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authorSami Tolvanen <samitolvanen@google.com>2022-09-09 00:54:47 +0300
committerKees Cook <keescook@chromium.org>2022-09-26 20:13:13 +0300
commit89245600941e4e0f87d77f60ee269b5e61ef4e49 (patch)
treea0069b5bd625907cb854091e6dbbeed4964815b0 /include/asm-generic/vmlinux.lds.h
parent92efda8eb15295a07f450828b2db14485bfc09c2 (diff)
downloadlinux-89245600941e4e0f87d77f60ee269b5e61ef4e49.tar.xz
cfi: Switch to -fsanitize=kcfi
Switch from Clang's original forward-edge control-flow integrity implementation to -fsanitize=kcfi, which is better suited for the kernel, as it doesn't require LTO, doesn't use a jump table that requires altering function references, and won't break cross-module function address equality. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220908215504.3686827-6-samitolvanen@google.com
Diffstat (limited to 'include/asm-generic/vmlinux.lds.h')
-rw-r--r--include/asm-generic/vmlinux.lds.h37
1 files changed, 19 insertions, 18 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 7515a465ec03..7501edfce11e 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -422,6 +422,22 @@
#endif
/*
+ * .kcfi_traps contains a list KCFI trap locations.
+ */
+#ifndef KCFI_TRAPS
+#ifdef CONFIG_ARCH_USES_CFI_TRAPS
+#define KCFI_TRAPS \
+ __kcfi_traps : AT(ADDR(__kcfi_traps) - LOAD_OFFSET) { \
+ __start___kcfi_traps = .; \
+ KEEP(*(.kcfi_traps)) \
+ __stop___kcfi_traps = .; \
+ }
+#else
+#define KCFI_TRAPS
+#endif
+#endif
+
+/*
* Read only Data
*/
#define RO_DATA(align) \
@@ -529,6 +545,8 @@
__stop___modver = .; \
} \
\
+ KCFI_TRAPS \
+ \
RO_EXCEPTION_TABLE \
NOTES \
BTF \
@@ -538,21 +556,6 @@
/*
- * .text..L.cfi.jumptable.* contain Control-Flow Integrity (CFI)
- * jump table entries.
- */
-#ifdef CONFIG_CFI_CLANG
-#define TEXT_CFI_JT \
- . = ALIGN(PMD_SIZE); \
- __cfi_jt_start = .; \
- *(.text..L.cfi.jumptable .text..L.cfi.jumptable.*) \
- . = ALIGN(PMD_SIZE); \
- __cfi_jt_end = .;
-#else
-#define TEXT_CFI_JT
-#endif
-
-/*
* Non-instrumentable text section
*/
#define NOINSTR_TEXT \
@@ -579,7 +582,6 @@
*(.text..refcount) \
*(.ref.text) \
*(.text.asan.* .text.tsan.*) \
- TEXT_CFI_JT \
MEM_KEEP(init.text*) \
MEM_KEEP(exit.text*) \
@@ -1008,8 +1010,7 @@
* keep any .init_array.* sections.
* https://bugs.llvm.org/show_bug.cgi?id=46478
*/
-#if defined(CONFIG_GCOV_KERNEL) || defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KCSAN) || \
- defined(CONFIG_CFI_CLANG)
+#if defined(CONFIG_GCOV_KERNEL) || defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KCSAN)
# ifdef CONFIG_CONSTRUCTORS
# define SANITIZER_DISCARDS \
*(.eh_frame)