diff options
| author | Kees Cook <keescook@chromium.org> | 2021-07-23 15:19:32 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2021-08-22 00:21:35 -0700 |
| commit | 1e2cd3084fff19e12bdf3c83ac1a8d64ef11aa63 (patch) | |
| tree | 87ee7c77153e420a5bebf911063c7b01cb589e4d /lib/test_stackinit.c | |
| parent | f9398f15605a50110bf570aaa361163a85113dd1 (diff) | |
lib/test_stackinit: Allow building stand-alone
Especially now that GCC is developing the -ftrivial-auto-var-init
option[1], it's helpful to have a stand-alone userspace test for stack
variable initialization. Relicense to GPLv2+ (I am the only author),
provide stand-alone kernel macro stubs, and update comments for clarity.
[1] https://gcc.gnu.org/pipermail/gcc-patches/2021-July/575198.html
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210723221933.3431999-3-keescook@chromium.org
Diffstat (limited to 'lib/test_stackinit.c')
| -rw-r--r-- | lib/test_stackinit.c | 72 |
1 files changed, 69 insertions, 3 deletions
diff --git a/lib/test_stackinit.c b/lib/test_stackinit.c index 16b1d3a3a497..70bcc1e5112c 100644 --- a/lib/test_stackinit.c +++ b/lib/test_stackinit.c @@ -1,8 +1,13 @@ -// SPDX-License-Identifier: GPL-2.0 +// SPDX-License-Identifier: GPL-2.0-or-later /* - * Test cases for compiler-based stack variable zeroing via future - * compiler flags or CONFIG_GCC_PLUGIN_STRUCTLEAK*. + * Test cases for compiler-based stack variable zeroing via + * -ftrivial-auto-var-init={zero,pattern} or CONFIG_GCC_PLUGIN_STRUCTLEAK*. + * + * External build example: + * clang -O2 -Wall -ftrivial-auto-var-init=pattern \ + * -o test_stackinit test_stackinit.c */ +#ifdef __KERNEL__ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/init.h> @@ -10,6 +15,63 @@ #include <linux/module.h> #include <linux/string.h> +#else + +/* Userspace headers. */ +#include <stdio.h> +#include <stdint.h> +#include <string.h> +#include <stdbool.h> +#include <errno.h> +#include <sys/types.h> + +/* Linux kernel-ism stubs for stand-alone userspace build. */ +#define KBUILD_MODNAME "stackinit" +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#define pr_err(fmt, ...) fprintf(stderr, pr_fmt(fmt), ##__VA_ARGS__) +#define pr_warn(fmt, ...) fprintf(stderr, pr_fmt(fmt), ##__VA_ARGS__) +#define pr_info(fmt, ...) fprintf(stdout, pr_fmt(fmt), ##__VA_ARGS__) +#define __init /**/ +#define __exit /**/ +#define __user /**/ +#define noinline __attribute__((__noinline__)) +#define __aligned(x) __attribute__((__aligned__(x))) +#ifdef __clang__ +# define __compiletime_error(message) /**/ +#else +# define __compiletime_error(message) __attribute__((__error__(message))) +#endif +#define __compiletime_assert(condition, msg, prefix, suffix) \ + do { \ + extern void prefix ## suffix(void) __compiletime_error(msg); \ + if (!(condition)) \ + prefix ## suffix(); \ + } while (0) +#define _compiletime_assert(condition, msg, prefix, suffix) \ + __compiletime_assert(condition, msg, prefix, suffix) +#define compiletime_assert(condition, msg) \ + _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) +#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) +#define BUILD_BUG_ON(condition) \ + BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) +typedef uint8_t u8; +typedef uint16_t u16; +typedef uint32_t u32; +typedef uint64_t u64; + +#define module_init(func) static int (*do_init)(void) = func +#define module_exit(func) static void (*do_exit)(void) = func +#define MODULE_LICENSE(str) int main(void) { \ + int rc; \ + /* License: str */ \ + rc = do_init(); \ + if (rc == 0) \ + do_exit(); \ + return rc; \ + } + +#endif /* __KERNEL__ */ + /* Exfiltration buffer. */ #define MAX_VAR_SIZE 128 static u8 check_buf[MAX_VAR_SIZE]; @@ -279,6 +341,10 @@ DEFINE_TEST(user, struct test_user, STRUCT, none); static int noinline __leaf_switch_none(int path, bool fill) { switch (path) { + /* + * This is intentionally unreachable. To silence the + * warning, build with -Wno-switch-unreachable + */ uint64_t var; case 1: |