1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * This is for all the tests relating directly to Control Flow Integrity. 4*4882a593Smuzhiyun */ 5*4882a593Smuzhiyun #include "lkdtm.h" 6*4882a593Smuzhiyun 7*4882a593Smuzhiyun static int called_count; 8*4882a593Smuzhiyun 9*4882a593Smuzhiyun /* Function taking one argument, without a return value. */ lkdtm_increment_void(int * counter)10*4882a593Smuzhiyunstatic noinline void lkdtm_increment_void(int *counter) 11*4882a593Smuzhiyun { 12*4882a593Smuzhiyun (*counter)++; 13*4882a593Smuzhiyun } 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun /* Function taking one argument, returning int. */ lkdtm_increment_int(int * counter)16*4882a593Smuzhiyunstatic noinline int lkdtm_increment_int(int *counter) 17*4882a593Smuzhiyun { 18*4882a593Smuzhiyun (*counter)++; 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun return *counter; 21*4882a593Smuzhiyun } 22*4882a593Smuzhiyun /* 23*4882a593Smuzhiyun * This tries to call an indirect function with a mismatched prototype. 24*4882a593Smuzhiyun */ lkdtm_CFI_FORWARD_PROTO(void)25*4882a593Smuzhiyunvoid lkdtm_CFI_FORWARD_PROTO(void) 26*4882a593Smuzhiyun { 27*4882a593Smuzhiyun /* 28*4882a593Smuzhiyun * Matches lkdtm_increment_void()'s prototype, but not 29*4882a593Smuzhiyun * lkdtm_increment_int()'s prototype. 30*4882a593Smuzhiyun */ 31*4882a593Smuzhiyun void (*func)(int *); 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun pr_info("Calling matched prototype ...\n"); 34*4882a593Smuzhiyun func = lkdtm_increment_void; 35*4882a593Smuzhiyun func(&called_count); 36*4882a593Smuzhiyun 37*4882a593Smuzhiyun pr_info("Calling mismatched prototype ...\n"); 38*4882a593Smuzhiyun func = (void *)lkdtm_increment_int; 39*4882a593Smuzhiyun func(&called_count); 40*4882a593Smuzhiyun 41*4882a593Smuzhiyun pr_info("Fail: survived mismatched prototype function call!\n"); 42*4882a593Smuzhiyun } 43