summaryrefslogtreecommitdiff
path: root/include/linux/cfi.h
diff options
context:
space:
mode:
authorSami Tolvanen <samitolvanen@google.com>2022-09-08 14:54:47 -0700
committerKees Cook <keescook@chromium.org>2022-09-26 10:13:13 -0700
commit89245600941e4e0f87d77f60ee269b5e61ef4e49 (patch)
treea0069b5bd625907cb854091e6dbbeed4964815b0 /include/linux/cfi.h
parent92efda8eb15295a07f450828b2db14485bfc09c2 (diff)
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/linux/cfi.h')
-rw-r--r--include/linux/cfi.h29
1 files changed, 25 insertions, 4 deletions
diff --git a/include/linux/cfi.h b/include/linux/cfi.h
index 2cdbc0fbd0ab..5e134f4ce8b7 100644
--- a/include/linux/cfi.h
+++ b/include/linux/cfi.h
@@ -2,17 +2,38 @@
/*
* Clang Control Flow Integrity (CFI) support.
*
- * Copyright (C) 2021 Google LLC
+ * Copyright (C) 2022 Google LLC
*/
#ifndef _LINUX_CFI_H
#define _LINUX_CFI_H
+#include <linux/bug.h>
+#include <linux/module.h>
+
#ifdef CONFIG_CFI_CLANG
-typedef void (*cfi_check_fn)(uint64_t id, void *ptr, void *diag);
+enum bug_trap_type report_cfi_failure(struct pt_regs *regs, unsigned long addr,
+ unsigned long *target, u32 type);
-/* Compiler-generated function in each module, and the kernel */
-extern void __cfi_check(uint64_t id, void *ptr, void *diag);
+static inline enum bug_trap_type report_cfi_failure_noaddr(struct pt_regs *regs,
+ unsigned long addr)
+{
+ return report_cfi_failure(regs, addr, NULL, 0);
+}
+#ifdef CONFIG_ARCH_USES_CFI_TRAPS
+bool is_cfi_trap(unsigned long addr);
+#endif
#endif /* CONFIG_CFI_CLANG */
+#ifdef CONFIG_MODULES
+#ifdef CONFIG_ARCH_USES_CFI_TRAPS
+void module_cfi_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
+ struct module *mod);
+#else
+static inline void module_cfi_finalize(const Elf_Ehdr *hdr,
+ const Elf_Shdr *sechdrs,
+ struct module *mod) {}
+#endif /* CONFIG_ARCH_USES_CFI_TRAPS */
+#endif /* CONFIG_MODULES */
+
#endif /* _LINUX_CFI_H */