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Diffstat (limited to 'lib/dfsan/dfsan_custom.cpp')
| -rw-r--r-- | lib/dfsan/dfsan_custom.cpp | 1156 |
1 files changed, 1156 insertions, 0 deletions
diff --git a/lib/dfsan/dfsan_custom.cpp b/lib/dfsan/dfsan_custom.cpp new file mode 100644 index 000000000000..84f0271b15e0 --- /dev/null +++ b/lib/dfsan/dfsan_custom.cpp @@ -0,0 +1,1156 @@ +//===-- dfsan.cpp ---------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file is a part of DataFlowSanitizer. +// +// This file defines the custom functions listed in done_abilist.txt. +//===----------------------------------------------------------------------===// + +#include "sanitizer_common/sanitizer_common.h" +#include "sanitizer_common/sanitizer_internal_defs.h" +#include "sanitizer_common/sanitizer_linux.h" + +#include "dfsan/dfsan.h" + +#include <arpa/inet.h> +#include <assert.h> +#include <ctype.h> +#include <dlfcn.h> +#include <link.h> +#include <poll.h> +#include <pthread.h> +#include <pwd.h> +#include <sched.h> +#include <signal.h> +#include <stdarg.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/resource.h> +#include <sys/select.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/types.h> +#include <time.h> +#include <unistd.h> + +using namespace __dfsan; + +#define CALL_WEAK_INTERCEPTOR_HOOK(f, ...) \ + do { \ + if (f) \ + f(__VA_ARGS__); \ + } while (false) +#define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...) \ +SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void f(__VA_ARGS__); + +extern "C" { +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_stat(const char *path, struct stat *buf, dfsan_label path_label, + dfsan_label buf_label, dfsan_label *ret_label) { + int ret = stat(path, buf); + if (ret == 0) + dfsan_set_label(0, buf, sizeof(struct stat)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_fstat(int fd, struct stat *buf, + dfsan_label fd_label, + dfsan_label buf_label, + dfsan_label *ret_label) { + int ret = fstat(fd, buf); + if (ret == 0) + dfsan_set_label(0, buf, sizeof(struct stat)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c, + dfsan_label s_label, + dfsan_label c_label, + dfsan_label *ret_label) { + for (size_t i = 0;; ++i) { + if (s[i] == c || s[i] == 0) { + if (flags().strict_data_dependencies) { + *ret_label = s_label; + } else { + *ret_label = dfsan_union(dfsan_read_label(s, i + 1), + dfsan_union(s_label, c_label)); + } + return s[i] == 0 ? nullptr : const_cast<char *>(s+i); + } + } +} + +DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, uptr caller_pc, + const void *s1, const void *s2, size_t n, + dfsan_label s1_label, dfsan_label s2_label, + dfsan_label n_label) + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2, + size_t n, dfsan_label s1_label, + dfsan_label s2_label, + dfsan_label n_label, + dfsan_label *ret_label) { + CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, GET_CALLER_PC(), s1, s2, n, + s1_label, s2_label, n_label); + const char *cs1 = (const char *) s1, *cs2 = (const char *) s2; + for (size_t i = 0; i != n; ++i) { + if (cs1[i] != cs2[i]) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(cs1, i + 1), + dfsan_read_label(cs2, i + 1)); + } + return cs1[i] - cs2[i]; + } + } + + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(cs1, n), + dfsan_read_label(cs2, n)); + } + return 0; +} + +DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, uptr caller_pc, + const char *s1, const char *s2, + dfsan_label s1_label, dfsan_label s2_label) + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2, + dfsan_label s1_label, + dfsan_label s2_label, + dfsan_label *ret_label) { + CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, GET_CALLER_PC(), s1, s2, + s1_label, s2_label); + for (size_t i = 0;; ++i) { + if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), + dfsan_read_label(s2, i + 1)); + } + return s1[i] - s2[i]; + } + } + return 0; +} + +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_strcasecmp(const char *s1, const char *s2, dfsan_label s1_label, + dfsan_label s2_label, dfsan_label *ret_label) { + for (size_t i = 0;; ++i) { + if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), + dfsan_read_label(s2, i + 1)); + } + return s1[i] - s2[i]; + } + } + return 0; +} + +DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, uptr caller_pc, + const char *s1, const char *s2, size_t n, + dfsan_label s1_label, dfsan_label s2_label, + dfsan_label n_label) + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2, + size_t n, dfsan_label s1_label, + dfsan_label s2_label, + dfsan_label n_label, + dfsan_label *ret_label) { + if (n == 0) { + *ret_label = 0; + return 0; + } + + CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, GET_CALLER_PC(), s1, s2, + n, s1_label, s2_label, n_label); + + for (size_t i = 0;; ++i) { + if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || i == n - 1) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), + dfsan_read_label(s2, i + 1)); + } + return s1[i] - s2[i]; + } + } + return 0; +} + +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_strncasecmp(const char *s1, const char *s2, size_t n, + dfsan_label s1_label, dfsan_label s2_label, + dfsan_label n_label, dfsan_label *ret_label) { + if (n == 0) { + *ret_label = 0; + return 0; + } + + for (size_t i = 0;; ++i) { + if (tolower(s1[i]) != tolower(s2[i]) || s1[i] == 0 || s2[i] == 0 || + i == n - 1) { + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), + dfsan_read_label(s2, i + 1)); + } + return s1[i] - s2[i]; + } + } + return 0; +} + +SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_calloc(size_t nmemb, size_t size, + dfsan_label nmemb_label, + dfsan_label size_label, + dfsan_label *ret_label) { + void *p = calloc(nmemb, size); + dfsan_set_label(0, p, nmemb * size); + *ret_label = 0; + return p; +} + +SANITIZER_INTERFACE_ATTRIBUTE size_t +__dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) { + size_t ret = strlen(s); + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + *ret_label = dfsan_read_label(s, ret + 1); + } + return ret; +} + + +static void *dfsan_memcpy(void *dest, const void *src, size_t n) { + dfsan_label *sdest = shadow_for(dest); + const dfsan_label *ssrc = shadow_for(src); + internal_memcpy((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label)); + return internal_memcpy(dest, src, n); +} + +static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) { + internal_memset(s, c, n); + dfsan_set_label(c_label, s, n); +} + +SANITIZER_INTERFACE_ATTRIBUTE +void *__dfsw_memcpy(void *dest, const void *src, size_t n, + dfsan_label dest_label, dfsan_label src_label, + dfsan_label n_label, dfsan_label *ret_label) { + *ret_label = dest_label; + return dfsan_memcpy(dest, src, n); +} + +SANITIZER_INTERFACE_ATTRIBUTE +void *__dfsw_memset(void *s, int c, size_t n, + dfsan_label s_label, dfsan_label c_label, + dfsan_label n_label, dfsan_label *ret_label) { + dfsan_memset(s, c, c_label, n); + *ret_label = s_label; + return s; +} + +SANITIZER_INTERFACE_ATTRIBUTE char * +__dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) { + size_t len = strlen(s); + void *p = malloc(len+1); + dfsan_memcpy(p, s, len+1); + *ret_label = 0; + return static_cast<char *>(p); +} + +SANITIZER_INTERFACE_ATTRIBUTE char * +__dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label, + dfsan_label s2_label, dfsan_label n_label, + dfsan_label *ret_label) { + size_t len = strlen(s2); + if (len < n) { + dfsan_memcpy(s1, s2, len+1); + dfsan_memset(s1+len+1, 0, 0, n-len-1); + } else { + dfsan_memcpy(s1, s2, n); + } + + *ret_label = s1_label; + return s1; +} + +SANITIZER_INTERFACE_ATTRIBUTE ssize_t +__dfsw_pread(int fd, void *buf, size_t count, off_t offset, + dfsan_label fd_label, dfsan_label buf_label, + dfsan_label count_label, dfsan_label offset_label, + dfsan_label *ret_label) { + ssize_t ret = pread(fd, buf, count, offset); + if (ret > 0) + dfsan_set_label(0, buf, ret); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE ssize_t +__dfsw_read(int fd, void *buf, size_t count, + dfsan_label fd_label, dfsan_label buf_label, + dfsan_label count_label, + dfsan_label *ret_label) { + ssize_t ret = read(fd, buf, count); + if (ret > 0) + dfsan_set_label(0, buf, ret); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id, + struct timespec *tp, + dfsan_label clk_id_label, + dfsan_label tp_label, + dfsan_label *ret_label) { + int ret = clock_gettime(clk_id, tp); + if (ret == 0) + dfsan_set_label(0, tp, sizeof(struct timespec)); + *ret_label = 0; + return ret; +} + +static void unpoison(const void *ptr, uptr size) { + dfsan_set_label(0, const_cast<void *>(ptr), size); +} + +// dlopen() ultimately calls mmap() down inside the loader, which generally +// doesn't participate in dynamic symbol resolution. Therefore we won't +// intercept its calls to mmap, and we have to hook it here. +SANITIZER_INTERFACE_ATTRIBUTE void * +__dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label, + dfsan_label flag_label, dfsan_label *ret_label) { + void *handle = dlopen(filename, flag); + link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle); + if (map) + ForEachMappedRegion(map, unpoison); + *ret_label = 0; + return handle; +} + +struct pthread_create_info { + void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *); + void *start_routine; + void *arg; +}; + +static void *pthread_create_cb(void *p) { + pthread_create_info pci(*(pthread_create_info *)p); + free(p); + dfsan_label ret_label; + return pci.start_routine_trampoline(pci.start_routine, pci.arg, 0, + &ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create( + pthread_t *thread, const pthread_attr_t *attr, + void *(*start_routine_trampoline)(void *, void *, dfsan_label, + dfsan_label *), + void *start_routine, void *arg, dfsan_label thread_label, + dfsan_label attr_label, dfsan_label start_routine_label, + dfsan_label arg_label, dfsan_label *ret_label) { + pthread_create_info *pci = + (pthread_create_info *)malloc(sizeof(pthread_create_info)); + pci->start_routine_trampoline = start_routine_trampoline; + pci->start_routine = start_routine; + pci->arg = arg; + int rv = pthread_create(thread, attr, pthread_create_cb, (void *)pci); + if (rv != 0) + free(pci); + *ret_label = 0; + return rv; +} + +struct dl_iterate_phdr_info { + int (*callback_trampoline)(void *callback, struct dl_phdr_info *info, + size_t size, void *data, dfsan_label info_label, + dfsan_label size_label, dfsan_label data_label, + dfsan_label *ret_label); + void *callback; + void *data; +}; + +int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) { + dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data; + dfsan_set_label(0, *info); + dfsan_set_label(0, const_cast<char *>(info->dlpi_name), + strlen(info->dlpi_name) + 1); + dfsan_set_label( + 0, const_cast<char *>(reinterpret_cast<const char *>(info->dlpi_phdr)), + sizeof(*info->dlpi_phdr) * info->dlpi_phnum); + dfsan_label ret_label; + return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0, + 0, &ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr( + int (*callback_trampoline)(void *callback, struct dl_phdr_info *info, + size_t size, void *data, dfsan_label info_label, + dfsan_label size_label, dfsan_label data_label, + dfsan_label *ret_label), + void *callback, void *data, dfsan_label callback_label, + dfsan_label data_label, dfsan_label *ret_label) { + dl_iterate_phdr_info dipi = { callback_trampoline, callback, data }; + *ret_label = 0; + return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi); +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label, + dfsan_label buf_label, dfsan_label *ret_label) { + char *ret = ctime_r(timep, buf); + if (ret) { + dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf, + strlen(buf) + 1); + *ret_label = buf_label; + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label, + dfsan_label size_label, dfsan_label stream_label, + dfsan_label *ret_label) { + char *ret = fgets(s, size, stream); + if (ret) { + dfsan_set_label(0, ret, strlen(ret) + 1); + *ret_label = s_label; + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label, + dfsan_label size_label, dfsan_label *ret_label) { + char *ret = getcwd(buf, size); + if (ret) { + dfsan_set_label(0, ret, strlen(ret) + 1); + *ret_label = buf_label; + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_get_current_dir_name(dfsan_label *ret_label) { + char *ret = get_current_dir_name(); + if (ret) { + dfsan_set_label(0, ret, strlen(ret) + 1); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label, + dfsan_label