[tip: core/build] x86/boot/compressed: Reorganize zero-size section asserts

From: tip-bot2 for Kees Cook
Date: Tue Sep 01 2020 - 10:57:22 EST


The following commit has been merged into the core/build branch of tip:

Commit-ID: 7cf891a40057f851af74e68bacb01b90bd775b5d
Gitweb: https://git.kernel.org/tip/7cf891a40057f851af74e68bacb01b90bd775b5d
Author: Kees Cook <keescook@xxxxxxxxxxxx>
AuthorDate: Fri, 21 Aug 2020 12:43:07 -07:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 01 Sep 2020 10:03:18 +02:00

x86/boot/compressed: Reorganize zero-size section asserts

For readability, move the zero-sized sections to the end after DISCARDS.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200821194310.3089815-27-keescook@xxxxxxxxxxxx
---
arch/x86/boot/compressed/vmlinux.lds.S | 44 ++++++++++++++-----------
1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S
index 3c2ee9a..ca544a1 100644
--- a/arch/x86/boot/compressed/vmlinux.lds.S
+++ b/arch/x86/boot/compressed/vmlinux.lds.S
@@ -42,19 +42,6 @@ SECTIONS
*(.rodata.*)
_erodata = . ;
}
- .rel.dyn : {
- *(.rel.*)
- }
- .rela.dyn : {
- *(.rela.*)
- }
- .got : {
- *(.got)
- }
- .got.plt : {
- *(.got.plt)
- }
-
.data : {
_data = . ;
*(.data)
@@ -85,13 +72,34 @@ SECTIONS
ELF_DETAILS

DISCARDS
-}

-ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!")
+ .got.plt (INFO) : {
+ *(.got.plt)
+ }
+ ASSERT(SIZEOF(.got.plt) == 0 ||
#ifdef CONFIG_X86_64
-ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18, "Unexpected GOT/PLT entries detected!")
+ SIZEOF(.got.plt) == 0x18,
#else
-ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0xc, "Unexpected GOT/PLT entries detected!")
+ SIZEOF(.got.plt) == 0xc,
#endif
+ "Unexpected GOT/PLT entries detected!")
+
+ /*
+ * Sections that should stay zero sized, which is safer to
+ * explicitly check instead of blindly discarding.
+ */
+ .got : {
+ *(.got)
+ }
+ ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!")
+
+ .rel.dyn : {
+ *(.rel.*)
+ }
+ ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!")

-ASSERT(SIZEOF(.rel.dyn) == 0 && SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations detected!")
+ .rela.dyn : {
+ *(.rela.*)
+ }
+ ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!")
+}