mirror of
https://github.com/torvalds/linux
synced 2024-10-10 05:16:04 +00:00
b0eb93cfd5
This adds a simple test for forward CFI (indirect function calls) with function prototype granularity (as implemented by Clang's CFI). Signed-off-by: Kees Cook <keescook@chromium.org>
43 lines
959 B
C
43 lines
959 B
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* This is for all the tests relating directly to Control Flow Integrity.
|
|
*/
|
|
#include "lkdtm.h"
|
|
|
|
static int called_count;
|
|
|
|
/* Function taking one argument, without a return value. */
|
|
static noinline void lkdtm_increment_void(int *counter)
|
|
{
|
|
(*counter)++;
|
|
}
|
|
|
|
/* Function taking one argument, returning int. */
|
|
static noinline int lkdtm_increment_int(int *counter)
|
|
{
|
|
(*counter)++;
|
|
|
|
return *counter;
|
|
}
|
|
/*
|
|
* This tries to call an indirect function with a mismatched prototype.
|
|
*/
|
|
void lkdtm_CFI_FORWARD_PROTO(void)
|
|
{
|
|
/*
|
|
* Matches lkdtm_increment_void()'s prototype, but not
|
|
* lkdtm_increment_int()'s prototype.
|
|
*/
|
|
void (*func)(int *);
|
|
|
|
pr_info("Calling matched prototype ...\n");
|
|
func = lkdtm_increment_void;
|
|
func(&called_count);
|
|
|
|
pr_info("Calling mismatched prototype ...\n");
|
|
func = (void *)lkdtm_increment_int;
|
|
func(&called_count);
|
|
|
|
pr_info("Fail: survived mismatched prototype function call!\n");
|
|
}
|