From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Morse Date: Thu, 16 Feb 2017 18:29:15 +0000 Message-Id: <20170216182917.19637-2-james.morse@arm.com> In-Reply-To: <20170216182917.19637-1-james.morse@arm.com> References: <20170216182917.19637-1-james.morse@arm.com> Subject: [kernel-hardening] [PATCH v4 1/3] usercopy: create enum stack_type To: kernel-hardening@lists.openwall.com Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Catalin Marinas , keescook@chromium.org, Mark Rutland , panand@redhat.com, keun-o.park@darkmatter.ae List-ID: From: Sahara This patch creates enum stack_type which is only used in usercopy.c for now. This enum type can be used for x86 and other architecture's thread_info.h, which may have arch_within_stack_frames(). Signed-off-by: Sahara Signed-off-by: James Morse Reviewed-by: Kees Cook Acked-by: Kees Cook --- arch/x86/include/asm/thread_info.h | 19 ++++++++++--------- include/linux/thread_info.h | 13 ++++++++++--- mm/usercopy.c | 8 +------- 3 files changed, 21 insertions(+), 19 deletions(-) diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index ad6f5eb07a95..7af4b8b23b8b 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -168,13 +168,13 @@ static inline unsigned long current_stack_pointer(void) * entirely contained by a single stack frame. * * Returns: - * 1 if within a frame - * -1 if placed across a frame boundary (or outside stack) - * 0 unable to determine (no frame pointers, etc) + * GOOD_FRAME if within a frame + * BAD_STACK if placed across a frame boundary (or outside stack) + * NOT_STACK unable to determine (no frame pointers, etc) */ -static inline int arch_within_stack_frames(const void * const stack, - const void * const stackend, - const void *obj, unsigned long len) +static inline enum stack_type arch_within_stack_frames(const void * const stack, + const void * const stackend, + const void *obj, unsigned long len) { #if defined(CONFIG_FRAME_POINTER) const void *frame = NULL; @@ -197,13 +197,14 @@ static inline int arch_within_stack_frames(const void * const stack, * the copy as invalid. */ if (obj + len <= frame) - return obj >= oldframe + 2 * sizeof(void *) ? 1 : -1; + return obj >= oldframe + 2 * sizeof(void *) ? + GOOD_FRAME : BAD_STACK; oldframe = frame; frame = *(const void * const *)frame; } - return -1; + return BAD_STACK; #else - return 0; + return NOT_STACK; #endif } diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index 58373875e8ee..a38b3be347df 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -22,6 +22,13 @@ #endif #include + +enum stack_type { + BAD_STACK = -1, + NOT_STACK = 0, + GOOD_FRAME, + GOOD_STACK, +}; #include #ifdef __KERNEL__ @@ -77,9 +84,9 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag) #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES -static inline int arch_within_stack_frames(const void * const stack, - const void * const stackend, - const void *obj, unsigned long len) +static inline enum stack_type arch_within_stack_frames(const void * const stack, + const void * const stackend, + const void *obj, unsigned long len) { return 0; } diff --git a/mm/usercopy.c b/mm/usercopy.c index 3c8da0af9695..3531ae735d87 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -16,15 +16,9 @@ #include #include +#include #include -enum { - BAD_STACK = -1, - NOT_STACK = 0, - GOOD_FRAME, - GOOD_STACK, -}; - /* * Checks if a given pointer and length is contained by the current * stack frame (if possible). -- 2.10.1