-14 0:49 ` Josh Poimboeuf 2020-10-21 9:51 ` Peter Zijlstra 2020-10-21 9:51 ` Peter Zijlstra 2020-10-21 18:30 ` Josh Poimboeuf 2020-10-21 18:30 ` Josh Poimboeuf 2020-10-13 0:32 ` [PATCH v6 23/25] x86, vdso: disable LTO only for vDSO Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` [PATCH v6 24/25] x86, cpu: disable LTO for cpu.c Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` [PATCH v6 25/25] x86, build: allow LTO_CLANG and THINLTO to be selected Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen 2020-10-13 0:32 ` Sami Tolvanen
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