4  * SPDX-License-Identifier: GPL-2.0-or-later
12  * Two mutator threads change the non-fixed protection bits randomly.
28 #define PAGE_IDX_MASK (PAGE_COUNT - 1)
34 #define PAGES_PER_REGION (1 << (PAGE_IDX_BITS - REGION_IDX_BITS))
50     for (i = 0; ctx->mutator_count; i++) {  in thread_read()
54         p = &ctx->ptr[j * ctx->pagesize];  in thread_read()
64         sret = write(ctx->dev_null_fd, p, 1);  in thread_read()
85     for (i = 0; ctx->mutator_count; i++) {  in thread_write()
89         memcpy(&ctx->ptr[j * ctx->pagesize], nop_func, sizeof(nop_func));  in thread_write()
92         ts = (struct timespec *)(&ctx->ptr[(j + 1) * ctx->pagesize] -  in thread_write()
109     for (i = 0; ctx->mutator_count; i++) {  in thread_execute()
111         ((void(*)(void))&ctx->ptr[j * ctx->pagesize])();  in thread_execute()
121     unsigned int seed;  in thread_mutate()  local
124     seed = (unsigned int)time(NULL);  in thread_mutate()
126         start_idx = rand_r(&seed) & PAGE_IDX_MASK;  in thread_mutate()
127         end_idx = rand_r(&seed) & PAGE_IDX_MASK;  in thread_mutate()
133         prot = rand_r(&seed) & (PROT_READ | PROT_WRITE | PROT_EXEC);  in thread_mutate()
147         ret = mprotect(&ctx->ptr[start_idx * ctx->pagesize],  in thread_mutate()
148                        (end_idx - start_idx + 1) * ctx->pagesize, prot);  in thread_mutate()
152     __atomic_fetch_sub(&ctx->mutator_count, 1, __ATOMIC_SEQ_CST);  in thread_mutate()
173                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);  in main()