From: tip-bot for Sami Tolvanen <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
mingo@kernel.org, bp@alien8.de, npiggin@gmail.com,
tglx@linutronix.de, samitolvanen@google.com,
keescook@chromium.org, hpa@zytor.com, peterz@infradead.org,
ndesaulniers@google.com
Subject: [tip:x86/urgent] x86/build/lto: Fix truncated .bss with -fdata-sections
Date: Mon, 15 Apr 2019 23:25:21 -0700 [thread overview]
Message-ID: <tip-6a03469a1edc94da52b65478f1e00837add869a3@git.kernel.org> (raw)
In-Reply-To: <20190415164956.124067-1-samitolvanen@google.com>
Commit-ID: 6a03469a1edc94da52b65478f1e00837add869a3
Gitweb: https://git.kernel.org/tip/6a03469a1edc94da52b65478f1e00837add869a3
Author: Sami Tolvanen <samitolvanen@google.com>
AuthorDate: Mon, 15 Apr 2019 09:49:56 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 16 Apr 2019 08:20:55 +0200
x86/build/lto: Fix truncated .bss with -fdata-sections
With CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y, we compile the kernel with
-fdata-sections, which also splits the .bss section.
The new section, with a new .bss.* name, which pattern gets missed by the
main x86 linker script which only expects the '.bss' name. This results
in the discarding of the second part and a too small, truncated .bss
section and an unhappy, non-working kernel.
Use the common BSS_MAIN macro in the linker script to properly capture
and merge all the generated BSS sections.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20190415164956.124067-1-samitolvanen@google.com
[ Extended the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/vmlinux.lds.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index bad8c51fee6e..a5127b2c195f 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -362,7 +362,7 @@ SECTIONS
.bss : AT(ADDR(.bss) - LOAD_OFFSET) {
__bss_start = .;
*(.bss..page_aligned)
- *(.bss)
+ *(BSS_MAIN)
BSS_DECRYPTED
. = ALIGN(PAGE_SIZE);
__bss_stop = .;
prev parent reply other threads:[~2019-04-16 6:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-15 16:49 [PATCH] x86: fix .bss with -fdata-sections Sami Tolvanen
2019-04-15 17:33 ` Nick Desaulniers
2019-04-16 3:23 ` Kees Cook
2019-04-16 6:25 ` tip-bot for Sami Tolvanen [this message]
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