usercopy: Move enum for arch_within_stack_frames()

This patch moves the arch_within_stack_frames() return value enum up in
the header files so that per-architecture implementations can reuse the
same return values.

Signed-off-by: Sahara <keun-o.park@darkmatter.ae>
Signed-off-by: James Morse <james.morse@arm.com>
[kees: adjusted naming and commit log]
Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Sahara 2017-02-16 18:29:15 +00:00 committed by Kees Cook
parent 4495c08e84
commit 96dc4f9fb6
3 changed files with 20 additions and 13 deletions

View File

@ -168,9 +168,9 @@ 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,
@ -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
}

View File

@ -22,6 +22,18 @@
#endif
#include <linux/bitops.h>
/*
* For per-arch arch_within_stack_frames() implementations, defined in
* asm/thread_info.h.
*/
enum {
BAD_STACK = -1,
NOT_STACK = 0,
GOOD_FRAME,
GOOD_STACK,
};
#include <asm/thread_info.h>
#ifdef __KERNEL__

View File

@ -19,15 +19,9 @@
#include <linux/sched.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/thread_info.h>
#include <asm/sections.h>
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).