diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/cfi.h | 41 | ||||
| -rw-r--r-- | include/linux/compiler-clang.h | 2 | ||||
| -rw-r--r-- | include/linux/compiler_types.h | 4 | ||||
| -rw-r--r-- | include/linux/init.h | 2 | ||||
| -rw-r--r-- | include/linux/module.h | 13 |
5 files changed, 59 insertions, 3 deletions
diff --git a/include/linux/cfi.h b/include/linux/cfi.h new file mode 100644 index 000000000000..879744aaa6e0 --- /dev/null +++ b/include/linux/cfi.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Clang Control Flow Integrity (CFI) support. + * + * Copyright (C) 2021 Google LLC + */ +#ifndef _LINUX_CFI_H +#define _LINUX_CFI_H + +#ifdef CONFIG_CFI_CLANG +typedef void (*cfi_check_fn)(uint64_t id, void *ptr, void *diag); + +/* Compiler-generated function in each module, and the kernel */ +extern void __cfi_check(uint64_t id, void *ptr, void *diag); + +/* + * Force the compiler to generate a CFI jump table entry for a function + * and store the jump table address to __cfi_jt_<function>. + */ +#define __CFI_ADDRESSABLE(fn, __attr) \ + const void *__cfi_jt_ ## fn __visible __attr = (void *)&fn + +#ifdef CONFIG_CFI_CLANG_SHADOW + +extern void cfi_module_add(struct module *mod, unsigned long base_addr); +extern void cfi_module_remove(struct module *mod, unsigned long base_addr); + +#else + +static inline void cfi_module_add(struct module *mod, unsigned long base_addr) {} +static inline void cfi_module_remove(struct module *mod, unsigned long base_addr) {} + +#endif /* CONFIG_CFI_CLANG_SHADOW */ + +#else /* !CONFIG_CFI_CLANG */ + +#define __CFI_ADDRESSABLE(fn, __attr) + +#endif /* CONFIG_CFI_CLANG */ + +#endif /* _LINUX_CFI_H */ diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index d217c382b02d..6de9d0c9377e 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -61,3 +61,5 @@ #if __has_feature(shadow_call_stack) # define __noscs __attribute__((__no_sanitize__("shadow-call-stack"))) #endif + +#define __nocfi __attribute__((__no_sanitize__("cfi"))) diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index e5dd5a4ae946..796935a37e37 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -242,6 +242,10 @@ struct ftrace_likely_data { # define __noscs #endif +#ifndef __nocfi +# define __nocfi +#endif + #ifndef asm_volatile_goto #define asm_volatile_goto(x...) asm goto(x) #endif diff --git a/include/linux/init.h b/include/linux/init.h index 31f54de58429..b3ea15348fbd 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -47,7 +47,7 @@ /* These are for everybody (although not all archs will actually discard it in modules) */ -#define __init __section(".init.text") __cold __latent_entropy __noinitretpoline +#define __init __section(".init.text") __cold __latent_entropy __noinitretpoline __nocfi #define __initdata __section(".init.data") #define __initconst __section(".init.rodata") #define __exitdata __section(".exit.data") diff --git a/include/linux/module.h b/include/linux/module.h index da4b6fbe8ebe..8100bb477d86 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -26,6 +26,7 @@ #include <linux/tracepoint-defs.h> #include <linux/srcu.h> #include <linux/static_call_types.h> +#include <linux/cfi.h> #include <linux/percpu.h> #include <asm/module.h> @@ -128,13 +129,17 @@ extern void cleanup_module(void); #define module_init(initfn) \ static inline initcall_t __maybe_unused __inittest(void) \ { return initfn; } \ - int init_module(void) __copy(initfn) __attribute__((alias(#initfn))); + int init_module(void) __copy(initfn) \ + __attribute__((alias(#initfn))); \ + __CFI_ADDRESSABLE(init_module, __initdata); /* This is only required if you want to be unloadable. */ #define module_exit(exitfn) \ static inline exitcall_t __maybe_unused __exittest(void) \ { return exitfn; } \ - void cleanup_module(void) __copy(exitfn) __attribute__((alias(#exitfn))); + void cleanup_module(void) __copy(exitfn) \ + __attribute__((alias(#exitfn))); \ + __CFI_ADDRESSABLE(cleanup_module, __exitdata); #endif @@ -376,6 +381,10 @@ struct module { const s32 *crcs; unsigned int num_syms; +#ifdef CONFIG_CFI_CLANG + cfi_check_fn cfi_check; +#endif + /* Kernel parameters. */ #ifdef CONFIG_SYSFS struct mutex param_lock; |