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Diffstat (limited to 'contrib/llvm-project/compiler-rt/lib/dfsan/dfsan_custom.cpp')
| -rw-r--r-- | contrib/llvm-project/compiler-rt/lib/dfsan/dfsan_custom.cpp | 2905 |
1 files changed, 2905 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/dfsan/dfsan_custom.cpp b/contrib/llvm-project/compiler-rt/lib/dfsan/dfsan_custom.cpp new file mode 100644 index 000000000000..050f5232c040 --- /dev/null +++ b/contrib/llvm-project/compiler-rt/lib/dfsan/dfsan_custom.cpp @@ -0,0 +1,2905 @@ +//===-- dfsan_custom.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 <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/epoll.h> +#include <sys/resource.h> +#include <sys/select.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/types.h> +#include <time.h> +#include <unistd.h> + +#include "dfsan/dfsan.h" +#include "dfsan/dfsan_chained_origin_depot.h" +#include "dfsan/dfsan_flags.h" +#include "dfsan/dfsan_thread.h" +#include "sanitizer_common/sanitizer_common.h" +#include "sanitizer_common/sanitizer_internal_defs.h" +#include "sanitizer_common/sanitizer_linux.h" +#include "sanitizer_common/sanitizer_stackdepot.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__); + +#define WRAPPER_ALIAS(fun, real) \ + SANITIZER_INTERFACE_ATTRIBUTE void __dfsw_##fun() ALIAS(__dfsw_##real); \ + SANITIZER_INTERFACE_ATTRIBUTE void __dfso_##fun() ALIAS(__dfso_##real); + +// Async-safe, non-reentrant spin lock. +class SignalSpinLocker { + public: + SignalSpinLocker() { + sigset_t all_set; + sigfillset(&all_set); + pthread_sigmask(SIG_SETMASK, &all_set, &saved_thread_mask_); + sigactions_mu.Lock(); + } + ~SignalSpinLocker() { + sigactions_mu.Unlock(); + pthread_sigmask(SIG_SETMASK, &saved_thread_mask_, nullptr); + } + + private: + static StaticSpinMutex sigactions_mu; + sigset_t saved_thread_mask_; + + SignalSpinLocker(const SignalSpinLocker &) = delete; + SignalSpinLocker &operator=(const SignalSpinLocker &) = delete; +}; + +StaticSpinMutex SignalSpinLocker::sigactions_mu; + +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 __dfso_stat( + const char *path, struct stat *buf, dfsan_label path_label, + dfsan_label buf_label, dfsan_label *ret_label, dfsan_origin path_origin, + dfsan_origin buf_origin, dfsan_origin *ret_origin) { + int ret = __dfsw_stat(path, buf, path_label, buf_label, ret_label); + 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 int __dfso_fstat( + int fd, struct stat *buf, dfsan_label fd_label, dfsan_label buf_label, + dfsan_label *ret_label, dfsan_origin fd_origin, dfsan_origin buf_origin, + dfsan_origin *ret_origin) { + int ret = __dfsw_fstat(fd, buf, fd_label, buf_label, ret_label); + return ret; +} + +static char *dfsan_strchr_with_label(const char *s, int c, size_t *bytes_read, + dfsan_label s_label, dfsan_label c_label, + dfsan_label *ret_label) { + char *match_pos = nullptr; + for (size_t i = 0;; ++i) { + if (s[i] == c || s[i] == 0) { + // If s[i] is the \0 at the end of the string, and \0 is not the + // character we are searching for, then return null. + *bytes_read = i + 1; + match_pos = s[i] == 0 && c != 0 ? nullptr : const_cast<char *>(s + i); + break; + } + } + if (flags().strict_data_dependencies) + *ret_label = s_label; + else + *ret_label = dfsan_union(dfsan_read_label(s, *bytes_read), + dfsan_union(s_label, c_label)); + return match_pos; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c, + dfsan_label s_label, + dfsan_label c_label, + dfsan_label *ret_label) { + size_t bytes_read; + return dfsan_strchr_with_label(s, c, &bytes_read, s_label, c_label, + ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strchr( + const char *s, int c, dfsan_label s_label, dfsan_label c_label, + dfsan_label *ret_label, dfsan_origin s_origin, dfsan_origin c_origin, + dfsan_origin *ret_origin) { + size_t bytes_read; + char *r = + dfsan_strchr_with_label(s, c, &bytes_read, s_label, c_label, ret_label); + if (flags().strict_data_dependencies) { + *ret_origin = s_origin; + } else if (*ret_label) { + dfsan_origin o = dfsan_read_origin_of_first_taint(s, bytes_read); + *ret_origin = o ? o : (s_label ? s_origin : c_origin); + } + return r; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strpbrk(const char *s, + const char *accept, + dfsan_label s_label, + dfsan_label accept_label, + dfsan_label *ret_label) { + const char *ret = strpbrk(s, accept); + if (flags().strict_data_dependencies) { + *ret_label = ret ? s_label : 0; + } else { + size_t s_bytes_read = (ret ? ret - s : strlen(s)) + 1; + *ret_label = + dfsan_union(dfsan_read_label(s, s_bytes_read), + dfsan_union(dfsan_read_label(accept, strlen(accept) + 1), + dfsan_union(s_label, accept_label))); + } + return const_cast<char *>(ret); +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strpbrk( + const char *s, const char *accept, dfsan_label s_label, + dfsan_label accept_label, dfsan_label *ret_label, dfsan_origin s_origin, + dfsan_origin accept_origin, dfsan_origin *ret_origin) { + const char *ret = __dfsw_strpbrk(s, accept, s_label, accept_label, ret_label); + if (flags().strict_data_dependencies) { + if (ret) + *ret_origin = s_origin; + } else { + if (*ret_label) { + size_t s_bytes_read = (ret ? ret - s : strlen(s)) + 1; + dfsan_origin o = dfsan_read_origin_of_first_taint(s, s_bytes_read); + if (o) { + *ret_origin = o; + } else { + o = dfsan_read_origin_of_first_taint(accept, strlen(accept) + 1); + *ret_origin = o ? o : (s_label ? s_origin : accept_origin); + } + } + } + return const_cast<char *>(ret); +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strsep(char **s, const char *delim, + dfsan_label s_label, + dfsan_label delim_label, + dfsan_label *ret_label) { + dfsan_label base_label = dfsan_read_label(s, sizeof(*s)); + char *base = *s; + char *res = strsep(s, delim); + if (res != *s) { + char *token_start = res; + int token_length = strlen(res); + // the delimiter byte has been set to NULL + dfsan_set_label(0, token_start + token_length, 1); + } + + if (flags().strict_data_dependencies) { + *ret_label = res ? base_label : 0; + } else { + size_t s_bytes_read = (res ? strlen(res) : strlen(base)) + 1; + *ret_label = dfsan_union( + dfsan_union(base_label, dfsan_read_label(base, sizeof(s_bytes_read))), + dfsan_union(dfsan_read_label(delim, strlen(delim) + 1), + dfsan_union(s_label, delim_label))); + } + + return res; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strsep( + char **s, const char *delim, dfsan_label s_label, dfsan_label delim_label, + dfsan_label *ret_label, dfsan_origin s_origin, dfsan_origin delim_origin, + dfsan_origin *ret_origin) { + dfsan_origin base_origin = dfsan_read_origin_of_first_taint(s, sizeof(*s)); + char *res = __dfsw_strsep(s, delim, s_label, delim_label, ret_label); + if (flags().strict_data_dependencies) { + if (res) + *ret_origin = base_origin; + } else { + if (*ret_label) { + if (base_origin) { + *ret_origin = base_origin; + } else { + dfsan_origin o = + dfsan_read_origin_of_first_taint(delim, strlen(delim) + 1); + *ret_origin = o ? o : (s_label ? s_origin : delim_origin); + } + } + } + + return res; +} + +static int dfsan_memcmp_bcmp(const void *s1, const void *s2, size_t n, + size_t *bytes_read) { + const char *cs1 = (const char *) s1, *cs2 = (const char *) s2; + for (size_t i = 0; i != n; ++i) { + if (cs1[i] != cs2[i]) { + *bytes_read = i + 1; + return cs1[i] - cs2[i]; + } + } + *bytes_read = n; + return 0; +} + +static dfsan_label dfsan_get_memcmp_label(const void *s1, const void *s2, + size_t pos) { + if (flags().strict_data_dependencies) + return 0; + return dfsan_union(dfsan_read_label(s1, pos), dfsan_read_label(s2, pos)); +} + +static