len_label, dfsan_label *ret_label) { + int ret = gethostname(name, len); + if (ret == 0) { + dfsan_set_label(0, name, strlen(name) + 1); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_getrlimit(int resource, struct rlimit *rlim, + dfsan_label resource_label, dfsan_label rlim_label, + dfsan_label *ret_label) { + int ret = getrlimit(resource, rlim); + if (ret == 0) { + dfsan_set_label(0, rlim, sizeof(struct rlimit)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label, + dfsan_label usage_label, dfsan_label *ret_label) { + int ret = getrusage(who, usage); + if (ret == 0) { + dfsan_set_label(0, usage, sizeof(struct rusage)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label, + dfsan_label src_label, dfsan_label *ret_label) { + char *ret = strcpy(dest, src); // NOLINT + if (ret) { + internal_memcpy(shadow_for(dest), shadow_for(src), + sizeof(dfsan_label) * (strlen(src) + 1)); + } + *ret_label = dst_label; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +long int __dfsw_strtol(const char *nptr, char **endptr, int base, + dfsan_label nptr_label, dfsan_label endptr_label, + dfsan_label base_label, dfsan_label *ret_label) { + char *tmp_endptr; + long int ret = strtol(nptr, &tmp_endptr, base); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_union( + base_label, + dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +double __dfsw_strtod(const char *nptr, char **endptr, + dfsan_label nptr_label, dfsan_label endptr_label, + dfsan_label *ret_label) { + char *tmp_endptr; + double ret = strtod(nptr, &tmp_endptr); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_read_label( + nptr, + tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +long long int __dfsw_strtoll(const char *nptr, char **endptr, int base, + dfsan_label nptr_label, dfsan_label endptr_label, + dfsan_label base_label, dfsan_label *ret_label) { + char *tmp_endptr; + long long int ret = strtoll(nptr, &tmp_endptr, base); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_union( + base_label, + dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base, + dfsan_label nptr_label, dfsan_label endptr_label, + dfsan_label base_label, dfsan_label *ret_label) { + char *tmp_endptr; + unsigned long int ret = strtoul(nptr, &tmp_endptr, base); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_union( + base_label, + dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr, + dfsan_label nptr_label, + int base, dfsan_label endptr_label, + dfsan_label base_label, + dfsan_label *ret_label) { + char *tmp_endptr; + long long unsigned int ret = strtoull(nptr, &tmp_endptr, base); + if (endptr) { + *endptr = tmp_endptr; + } + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_label = dfsan_union( + base_label, + dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) { + time_t ret = time(t); + if (ret != (time_t) -1 && t) { + dfsan_set_label(0, t, sizeof(time_t)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label, + dfsan_label src_label, dfsan_label dst_label, + dfsan_label *ret_label) { + int ret = inet_pton(af, src, dst); + if (ret == 1) { + dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst, + af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result, + dfsan_label timep_label, dfsan_label result_label, + dfsan_label *ret_label) { + struct tm *ret = localtime_r(timep, result); + if (ret) { + dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result, + sizeof(struct tm)); + *ret_label = result_label; + } else { + *ret_label = 0; + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd, + char *buf, size_t buflen, struct passwd **result, + dfsan_label uid_label, dfsan_label pwd_label, + dfsan_label buf_label, dfsan_label buflen_label, + dfsan_label result_label, dfsan_label *ret_label) { + // Store the data in pwd, the strings referenced from pwd in buf, and the + // address of pwd in *result. On failure, NULL is stored in *result. + int ret = getpwuid_r(uid, pwd, buf, buflen, result); + if (ret == 0) { + dfsan_set_label(0, pwd, sizeof(struct passwd)); + dfsan_set_label(0, buf, strlen(buf) + 1); + } + *ret_label = 0; + dfsan_set_label(0, result, sizeof(struct passwd*)); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout, + dfsan_label