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 v8 08/16] init: lto: fix PREL32 relocations Date: Tue, 1 Dec 2020 13:36:59 -0800 [thread overview] Message-ID: <20201201213707.541432-9-samitolvanen@google.com> (raw) In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> With LTO, the compiler can rename static functions to avoid global naming collisions. As initcall functions are typically static, renaming can break references to them in inline assembly. This change adds a global stub with a stable name for each initcall to fix the issue when PREL32 relocations are used. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> --- include/linux/init.h | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/include/linux/init.h b/include/linux/init.h index d466bea7ecba..27b9478dcdef 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -209,26 +209,49 @@ extern bool initcall_debug; */ #define __initcall_section(__sec, __iid) \ #__sec ".init.." #__iid + +/* + * With LTO, the compiler can rename static functions to avoid + * global naming collisions. We use a global stub function for + * initcalls to create a stable symbol name whose address can be + * taken in inline assembly when PREL32 relocations are used. + */ +#define __initcall_stub(fn, __iid, id) \ + __initcall_name(initstub, __iid, id) + +#define __define_initcall_stub(__stub, fn) \ + int __init __stub(void); \ + int __init __stub(void) \ + { \ + return fn(); \ + } \ + __ADDRESSABLE(__stub) #else #define __initcall_section(__sec, __iid) \ #__sec ".init" + +#define __initcall_stub(fn, __iid, id) fn + +#define __define_initcall_stub(__stub, fn) \ + __ADDRESSABLE(fn) #endif #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS -#define ____define_initcall(fn, __name, __sec) \ - __ADDRESSABLE(fn) \ +#define ____define_initcall(fn, __stub, __name, __sec) \ + __define_initcall_stub(__stub, fn) \ asm(".section \"" __sec "\", \"a\" \n" \ __stringify(__name) ": \n" \ - ".long " #fn " - . \n" \ + ".long " __stringify(__stub) " - . \n" \ ".previous \n"); #else -#define ____define_initcall(fn, __name, __sec) \ +#define ____define_initcall(fn, __unused, __name, __sec) \ static initcall_t __name __used \ __attribute__((__section__(__sec))) = fn; #endif #define __unique_initcall(fn, id, __sec, __iid) \ ____define_initcall(fn, \ + __initcall_stub(fn, __iid, id), \ __initcall_name(initcall, __iid, id), \ __initcall_section(__sec, __iid)) -- 2.29.2.576.ga3fc446d84-goog
WARNING: multiple messages have this Message-ID (diff)
From: Sami Tolvanen <samitolvanen@google.com> To: Masahiro Yamada <masahiroy@kernel.org>, Steven Rostedt <rostedt@goodmis.org>, Will Deacon <will@kernel.org> Cc: linux-arch@vger.kernel.org, Kees Cook <keescook@chromium.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, linux-pci@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen <samitolvanen@google.com>, Josh Poimboeuf <jpoimboe@redhat.com>, linux-arm-kernel@lists.infradead.org Subject: [PATCH v8 08/16] init: lto: fix PREL32 relocations Date: Tue, 1 Dec 2020 13:36:59 -0800 [thread overview] Message-ID: <20201201213707.541432-9-samitolvanen@google.com> (raw) In-Reply-To: <20201201213707.541432-1-samitolvanen@google.com> With LTO, the compiler can rename static functions to avoid global naming collisions. As initcall functions are typically static, renaming can break references to them in inline assembly. This change adds a global stub with a stable name for each initcall to fix the issue when PREL32 relocations are used. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> --- include/linux/init.h | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/include/linux/init.h b/include/linux/init.h index d466bea7ecba..27b9478dcdef 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -209,26 +209,49 @@ extern bool initcall_debug; */ #define __initcall_section(__sec, __iid) \ #__sec ".init.." #__iid + +/* + * With LTO, the compiler can rename static functions to avoid + * global naming collisions. We use a global stub function for + * initcalls to create a stable symbol name whose address can be + * taken in inline assembly when PREL32 relocations are used. + */ +#define __initcall_stub(fn, __iid, id) \ + __initcall_name(initstub, __iid, id) + +#define __define_initcall_stub(__stub, fn) \ + int __init __stub(void); \ + int __init __stub(void) \ + { \ + return fn(); \ + } \ + __ADDRESSABLE(__stub) #else #define __initcall_section(__sec, __iid) \ #__sec ".init" + +#define __initcall_stub(fn, __iid, id) fn + +#define __define_initcall_stub(__stub, fn) \ + __ADDRESSABLE(fn) #endif #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS -#define ____define_initcall(fn, __name, __sec) \ - __ADDRESSABLE(fn) \ +#define ____define_initcall(fn, __stub, __name, __sec) \ + __define_initcall_stub(__stub, fn) \ asm(".section \"" __sec "\", \"a\" \n" \ __stringify(__name) ": \n" \ - ".long " #fn " - . \n" \ + ".long " __stringify(__stub) " - . \n" \ ".previous \n"); #else -#define ____define_initcall(fn, __name, __sec) \ +#define ____define_initcall(fn, __unused, __name, __sec) \ static initcall_t __name __used \ __attribute__((__section__(__sec))) = fn; #endif #define __unique_initcall(fn, id, __sec, __iid) \ ____define_initcall(fn, \ + __initcall_stub(fn, __iid, id), \ __initcall_name(initcall, __iid, id), \ __initcall_section(__sec, __iid)) -- 2.29.2.576.ga3fc446d84-goog _______________________________________________ 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:[~2020-12-01 21:39 UTC|newest] Thread overview: 141+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-12-01 21:36 [PATCH v8 00/16] Add support for Clang LTO Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` [PATCH v8 01/16] tracing: move function tracer options to Kconfig Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:47 ` Steven Rostedt 2020-12-01 21:47 ` Steven Rostedt 2020-12-01 21:36 ` [PATCH v8 02/16] kbuild: add support for Clang LTO Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-02 2:59 ` Masahiro Yamada 2020-12-02 2:59 ` Masahiro Yamada 2020-12-03 0:07 ` Nick Desaulniers 2020-12-03 0:07 ` Nick Desaulniers 2020-12-03 0:07 ` Nick Desaulniers 2020-12-01 21:36 ` [PATCH v8 03/16] kbuild: lto: fix module versioning Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` [PATCH v8 04/16] kbuild: lto: limit inlining Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` [PATCH v8 05/16] kbuild: lto: merge module sections Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` [PATCH v8 06/16] kbuild: lto: remove duplicate dependencies from .mod files Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` [PATCH v8 07/16] init: lto: ensure initcall ordering Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen [this message] 2020-12-01 21:36 ` [PATCH v8 08/16] init: lto: fix PREL32 relocations Sami Tolvanen 2020-12-01 21:36 ` Sami Tolvanen 2020-12-01 21:37 ` [PATCH v8 09/16] PCI: Fix PREL32 relocations for LTO Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` [PATCH v8 10/16] modpost: lto: strip .lto from module names Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` [PATCH v8 11/16] scripts/mod: disable LTO for empty.c Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` [PATCH v8 12/16] efi/libstub: disable LTO Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` [PATCH v8 13/16] drivers/misc/lkdtm: disable LTO for rodata.o Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` [PATCH v8 14/16] arm64: vdso: disable LTO Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` [PATCH v8 15/16] arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` [PATCH v8 16/16] arm64: allow LTO to be selected Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-01 21:37 ` Sami Tolvanen 2020-12-03 0:01 ` [PATCH v8 00/16] Add support for Clang LTO Nick Desaulniers 2020-12-03 0:01 ` Nick Desaulniers 2020-12-03 0:01 ` Nick Desaulniers 2020-12-03 11:26 ` Will Deacon 2020-12-03 11:26 ` Will Deacon 2020-12-03 17:07 ` Sami Tolvanen 2020-12-03 17:07 ` Sami Tolvanen 2020-12-03 17:07 ` Sami Tolvanen 2020-12-03 18:21 ` Nathan Chancellor 2020-12-03 18:21 ` Nathan Chancellor 2020-12-03 18:22 ` Will Deacon 2020-12-03 18:22 ` Will Deacon 2020-12-03 22:32 ` Nick Desaulniers 2020-12-03 22:32 ` Nick Desaulniers 2020-12-03 22:32 ` Nick Desaulniers 2020-12-04 9:35 ` Will Deacon 2020-12-04 9:35 ` Will Deacon 2020-12-04 22:52 ` Sami Tolvanen 2020-12-04 22:52 ` Sami Tolvanen 2020-12-04 22:52 ` Sami Tolvanen 2020-12-06 6:50 ` Nathan Chancellor 2020-12-06 6:50 ` Nathan Chancellor 2020-12-06 20:09 ` Sami Tolvanen 2020-12-06 20:09 ` Sami Tolvanen 2020-12-06 20:09 ` Sami Tolvanen 2020-12-08 0:46 ` Nathan Chancellor 2020-12-08 0:46 ` Nathan Chancellor 2020-12-08 12:15 ` Arnd Bergmann 2020-12-08 12:15 ` Arnd Bergmann 2020-12-08 12:15 ` Arnd Bergmann 2020-12-08 13:54 ` Arnd Bergmann 2020-12-08 13:54 ` Arnd Bergmann 2020-12-08 13:54 ` Arnd Bergmann 2020-12-08 16:53 ` Sami Tolvanen 2020-12-08 16:53 ` Sami Tolvanen 2020-12-08 16:53 ` Sami Tolvanen 2020-12-08 16:56 ` Arnd Bergmann 2020-12-08 16:56 ` Arnd Bergmann 2020-12-08 16:56 ` Arnd Bergmann 2020-12-08 16:43 ` Sami Tolvanen 2020-12-08 16:43 ` Sami Tolvanen 2020-12-08 16:43 ` Sami Tolvanen 2020-12-08 20:59 ` Arnd Bergmann 2020-12-08 20:59 ` Arnd Bergmann 2020-12-08 21:02 ` Arnd Bergmann 2020-12-08 21:02 ` Arnd Bergmann 2020-12-09 5:23 ` Fāng-ruì Sòng 2020-12-09 5:23 ` Fāng-ruì Sòng 2020-12-09 5:23 ` Fāng-ruì Sòng 2020-12-09 9:07 ` Arnd Bergmann 2020-12-09 9:07 ` Arnd Bergmann 2020-12-09 9:07 ` Arnd Bergmann 2020-12-09 9:59 ` Arnd Bergmann 2020-12-09 9:59 ` Arnd Bergmann 2020-12-09 16:09 ` Sami Tolvanen 2020-12-09 16:09 ` Sami Tolvanen 2020-12-09 16:09 ` Sami Tolvanen 2020-12-09 19:24 ` Arnd Bergmann 2020-12-09 19:24 ` Arnd Bergmann 2020-12-09 19:24 ` Arnd Bergmann 2020-12-08 21:09 ` Nick Desaulniers 2020-12-08 21:09 ` Nick Desaulniers 2020-12-08 21:09 ` Nick Desaulniers 2020-12-08 22:20 ` Arnd Bergmann 2020-12-08 22:20 ` Arnd Bergmann 2020-12-08 22:20 ` Arnd Bergmann 2020-12-09 16:11 ` Sami Tolvanen 2020-12-09 16:11 ` Sami Tolvanen 2020-12-09 16:11 ` Sami Tolvanen 2020-12-09 4:55 ` Fangrui Song 2020-12-09 4:55 ` Fangrui Song 2020-12-09 9:19 ` Arnd Bergmann 2020-12-09 9:19 ` Arnd Bergmann 2020-12-09 9:19 ` Arnd Bergmann 2020-12-09 12:35 ` Arnd Bergmann 2020-12-09 12:35 ` Arnd Bergmann 2020-12-09 12:35 ` Arnd Bergmann 2020-12-09 16:25 ` Sami Tolvanen 2020-12-09 16:25 ` Sami Tolvanen 2020-12-09 16:25 ` Sami Tolvanen 2020-12-09 17:51 ` Arnd Bergmann 2020-12-09 17:51 ` Arnd Bergmann 2020-12-09 17:51 ` Arnd Bergmann
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