void dfsan_get_memcmp_origin(const void *s1, const void *s2, size_t pos, + dfsan_label *ret_label, + dfsan_origin *ret_origin) { + *ret_label = dfsan_get_memcmp_label(s1, s2, pos); + if (*ret_label == 0) + return; + dfsan_origin o = dfsan_read_origin_of_first_taint(s1, pos); + *ret_origin = o ? o : dfsan_read_origin_of_first_taint(s2, pos); +} + +static int dfsan_memcmp_bcmp_label(const void *s1, const void *s2, size_t n, + dfsan_label *ret_label) { + size_t bytes_read; + int r = dfsan_memcmp_bcmp(s1, s2, n, &bytes_read); + *ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read); + return r; +} + +static int dfsan_memcmp_bcmp_origin(const void *s1, const void *s2, size_t n, + dfsan_label *ret_label, + dfsan_origin *ret_origin) { + size_t bytes_read; + int r = dfsan_memcmp_bcmp(s1, s2, n, &bytes_read); + dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin); + return r; +} + +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) + +DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_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, dfsan_origin s1_origin, + dfsan_origin s2_origin, dfsan_origin n_origin) + +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); + return dfsan_memcmp_bcmp_label(s1, s2, n, ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_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, + dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin, + dfsan_origin *ret_origin) { + CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_memcmp, GET_CALLER_PC(), s1, + s2, n, s1_label, s2_label, n_label, s1_origin, + s2_origin, n_origin); + return dfsan_memcmp_bcmp_origin(s1, s2, n, ret_label, ret_origin); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_bcmp(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) { + return dfsan_memcmp_bcmp_label(s1, s2, n, ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_bcmp( + 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, + dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin, + dfsan_origin *ret_origin) { + return dfsan_memcmp_bcmp_origin(s1, s2, n, ret_label, ret_origin); +} + +// When n == 0, compare strings without byte limit. +// When n > 0, compare the first (at most) n bytes of s1 and s2. +static int dfsan_strncmp(const char *s1, const char *s2, size_t n, + size_t *bytes_read) { + for (size_t i = 0;; ++i) { + if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || (n > 0 && i == n - 1)) { + *bytes_read = i + 1; + return s1[i] - s2[i]; + } + } +} + +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) + +DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_strcmp, uptr caller_pc, + const char *s1, const char *s2, + dfsan_label s1_label, dfsan_label s2_label, + dfsan_origin s1_origin, dfsan_origin s2_origin) + +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); + size_t bytes_read; + int r = dfsan_strncmp(s1, s2, 0, &bytes_read); + *ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read); + return r; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_strcmp( + const char *s1, const char *s2, dfsan_label s1_label, dfsan_label s2_label, + dfsan_label *ret_label, dfsan_origin s1_origin, dfsan_origin s2_origin, + dfsan_origin *ret_origin) { + CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_strcmp, GET_CALLER_PC(), s1, + s2, s1_label, s2_label, s1_origin, s2_origin); + size_t bytes_read; + int r = dfsan_strncmp(s1, s2, 0, &bytes_read); + dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin); + return r; +} + +// When n == 0, compare strings without byte limit. +// When n > 0, compare the first (at most) n bytes of s1 and s2. +static int dfsan_strncasecmp(const char *s1, const char *s2, size_t n, + size_t *bytes_read) { + for (size_t i = 0;; ++i) { + char s1_lower = tolower(s1[i]); + char