linux_dsm_epyc7002/drivers/misc/lkdtm/cfi.c
Kees Cook b0eb93cfd5 lkdtm: Add Control Flow Integrity test
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>
2019-08-12 15:28:51 -07:00

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");
}