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 v9 05/16] kbuild: lto: merge module sections
Date: Fri, 11 Dec 2020 10:46:22 -0800 [thread overview]
Message-ID: <20201211184633.3213045-6-samitolvanen@google.com> (raw)
In-Reply-To: <20201211184633.3213045-1-samitolvanen@google.com>
LLD always splits sections with LTO, which increases module sizes. This
change adds linker script rules to merge the split sections in the final
module.
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
scripts/module.lds.S | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index 69b9b71a6a47..18d5b8423635 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -23,6 +23,30 @@ SECTIONS {
.init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
__jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }
+
+ __patchable_function_entries : { *(__patchable_function_entries) }
+
+ /*
+ * With CONFIG_LTO_CLANG, LLD always enables -fdata-sections and
+ * -ffunction-sections, which increases the size of the final module.
+ * Merge the split sections in the final binary.
+ */
+ .bss : {
+ *(.bss .bss.[0-9a-zA-Z_]*)
+ *(.bss..L*)
+ }
+
+ .data : {
+ *(.data .data.[0-9a-zA-Z_]*)
+ *(.data..L*)
+ }
+
+ .rodata : {
+ *(.rodata .rodata.[0-9a-zA-Z_]*)
+ *(.rodata..L*)
+ }
+
+ .text : { *(.text .text.[0-9a-zA-Z_]*) }
}
/* bring in arch-specific sections */
--
2.29.2.576.ga3fc446d84-goog
next prev parent reply other threads:[~2020-12-11 20:31 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-11 18:46 [PATCH v9 00/16] Add support for Clang LTO Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 01/16] tracing: move function tracer options to Kconfig Sami Tolvanen
2021-02-24 20:17 ` [PATCH v9 01/16] tracing: move function tracer options to Kconfig (causing parisc build failures) Guenter Roeck
2021-02-24 20:38 ` Kees Cook
2021-02-24 20:54 ` Sami Tolvanen
2021-02-24 22:29 ` Guenter Roeck
2021-02-24 22:28 ` Guenter Roeck
2021-02-24 22:42 ` Kees Cook
2020-12-11 18:46 ` [PATCH v9 02/16] kbuild: add support for Clang LTO Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 03/16] kbuild: lto: fix module versioning Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 04/16] kbuild: lto: limit inlining Sami Tolvanen
2020-12-11 18:46 ` Sami Tolvanen [this message]
2020-12-11 18:46 ` [PATCH v9 06/16] kbuild: lto: add a default list of used symbols Sami Tolvanen
2020-12-11 19:32 ` Kees Cook
2020-12-11 19:40 ` Sami Tolvanen
2020-12-11 19:45 ` Nick Desaulniers
2020-12-11 18:46 ` [PATCH v9 07/16] init: lto: ensure initcall ordering Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 08/16] init: lto: fix PREL32 relocations Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 09/16] PCI: Fix PREL32 relocations for LTO Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 10/16] modpost: lto: strip .lto from module names Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 11/16] scripts/mod: disable LTO for empty.c Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 12/16] efi/libstub: disable LTO Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 13/16] drivers/misc/lkdtm: disable LTO for rodata.o Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 14/16] arm64: vdso: disable LTO Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 15/16] arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS Sami Tolvanen
2020-12-11 18:46 ` [PATCH v9 16/16] arm64: allow LTO to be selected Sami Tolvanen
2020-12-11 19:38 ` [PATCH v9 00/16] Add support for Clang LTO Kees Cook
2021-01-09 0:27 ` Kees Cook
2021-01-09 14:54 ` Sedat Dilek
2021-01-09 15:36 ` Josh Poimboeuf
2021-01-09 15:46 ` Sedat Dilek
2021-01-09 16:07 ` Josh Poimboeuf
2021-01-09 16:21 ` Sedat Dilek
2021-01-09 16:32 ` Josh Poimboeuf
2021-01-09 16:45 ` Sedat Dilek
2021-01-09 17:03 ` Josh Poimboeuf
2021-01-09 17:05 ` Josh Poimboeuf
2021-01-09 17:33 ` Sedat Dilek
2021-01-09 23:44 ` Sedat Dilek
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=20201211184633.3213045-6-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).