s2_lower = tolower(s2[i]); + + if (s1_lower != s2_lower || s1[i] == 0 || s2[i] == 0 || + (n > 0 && i == n - 1)) { + *bytes_read = i + 1; + return s1_lower - s2_lower; + } + } +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcasecmp(const char *s1, + const char *s2, + dfsan_label s1_label, + dfsan_label s2_label, + dfsan_label *ret_label) { + size_t bytes_read; + int r = dfsan_strncasecmp(s1, s2, 0, &bytes_read); + *ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read); + return r; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_strcasecmp( + const char *s1, const char *s2, dfsan_label s1_label, dfsan_label s2_label, + dfsan_label *ret_label, dfsan_origin s1_origin, dfsan_origin s2_origin, + dfsan_origin *ret_origin) { + size_t bytes_read; + int r = dfsan_strncasecmp(s1, s2, 0, &bytes_read); + dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin); + return r; +} + +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) + +DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_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, dfsan_origin s1_origin, + dfsan_origin s2_origin, dfsan_origin n_origin) + +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); + + size_t bytes_read; + int r = dfsan_strncmp(s1, s2, n, &bytes_read); + *ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read); + return r; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_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, + dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin, + dfsan_origin *ret_origin) { + if (n == 0) { + *ret_label = 0; + return 0; + } + + CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_origin_strncmp, GET_CALLER_PC(), + s1, s2, n, s1_label, s2_label, n_label, s1_origin, + s2_origin, n_origin); + + size_t bytes_read; + int r = dfsan_strncmp(s1, s2, n, &bytes_read); + dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin); + return r; +} + +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; + } + + size_t bytes_read; + int r = dfsan_strncasecmp(s1, s2, n, &bytes_read); + *ret_label = dfsan_get_memcmp_label(s1, s2, bytes_read); + return r; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_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, + dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin, + dfsan_origin *ret_origin) { + if (n == 0) { + *ret_label = 0; + return 0; + } + + size_t bytes_read; + int r = dfsan_strncasecmp(s1, s2, n, &bytes_read); + dfsan_get_memcmp_origin(s1, s2, bytes_read, ret_label, ret_origin); + return r; +} + + +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; +} + +SANITIZER_INTERFACE_ATTRIBUTE size_t __dfso_strlen(const char *s, + dfsan_label s_label, + dfsan_label *ret_label, + dfsan_origin s_origin, + dfsan_origin *ret_origin) { + size_t ret = __dfsw_strlen(s, s_label, ret_label); + if (!flags().strict_data_dependencies) + *ret_origin = dfsan_read_origin_of_first_taint(s, ret + 1); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE size_t __dfsw_strnlen(const char *s, + size_t maxlen, + dfsan_label s_label, + dfsan_label maxlen_label, + dfsan_label *ret_label) { + size_t ret = strnlen(s, maxlen); + if (flags().strict_data_dependencies) { + *ret_label = 0; + } else { + size_t full_len = strlen(s); + size_t covered_len = maxlen > (full_len + 1) ? (full_len + 1) : maxlen; + *ret_label = dfsan_union(maxlen_label, dfsan_read_label(s, covered_len)); + } + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE size_t __dfso_strnlen( + const char *s, size_t maxlen, dfsan_label s_label, dfsan_label maxlen_label, + dfsan_label *ret_label, dfsan_origin s_origin, dfsan_origin maxlen_origin, + dfsan_origin *ret_origin) { + size_t ret = __dfsw_strnlen(s, maxlen, s_label, maxlen_label, ret_label); + if (!flags().strict_data_dependencies) { + size_t full_len = strlen(s); + size_t covered_len = maxlen > (full_len + 1) ? (full_len + 1) : maxlen; + dfsan_origin o = dfsan_read_origin_of_first_taint(s, covered_len); + *ret_origin = o ? o : maxlen_origin; + } + return ret; +} + +static void *dfsan_memmove(void *dest, const void *src, size_t n) { + dfsan_label *sdest = shadow_for(dest); + const dfsan_label *ssrc = shadow_for(src); + internal_memmove((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label)); + return internal_memmove(dest, src, n); +} + +static void *dfsan_memmove_with_origin(void *dest, const void *src, size_t n) { + dfsan_mem_origin_transfer(dest, src, n); + return dfsan_memmove(dest, src, n); +} + +static void *dfsan_memcpy(void *dest, const void *src, size_t n) { + dfsan_mem_shadow_transfer(dest, src, n); + return internal_memcpy(dest, src, n); +} + +static void *dfsan_memcpy_with_origin(void *dest, const void *src, size_t n) { + dfsan_mem_origin_transfer(dest, src, n); + return dfsan_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); +} + +static void dfsan_memset_with_origin(void *s, int c, dfsan_label c_label, + dfsan_origin c_origin, size_t n) { + internal_memset(s, c, n); + dfsan_set_label_origin(c_label, c_origin, 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 *__dfso_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, + dfsan_origin dest_origin, dfsan_origin src_origin, + dfsan_origin n_origin, dfsan_origin *ret_origin) { + *ret_label = dest_label; + *ret_origin = dest_origin; + return dfsan_memcpy_with_origin(dest, src, n); +} + +SANITIZER_INTERFACE_ATTRIBUTE +void *__dfsw_memmove(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_memmove(dest, src, n); +} + +SANITIZER_INTERFACE_ATTRIBUTE +void *__dfso_memmove(void *dest, const void *src, size_t n, + dfsan_label dest_label, dfsan_label src_label, + dfsan_label n_label, dfsan_label *ret_label, + dfsan_origin dest_origin, dfsan_origin src_origin, + dfsan_origin n_origin, dfsan_origin *ret_origin) { + *ret_label = dest_label; + *ret_origin = dest_origin; + return dfsan_memmove_with_origin(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 +void *__dfso_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_origin s_origin, + dfsan_origin c_origin, dfsan_origin n_origin, + dfsan_origin *ret_origin) { + dfsan_memset_with_origin(s, c, c_label, c_origin, n); + *ret_label = s_label; + *ret_origin = s_origin; + return s; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strcat(char *dest, const char *src, + dfsan_label dest_label, + dfsan_label src_label, + dfsan_label *ret_label) { + size_t dest_len = strlen(dest); + char *ret = strcat(dest, src); + dfsan_mem_shadow_transfer(dest + dest_len, src, strlen(src)); + *ret_label = dest_label; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strcat( + char *dest, const char *src, dfsan_label dest_label, dfsan_label src_label, + dfsan_label *ret_label, dfsan_origin dest_origin, dfsan_origin src_origin, + dfsan_origin *ret_origin) { + size_t dest_len = strlen(dest); + char *ret = strcat(dest, src); + size_t src_len = strlen(src); + dfsan_mem_origin_transfer(dest + dest_len, src, src_len); + dfsan_mem_shadow_transfer(dest + dest_len, src, src_len); + *ret_label = dest_label; + *ret_origin = dest_origin; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strncat( + char *dest, const char *src, size_t num, dfsan_label dest_label, + dfsan_label src_label, dfsan_label num_label, dfsan_label *ret_label) { + size_t src_len = strlen(src); + src_len = src_len < num ? src_len : num; + size_t dest_len = strlen(dest); + + char *ret = strncat(dest, src, num); + dfsan_mem_shadow_transfer(dest + dest_len, src, src_len); + *ret_label = dest_label; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE char *__dfso_strncat( + char *dest, const char *src, size_t num, dfsan_label