From: Alexander Lobakin <alobakin@pm.me>
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Alexander Lobakin <alobakin@pm.me>,
Nathan Chancellor <natechancellor@gmail.com>,
Kees Cook <keescook@chromium.org>,
Fangrui Song <maskray@google.com>,
Jiaxun Yang <jiaxun.yang@flygoat.com>,
Alex Smith <alex.smith@imgtec.com>,
Ralf Baechle <ralf@linux-mips.org>,
Markos Chandras <markos.chandras@imgtec.com>,
linux-mips@vger.kernel.org, stable@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 mips-next 3/4] MIPS: vmlinux.lds.S: catch bad .got, .plt and .rel.dyn at link time
Date: Wed, 06 Jan 2021 20:08:29 +0000 [thread overview]
Message-ID: <20210106200801.31993-3-alobakin@pm.me> (raw)
In-Reply-To: <20210106200801.31993-1-alobakin@pm.me>
Catch any symbols placed in .got, .got.plt, .plt, .rel.dyn
or .rela.dyn and check for these sections to be zero-sized
at link time.
At least two of them were noticed in real builds:
mips-alpine-linux-musl-ld: warning: orphan section `.rel.dyn'
from `init/main.o' being placed in section `.rel.dyn'
ld.lld: warning: <internal>:(.got) is being placed in '.got'
Adopted from x86/kernel/vmlinux.lds.S.
Reported-by: Nathan Chancellor <natechancellor@gmail.com> # .got
Suggested-by: Fangrui Song <maskray@google.com> # .rel.dyn
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
---
arch/mips/kernel/vmlinux.lds.S | 35 ++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
index 5d6563970ab2..05eda9d9a7d5 100644
--- a/arch/mips/kernel/vmlinux.lds.S
+++ b/arch/mips/kernel/vmlinux.lds.S
@@ -227,4 +227,39 @@ SECTIONS
*(.pdr)
*(.reginfo)
}
+
+ /*
+ * Sections that should stay zero sized, which is safer to
+ * explicitly check instead of blindly discarding.
+ */
+
+ .got : {
+ *(.got)
+ *(.igot.*)
+ }
+ ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!")
+
+ .got.plt (INFO) : {
+ *(.got.plt)
+ }
+ ASSERT(SIZEOF(.got.plt) == 0, "Unexpected GOT/PLT entries detected!")
+
+ .plt : {
+ *(.plt)
+ *(.plt.*)
+ *(.iplt)
+ }
+ ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!")
+
+ .rel.dyn : {
+ *(.rel.*)
+ *(.rel_*)
+ }
+ ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!")
+
+ .rela.dyn : {
+ *(.rela.*)
+ *(.rela_*)
+ }
+ ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!")
}
--
2.30.0
next prev parent reply other threads:[~2021-01-06 20:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 20:07 [PATCH v2 mips-next 0/4] MIPS: vmlinux.lds.S sections fix & cleanup Alexander Lobakin
2021-01-06 20:08 ` [PATCH v2 mips-next 1/4] MIPS: vmlinux.lds.S: add missing PAGE_ALIGNED_DATA() section Alexander Lobakin
2021-01-06 20:08 ` [PATCH v2 mips-next 2/4] MIPS: vmlinux.lds.S: add ".gnu.attributes" to DISCARDS Alexander Lobakin
2021-01-06 22:07 ` Kees Cook
2021-01-06 22:36 ` Alexander Lobakin
2021-01-06 23:26 ` Kees Cook
2021-01-07 11:59 ` Alexander Lobakin
2021-01-06 22:43 ` Fāng-ruì Sòng
2021-01-06 20:08 ` Alexander Lobakin [this message]
2021-01-06 20:21 ` [PATCH v2 mips-next 3/4] MIPS: vmlinux.lds.S: catch bad .got, .plt and .rel.dyn at link time Fāng-ruì Sòng
2021-01-06 20:23 ` Nathan Chancellor
2021-01-06 20:28 ` Alexander Lobakin
2021-01-06 20:08 ` [PATCH v2 mips-next 4/4] MIPS: select ARCH_WANT_LD_ORPHAN_WARN Alexander Lobakin
2021-01-06 22:07 ` Kees Cook
2021-01-06 22:07 ` [PATCH v2 mips-next 1/4] MIPS: vmlinux.lds.S: add missing PAGE_ALIGNED_DATA() section Kees Cook
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