void TestDEPCheckFailurePath(void) { size_t size = NACL_PAGESIZE; void *page; CHECK(NaCl_page_alloc(&page, size) == 0); CHECK(NaCl_mprotect(page, size, PROT_READ | PROT_WRITE | PROT_EXEC) == 0); CHECK(!NaClAttemptToExecuteDataAtAddr(page, size)); /* DEP is not guaranteed to work on x86-32. */ if (!(NACL_ARCH(NACL_BUILD_ARCH) == NACL_x86 && NACL_BUILD_SUBARCH == 32)) { CHECK(NaCl_mprotect(page, size, PROT_READ | PROT_WRITE) == 0); CHECK(NaClAttemptToExecuteDataAtAddr(page, size)); } NaCl_page_free(page, size); }
/* * Create thunk for use by syscall trampoline code. */ int NaClMakePcrelThunk(struct NaClApp *nap) { int retval = 0; /* fail */ int error; void *thunk_addr = NULL; struct NaClPatchInfo patch_info; uintptr_t patch_rel32[1]; /* NaClSyscallSeg */ struct NaClPatch patch_abs32[2]; /* ds, nacl_user */ /* idempotent */ nacl_pcrel_globals.user = nacl_user; nacl_pcrel_globals.sys = nacl_sys; if (0 != (error = NaCl_page_alloc(&thunk_addr, NACL_MAP_PAGESIZE))) { NaClLog(LOG_INFO, "NaClMakePcrelThunk::NaCl_page_alloc failed, errno %d\n", -error); retval = 0; goto cleanup; } patch_rel32[0] = ((uintptr_t) &NaClPcrelThunk_end) - 4; patch_abs32[0].target = ((uintptr_t) &NaClPcrelThunk_dseg_patch) - 4; patch_abs32[0].value = NaClGetGlobalDs(); patch_abs32[1].target = ((uintptr_t) &NaClPcrelThunk_globals_patch) - 4; patch_abs32[1].value = (uintptr_t) &nacl_pcrel_globals; NaClPatchInfoCtor(&patch_info); patch_info.rel32 = patch_rel32; patch_info.num_rel32 = NACL_ARRAY_SIZE(patch_rel32); patch_info.abs32 = patch_abs32; patch_info.num_abs32 = NACL_ARRAY_SIZE(patch_abs32); patch_info.dst = (uintptr_t) thunk_addr; patch_info.src = (uintptr_t) &NaClPcrelThunk; patch_info.nbytes = ((uintptr_t) &NaClPcrelThunk_end - (uintptr_t) &NaClPcrelThunk); NaClApplyPatchToMemory(&patch_info); if (0 != (error = NaCl_mprotect(thunk_addr, NACL_MAP_PAGESIZE, PROT_EXEC|PROT_READ))) { NaClLog(LOG_INFO, "NaClMakePcrelThunk::NaCl_mprotect failed, errno %d\n", -error); retval = 0; goto cleanup; } retval = 1; cleanup: if (0 == retval) { if (NULL != thunk_addr) { NaCl_page_free(thunk_addr, NACL_MAP_PAGESIZE); thunk_addr = NULL; } } else { nap->pcrel_thunk = (uintptr_t) thunk_addr; } return retval; }
int NaClMakeDispatchThunk(struct NaClApp *nap) { int retval = 0; /* fail */ int error; void *thunk_addr = NULL; struct NaClPatchInfo patch_info; struct NaClPatch jmp_target; NaClLog(LOG_WARNING, "Entered NaClMakeDispatchThunk\n"); if (0 != nap->dispatch_thunk) { NaClLog(LOG_ERROR, " dispatch_thunk already initialized!\n"); return 1; } if (0 != (error = NaCl_page_alloc_randomized(&thunk_addr, NACL_MAP_PAGESIZE))) { NaClLog(LOG_INFO, "NaClMakeDispatchThunk::NaCl_page_alloc failed, errno %d\n", -error); retval = 0; goto cleanup; } NaClLog(LOG_INFO, "NaClMakeDispatchThunk: got addr 0x%"NACL_PRIxPTR"\n", (uintptr_t) thunk_addr); if (0 != (error = NaCl_mprotect(thunk_addr, NACL_MAP_PAGESIZE, PROT_READ | PROT_WRITE))) { NaClLog(LOG_INFO, "NaClMakeDispatchThunk::NaCl_mprotect r/w failed, errno %d\n", -error); retval = 0; goto cleanup; } NaClFillMemoryRegionWithHalt(thunk_addr, NACL_MAP_PAGESIZE); jmp_target.target = (((uintptr_t) &NaClDispatchThunk_jmp_target) - sizeof(uintptr_t)); jmp_target.value = (uintptr_t) NaClSyscallSeg; NaClPatchInfoCtor(&patch_info); patch_info.abs64 = &jmp_target; patch_info.num_abs64 = 1; patch_info.dst = (uintptr_t) thunk_addr; patch_info.src = (uintptr_t) &NaClDispatchThunk; patch_info.nbytes = ((uintptr_t) &NaClDispatchThunkEnd - (uintptr_t) &NaClDispatchThunk); NaClApplyPatchToMemory(&patch_info); if (0 != (error = NaCl_mprotect(thunk_addr, NACL_MAP_PAGESIZE, PROT_EXEC|PROT_READ))) { NaClLog(LOG_INFO, "NaClMakeDispatchThunk::NaCl_mprotect r/x failed, errno %d\n", -error); retval = 0; goto cleanup; } retval = 1; cleanup: if (0 == retval) { if (NULL != thunk_addr) { NaCl_page_free(thunk_addr, NACL_MAP_PAGESIZE); thunk_addr = NULL; } } else { nap->dispatch_thunk = (uintptr_t) thunk_addr; } return retval; }