dest_label, + dfsan_label src_label, dfsan_label num_label, dfsan_label *ret_label, + dfsan_origin dest_origin, dfsan_origin src_origin, dfsan_origin num_origin, + dfsan_origin *ret_origin) { + size_t src_len = strlen(src); + src_len = src_len < num ? src_len : num; + size_t dest_len = strlen(dest); + + char *ret = strncat(dest, src, num); + + dfsan_mem_origin_transfer(dest + dest_len, src, src_len); + dfsan_mem_shadow_transfer(dest + dest_len, src, src_len); + *ret_label = dest_label; + *ret_origin = dest_origin; + return ret; +} + +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 *__dfso_strdup(const char *s, + dfsan_label s_label, + dfsan_label *ret_label, + dfsan_origin s_origin, + dfsan_origin *ret_origin) { + size_t len = strlen(s); + void *p = malloc(len + 1); + dfsan_memcpy_with_origin(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 char *__dfso_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, + dfsan_origin s1_origin, dfsan_origin s2_origin, dfsan_origin n_origin, + dfsan_origin *ret_origin) { + size_t len = strlen(s2); + if (len < n) { + dfsan_memcpy_with_origin(s1, s2, len + 1); + dfsan_memset_with_origin(s1 + len + 1, 0, 0, 0, n - len - 1); + } else { + dfsan_memcpy_with_origin(s1, s2, n); + } + + *ret_label = s1_label; + *ret_origin = s1_origin; + 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 __dfso_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, dfsan_origin fd_origin, dfsan_origin buf_origin, + dfsan_origin count_origin, dfsan_label offset_origin, + dfsan_origin *ret_origin) { + return __dfsw_pread(fd, buf, count, offset, fd_label, buf_label, count_label, + offset_label, ret_label); +} + +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 ssize_t __dfso_read( + int fd, void *buf, size_t count, dfsan_label fd_label, + dfsan_label buf_label, dfsan_label count_label, dfsan_label *ret_label, + dfsan_origin fd_origin, dfsan_origin buf_origin, dfsan_origin count_origin, + dfsan_origin *ret_origin) { + return __dfsw_read(fd, buf, count, fd_label, buf_label, count_label, + ret_label); +} + +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; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_clock_gettime( + clockid_t clk_id, struct timespec *tp, dfsan_label clk_id_label, + dfsan_label tp_label, dfsan_label *ret_label, dfsan_origin clk_id_origin, + dfsan_origin tp_origin, dfsan_origin *ret_origin) { + return __dfsw_clock_gettime(clk_id, tp, clk_id_label, tp_label, ret_label); +} + +static void dfsan_set_zero_label(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 (filename && map) + ForEachMappedRegion(map, dfsan_set_zero_label); + *ret_label = 0; + return handle; +} + +SANITIZER_INTERFACE_ATTRIBUTE void *__dfso_dlopen( + const char *filename, int flag, dfsan_label filename_label, + dfsan_label flag_label, dfsan_label *ret_label, + dfsan_origin filename_origin, dfsan_origin flag_origin, + dfsan_origin *ret_origin) { + return __dfsw_dlopen(filename, flag, filename_label, flag_label, ret_label); +} + +static void *DFsanThreadStartFunc(void *arg) { + DFsanThread *t = (DFsanThread *)arg; + SetCurrentThread(t); + t->Init(); + SetSigProcMask(&t->starting_sigset_, nullptr); + return t->ThreadStart(); +} + +static int dfsan_pthread_create(pthread_t *thread, const pthread_attr_t *attr, + void *start_routine, void *arg, + dfsan_label *ret_label, + bool track_origins = false) { + pthread_attr_t myattr; + if (!attr) { + pthread_attr_init(&myattr); + attr = &myattr; + } + + // Ensure that the thread stack is large enough to hold all TLS data. + AdjustStackSize((void *)(const_cast<pthread_attr_t *>(attr))); + + DFsanThread *t = + DFsanThread::Create((thread_callback_t)start_routine, arg, track_origins); + ScopedBlockSignals block(&t->starting_sigset_); + int res = pthread_create(thread, attr, DFsanThreadStartFunc, t); + + if (attr == &myattr) + pthread_attr_destroy(&myattr); + *ret_label = 0; + return res; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create( + pthread_t *thread, const pthread_attr_t *attr, 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) { + return dfsan_pthread_create(thread, attr, start_routine, arg, ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_pthread_create( + pthread_t *thread, const pthread_attr_t *attr, 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, dfsan_origin thread_origin, + dfsan_origin attr_origin, dfsan_origin start_routine_origin, + dfsan_origin arg_origin, dfsan_origin *ret_origin) { + return dfsan_pthread_create(thread, attr, start_routine, arg, ret_label, + true); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_join(pthread_t thread, + void **retval, + dfsan_label thread_label, + dfsan_label retval_label, + dfsan_label *ret_label) { + int ret = pthread_join(thread, retval); + if (ret == 0 && retval) + dfsan_set_label(0, retval, sizeof(*retval)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_pthread_join( + pthread_t thread, void **retval, dfsan_label thread_label, + dfsan_label retval_label, dfsan_label *ret_label, + dfsan_origin thread_origin, dfsan_origin retval_origin, + dfsan_origin *ret_origin) { + return __dfsw_pthread_join(thread, retval, thread_label, retval_label, + ret_label); +} + +struct dl_iterate_phdr_info { + int (*callback)(struct dl_phdr_info *info, size_t size, void *data); + 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_clear_thread_local_state(); + return dipi->callback(info, size, dipi->data); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr( + int (*callback)(struct dl_phdr_info *info, size_t size, void *data), + void *data, dfsan_label callback_label, dfsan_label data_label, + dfsan_label *ret_label) { + dl_iterate_phdr_info dipi = {callback, data}; + *ret_label = 0; + return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_dl_iterate_phdr( + int (*callback)(struct dl_phdr_info *info, size_t size, void *data), + void *data, dfsan_label callback_label, dfsan_label data_label, + dfsan_label *ret_label, dfsan_origin callback_origin, + dfsan_origin data_origin, dfsan_origin *ret_origin) { + dl_iterate_phdr_info dipi = {callback, data}; + *ret_label = 0; + return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi); +} + +// This function is only available for glibc 2.27 or newer. Mark it weak so +// linking succeeds with older glibcs. +SANITIZER_WEAK_ATTRIBUTE void _dl_get_tls_static_info(size_t *sizep, + size_t *alignp); + +SANITIZER_INTERFACE_ATTRIBUTE void __dfsw__dl_get_tls_static_info( + size_t *sizep, size_t *alignp, dfsan_label sizep_label, + dfsan_label alignp_label) { + assert(_dl_get_tls_static_info); + _dl_get_tls_static_info(sizep, alignp); + dfsan_set_label(0, sizep, sizeof(*sizep)); + dfsan_set_label(0, alignp, sizeof(*alignp)); +} + +SANITIZER_INTERFACE_ATTRIBUTE void __dfso__dl_get_tls_static_info( + size_t *sizep, size_t *alignp, dfsan_label sizep_label, + dfsan_label alignp_label, dfsan_origin sizep_origin, + dfsan_origin alignp_origin) { + __dfsw__dl_get_tls_static_info(sizep, alignp, sizep_label, alignp_label); +} + +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 *__dfso_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label, + dfsan_label buf_label, dfsan_label *ret_label, + dfsan_origin timep_origin, dfsan_origin buf_origin, + dfsan_origin *ret_origin) { + char *ret = ctime_r(timep, buf); + if (ret) { + dfsan_set_label_origin( + dfsan_read_label(timep, sizeof(time_t)), + dfsan_read_origin_of_first_taint(timep, sizeof(time_t)), buf, + strlen(buf) + 1); + *ret_label = buf_label; + *ret_origin = buf_origin; + } 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 *__dfso_fgets(char *s, int