dfs_label, dfsan_label nfds_label, + dfsan_label timeout_label, dfsan_label *ret_label) { + int ret = poll(fds, nfds, timeout); + if (ret >= 0) { + for (; nfds > 0; --nfds) { + dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents)); + } + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds, + fd_set *exceptfds, struct timeval *timeout, + dfsan_label nfds_label, dfsan_label readfds_label, + dfsan_label writefds_label, dfsan_label exceptfds_label, + dfsan_label timeout_label, dfsan_label *ret_label) { + int ret = select(nfds, readfds, writefds, exceptfds, timeout); + // Clear everything (also on error) since their content is either set or + // undefined. + if (readfds) { + dfsan_set_label(0, readfds, sizeof(fd_set)); + } + if (writefds) { + dfsan_set_label(0, writefds, sizeof(fd_set)); + } + if (exceptfds) { + dfsan_set_label(0, exceptfds, sizeof(fd_set)); + } + dfsan_set_label(0, timeout, sizeof(struct timeval)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask, + dfsan_label pid_label, + dfsan_label cpusetsize_label, + dfsan_label mask_label, dfsan_label *ret_label) { + int ret = sched_getaffinity(pid, cpusetsize, mask); + if (ret == 0) { + dfsan_set_label(0, mask, cpusetsize); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label, + dfsan_label *ret_label) { + int ret = sigemptyset(set); + dfsan_set_label(0, set, sizeof(sigset_t)); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sigaction(int signum, const struct sigaction *act, + struct sigaction *oldact, dfsan_label signum_label, + dfsan_label act_label, dfsan_label oldact_label, + dfsan_label *ret_label) { + int ret = sigaction(signum, act, oldact); + if (oldact) { + dfsan_set_label(0, oldact, sizeof(struct sigaction)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz, + dfsan_label tv_label, dfsan_label tz_label, + dfsan_label *ret_label) { + int ret = gettimeofday(tv, tz); + if (tv) { + dfsan_set_label(0, tv, sizeof(struct timeval)); + } + if (tz) { + dfsan_set_label(0, tz, sizeof(struct timezone)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n, + dfsan_label s_label, + dfsan_label c_label, + dfsan_label n_label, + dfsan_label *ret_label) { + void *ret = memchr(s, c, n); + if (flags().strict_data_dependencies) { + *ret_label = ret ? s_label : 0; + } else { + size_t len = + ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1 + : n; + *ret_label = + dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label)); + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c, + dfsan_label s_label, + dfsan_label c_label, + dfsan_label *ret_label) { + char *ret = strrchr(s, c); + if (flags().strict_data_dependencies) { + *ret_label = ret ? s_label : 0; + } else { + *ret_label = + dfsan_union(dfsan_read_label(s, strlen(s) + 1), + dfsan_union(s_label, c_label)); + } + + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle, + dfsan_label haystack_label, + dfsan_label needle_label, + dfsan_label *ret_label) { + char *ret = strstr(haystack, needle); + if (flags().strict_data_dependencies) { + *ret_label = ret ? haystack_label : 0; + } else { + size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1; + *ret_label = + dfsan_union(dfsan_read_label(haystack, len), + dfsan_union(dfsan_read_label(needle, strlen(needle) + 1), + dfsan_union(haystack_label, needle_label))); + } + + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req, + struct timespec *rem, + dfsan_label req_label, + dfsan_label rem_label, + dfsan_label *ret_label) { + int ret = nanosleep(req, rem); + *ret_label = 0; + if (ret == -1) { + // Interrupted by a signal, rem is filled with the remaining time. + dfsan_set_label(0, rem, sizeof(struct timespec)); + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_socketpair(int domain, int type, int protocol, int sv[2], + dfsan_label domain_label, dfsan_label type_label, + dfsan_label protocol_label, dfsan_label sv_label, + dfsan_label *ret_label) { + int ret = socketpair(domain, type, protocol, sv); + *ret_label = 0; + if (ret == 0) { + dfsan_set_label(0, sv, sizeof(*sv) * 2); + } + return ret; +} + +// Type of the trampoline function passed to the custom version of +// dfsan_set_write_callback. +typedef void (*write_trampoline_t)( + void *callback, + int fd, const void *buf, ssize_t count, + dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label); + +// Calls to dfsan_set_write_callback() set the values in this struct. +// Calls to the custom version of write() read (and invoke) them. +static struct { + write_trampoline_t write_callback_trampoline = nullptr; + void *write_callback = nullptr; +} write_callback_info; + +SANITIZER_INTERFACE_ATTRIBUTE void +__dfsw_dfsan_set_write_callback( + write_trampoline_t write_callback_trampoline, + void *write_callback, + dfsan_label write_callback_label, + dfsan_label *ret_label) { + write_callback_info.write_callback_trampoline = write_callback_trampoline; + write_callback_info.write_callback = write_callback; +} + +SANITIZER_INTERFACE_ATTRIBUTE int +__dfsw_write(int fd, const void *buf, size_t count, + dfsan_label fd_label, dfsan_label buf_label, + dfsan_label count_label, dfsan_label *ret_label) { + if (write_callback_info.write_callback) { + write_callback_info.write_callback_trampoline( + write_callback_info.write_callback, + fd, buf, count, + fd_label, buf_label, count_label); + } + + *ret_label = 0; + return write(fd, buf, count); +} +} // namespace __dfsan + +// Type used to extract a dfsan_label with va_arg() +typedef int dfsan_label_va; + +// Formats a chunk either a constant string or a single format directive (e.g., +// '%.3f'). +struct Formatter { + Formatter(char *str_, const char *fmt_, size_t size_) + : str(str_), str_off(0), size(size_), fmt_start(fmt_), fmt_cur(fmt_), + width(-1) {} + + int format() { + char *tmp_fmt = build_format_string(); + int retval = + snprintf(str + str_off, str_off < size ? size - str_off : 0, tmp_fmt, + 0 /* used only to avoid warnings */); + free(tmp_fmt); + return retval; + } + + template <typename T> int format(T arg) { + char *tmp_fmt = build_format_string(); + int retval; + if (width >= 0) { + retval = snprintf(str + str_off, str_off < size ? size - str_off : 0, + tmp_fmt, width, arg); + } else { + retval = snprintf(str + str_off, str_off < size ? size - str_off : 0, + tmp_fmt, arg); + } + free(tmp_fmt); + return retval; + } + + char *build_format_string() { + size_t fmt_size = fmt_cur - fmt_start + 1; + char *new_fmt = (char *)malloc(fmt_size + 1); + assert(new_fmt); + internal_memcpy(new_fmt, fmt_start, fmt_size); + new_fmt[fmt_size] = '\0'; + return new_fmt; + } + + char *str_cur() { return str + str_off; } + + size_t num_written_bytes(int retval) { + if (retval < 0) { + return 0; + } + + size_t num_avail = str_off < size ? size - str_off : 0; + if (num_avail == 0) { + return 0; + } + + size_t num_written = retval; + // A return value of {v,}snprintf of size or more means that the output was + // truncated. + if (num_written >= num_avail) { + num_written -= num_avail; + } + + return num_written; + } + + char *str; + size_t str_off; + size_t size; + const char *fmt_start; + const char *fmt_cur; + int width; +}; + +// Formats the input and propagates the input labels to the output. The output +// is stored in 'str'. 'size' bounds the number of output bytes. 'format' and +// 'ap' are the format string and the list of arguments for formatting. Returns +// the return value vsnprintf would return. +// +// The function tokenizes the format string in chunks representing either a +// constant string or a single format directive (e.g., '%.3f') and formats each +// chunk independently into the output string. This approach allows to figure +// out which bytes of the output string depends on which argument and thus to +// propagate labels more precisely. +// +// WARNING: This implementation does not support conversion specifiers with +// positional arguments. +static int format_buffer(char *str, size_t size, const char *fmt, + dfsan_label *va_labels, dfsan_label *ret_label, + va_list ap) { + Formatter formatter(str, fmt, size); + + while (*formatter.fmt_cur) { + formatter.fmt_start = formatter.fmt_cur; + formatter.width = -1; + int retval = 0; + + if (*formatter.fmt_cur != '%') { + // Ordinary character. Consume all the characters until a '%' or the end + // of the string. + for (; *(formatter.fmt_cur + 1) && *(formatter.fmt_cur + 1) != '%'; + ++formatter.fmt_cur) {} + retval = formatter.format(); + dfsan_set_label(0, formatter.str_cur(), + formatter.num_written_bytes(retval)); + } else { + // Conversion directive. Consume all the characters until a conversion + // specifier or the end of the string. + bool end_fmt = false; + for (; *formatter.fmt_cur && !end_fmt; ) { + switch (*++formatter.fmt_cur) { + case 'd': + case 'i': + case 'o': + case 'u': + case 'x': + case 'X': + switch (*(formatter.fmt_cur - 1)) { + case 'h': + // Also covers the 'hh' case (since the size of the arg is still + // an int). + retval = formatter.format(va_arg(ap, int)); + break; + case 'l': + if (formatter.fmt_cur - formatter.fmt_start >= 2 && + *(formatter.fmt_cur - 2) == 'l') { + retval = formatter.format(va_arg(ap, long long int)); + } else { + retval = formatter.format(va_arg(ap, long int)); + } + break; + case 'q': + retval = formatter.format(va_arg(ap, long long int)); + break; + case 'j': + retval = formatter.format(va_arg(ap, intmax_t)); + break; + case 'z': + case 't': + retval = formatter.format(va_arg(ap, size_t)); + break; + default: + retval = formatter.format(va_arg(ap, int)); + } + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 'a': + case 'A': + case 'e': + case 'E': + case 'f': + case 'F': + case 'g': + case 'G': + if (*(formatter.fmt_cur - 1) == 'L') { + retval = formatter.format(va_arg(ap, long double)); + } else { + retval = formatter.format(va_arg(ap, double)); + } + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 'c': + retval = formatter.format(va_arg(ap, int)); + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 's': { + char *arg = va_arg(ap, char *); + retval = formatter.format(arg); + va_labels++; + internal_memcpy(shadow_for(formatter.str_cur()), shadow_for(arg), + sizeof(dfsan_label) * + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + } + + case 'p': + retval = formatter.format(va_arg(ap, void *)); + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 'n': { + int *ptr = va_arg(ap, int *); + *ptr = (int)formatter.str_off; + va_labels++; + dfsan_set_label(0, ptr, sizeof(ptr)); + end_fmt = true; + break; + } + + case '%': + retval = formatter.format(); + dfsan_set_label(0, formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case '*': + formatter.width = va_arg(ap, int); + va_labels++; + break; + + default: + break; + } + } + } + + if (retval < 0) { + return retval; + } + + formatter.fmt_cur++; + formatter.str_off += retval; + } + + *ret_label = 0; + + // Number of bytes written in total. + return formatter.str_off; +} + +extern "C" { +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sprintf(char *str, const char *format, dfsan_label str_label, + dfsan_label format_label, dfsan_label *va_labels, + dfsan_label *ret_label, ...) { + va_list ap; + va_start(ap, ret_label); + int ret = format_buffer(str, ~0ul, format, va_labels, ret_label, ap); + va_end(ap); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_snprintf(char *str, size_t size, const char *format, + dfsan_label str_label, dfsan_label size_label, + dfsan_label format_label, dfsan_label *va_labels, + dfsan_label *ret_label, ...) { + va_list ap; + va_start(ap, ret_label); + int ret = format_buffer(str, size, format, va_labels, ret_label, ap); + va_end(ap); + return ret; +} + +// Default empty implementations (weak). Users should redefine them. +SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32 *) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init, u32 *, + u32 *) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {} + +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp1, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp2, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp4, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp8, void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp1, + void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp2, + void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp4, + void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp8, + void) {} +SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_switch, void) {} +} // extern "C" |