diff options
Diffstat (limited to 'executor/executor_linux.h')
| -rw-r--r-- | executor/executor_linux.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/executor/executor_linux.h b/executor/executor_linux.h index 072831816..82a1d559a 100644 --- a/executor/executor_linux.h +++ b/executor/executor_linux.h @@ -11,6 +11,8 @@ #include <sys/syscall.h> #include <unistd.h> +static bool pkeys_enabled; + const unsigned long KCOV_TRACE_PC = 0; const unsigned long KCOV_TRACE_CMP = 1; @@ -65,6 +67,22 @@ static void os_init(int argc, char** argv, char* data, size_t data_size) struct sigaction act = {}; act.sa_handler = [](int) {}; sigaction(SIGCHLD, &act, nullptr); + + // Use the last available pkey so that C reproducers get the the same keys from pkey_alloc. + int pkeys[RESERVED_PKEY + 1]; + int npkey = 0; + for (; npkey <= RESERVED_PKEY; npkey++) { + int pk = pkey_alloc(0, 0); + if (pk == -1) + break; + if (pk == RESERVED_PKEY) { + pkeys_enabled = true; + break; + } + pkeys[npkey] = pk; + } + while (npkey--) + pkey_free(pkeys[npkey]); } static intptr_t execute_syscall(const call_t* c, intptr_t a[kMaxArgs]) @@ -87,14 +105,20 @@ static void cover_open(cover_t* cov, bool extra) if (ioctl(cov->fd, kcov_init_trace, cover_size)) fail("cover init trace write failed"); cov->mmap_alloc_size = cover_size * (is_kernel_64_bit ? 8 : 4); + if (pkeys_enabled) + debug("pkey protection enabled\n"); } static void cover_protect(cover_t* cov) { + if (pkeys_enabled && pkey_set(RESERVED_PKEY, PKEY_DISABLE_WRITE)) + debug("pkey_set failed: %d\n", errno); } static void cover_unprotect(cover_t* cov) { + if (pkeys_enabled && pkey_set(RESERVED_PKEY, 0)) + debug("pkey_set failed: %d\n", errno); } static void cover_mmap(cover_t* cov) @@ -113,6 +137,8 @@ static void cover_mmap(cover_t* cov) PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, cov->fd, 0); if (cov->data == MAP_FAILED) exitf("cover mmap failed"); + if (pkeys_enabled && pkey_mprotect(cov->data, cov->mmap_alloc_size, PROT_READ | PROT_WRITE, RESERVED_PKEY)) + exitf("failed to pkey_mprotect kcov buffer"); cov->data_end = cov->data + cov->mmap_alloc_size; cov->data_offset = is_kernel_64_bit ? sizeof(uint64_t) : sizeof(uint32_t); cov->pc_offset = 0; @@ -151,7 +177,9 @@ static void cover_reset(cover_t* cov) fail("cover_reset: current_thread == 0"); cov = ¤t_thread->cov; } + cover_unprotect(cov); *(uint64*)cov->data = 0; + cover_protect(cov); } static void cover_collect(cover_t* cov) |