The following commit has been merged into the core/build branch of tip:
Commit-ID: d1c0272bc1c068f8c2cb3d1b395173602b0df6e7
Gitweb: https://git.kernel.org/tip/d1c0272bc1c068f8c2cb3d1b395173602b0df6e7
Author: Kees Cook <keescook@xxxxxxxxxxxx>
AuthorDate: Fri, 21 Aug 2020 12:43:08 -07:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 01 Sep 2020 10:03:18 +02:00
x86/boot/compressed: Remove, discard, or assert for unwanted sections
In preparation for warning on orphan sections, stop the linker from
generating the .eh_frame* sections, discard unwanted non-zero-sized
generated sections, and enforce other expected-to-be-zero-sized sections
(since discarding them might hide problems with them suddenly gaining
unexpected entries).
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200821194310.3089815-28-keescook@xxxxxxxxxxxx
---
arch/x86/boot/compressed/Makefile | 1 +
arch/x86/boot/compressed/vmlinux.lds.S | 14 ++++++++++++--
2 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 753d572..5b7f6e1 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -50,6 +50,7 @@ GCOV_PROFILE := n
UBSAN_SANITIZE :=n
KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
+KBUILD_LDFLAGS += $(call ld-option,--no-ld-generated-unwind-info)
# Compressed kernel should be built as PIE since it may be loaded at any
# address by the bootloader.
LDFLAGS_vmlinux := -pie $(call ld-option, --no-dynamic-linker)
diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S
index ca544a1..02f6feb 100644
--- a/arch/x86/boot/compressed/vmlinux.lds.S
+++ b/arch/x86/boot/compressed/vmlinux.lds.S
@@ -72,6 +72,11 @@ SECTIONS
ELF_DETAILS
DISCARDS
+ /DISCARD/ : {
+ *(.dynamic) *(.dynsym) *(.dynstr) *(.dynbss)
+ *(.hash) *(.gnu.hash)
+ *(.note.*)
+ }
.got.plt (INFO) : {
*(.got.plt)
@@ -93,13 +98,18 @@ SECTIONS
}
ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!")
+ .plt : {
+ *(.plt) *(.plt.*)
+ }
+ ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!")
+
.rel.dyn : {
- *(.rel.*)
+ *(.rel.*) *(.rel_*)
}
ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!")
.rela.dyn : {
- *(.rela.*)
+ *(.rela.*) *(.rela_*)
}
ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!")
}
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