size, FILE *stream, dfsan_label s_label, + dfsan_label size_label, dfsan_label stream_label, + dfsan_label *ret_label, dfsan_origin s_origin, + dfsan_origin size_origin, dfsan_origin stream_origin, + dfsan_origin *ret_origin) { + char *ret = __dfsw_fgets(s, size, stream, s_label, size_label, stream_label, + ret_label); + if (ret) + *ret_origin = s_origin; + 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 *__dfso_getcwd(char *buf, size_t size, dfsan_label buf_label, + dfsan_label size_label, dfsan_label *ret_label, + dfsan_origin buf_origin, dfsan_origin size_origin, + dfsan_origin *ret_origin) { + char *ret = __dfsw_getcwd(buf, size, buf_label, size_label, ret_label); + if (ret) + *ret_origin = buf_origin; + 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 +char *__dfso_get_current_dir_name(dfsan_label *ret_label, + dfsan_origin *ret_origin) { + return __dfsw_get_current_dir_name(ret_label); +} + +// This function is only available for glibc 2.25 or newer. Mark it weak so +// linking succeeds with older glibcs. +SANITIZER_WEAK_ATTRIBUTE int getentropy(void *buffer, size_t length); + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getentropy(void *buffer, size_t length, + dfsan_label buffer_label, + dfsan_label length_label, + dfsan_label *ret_label) { + int ret = getentropy(buffer, length); + if (ret == 0) { + dfsan_set_label(0, buffer, length); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_getentropy(void *buffer, size_t length, + dfsan_label buffer_label, + dfsan_label length_label, + dfsan_label *ret_label, + dfsan_origin buffer_origin, + dfsan_origin length_origin, + dfsan_origin *ret_origin) { + return __dfsw_getentropy(buffer, length, buffer_label, length_label, + ret_label); +} + +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 __dfso_gethostname(char *name, size_t len, dfsan_label name_label, + dfsan_label len_label, dfsan_label *ret_label, + dfsan_origin name_origin, dfsan_origin len_origin, + dfsan_label *ret_origin) { + return __dfsw_gethostname(name, len, name_label, len_label, ret_label); +} + +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 __dfso_getrlimit(int resource, struct rlimit *rlim, + dfsan_label resource_label, dfsan_label rlim_label, + dfsan_label *ret_label, dfsan_origin resource_origin, + dfsan_origin rlim_origin, dfsan_origin *ret_origin) { + return __dfsw_getrlimit(resource, rlim, resource_label, rlim_label, + ret_label); +} + +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 +int __dfso_getrusage(int who, struct rusage *usage, dfsan_label who_label, + dfsan_label usage_label, dfsan_label *ret_label, + dfsan_origin who_origin, dfsan_origin usage_origin, + dfsan_label *ret_origin) { + return __dfsw_getrusage(who, usage, who_label, usage_label, ret_label); +} + +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); + if (ret) { + dfsan_mem_shadow_transfer(dest, src, strlen(src) + 1); + } + *ret_label = dst_label; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +char *__dfso_strcpy(char *dest, const char *src, dfsan_label dst_label, + dfsan_label src_label, dfsan_label *ret_label, + dfsan_origin dst_origin, dfsan_origin src_origin, + dfsan_origin *ret_origin) { + char *ret = strcpy(dest, src); + if (ret) { + size_t str_len = strlen(src) + 1; + dfsan_mem_origin_transfer(dest, src, str_len); + dfsan_mem_shadow_transfer(dest, src, str_len); + } + *ret_label = dst_label; + *ret_origin = dst_origin; + return ret; +} +} + +template <typename Fn> +static ALWAYS_INLINE auto dfsan_strtol_impl( + Fn real, const char *nptr, char **endptr, int base, + char **tmp_endptr) -> decltype(real(nullptr, nullptr, 0)) { + assert(tmp_endptr); + auto ret = real(nptr, tmp_endptr, base); + if (endptr) + *endptr = *tmp_endptr; + return ret; +} + +extern "C" { +static void dfsan_strtolong_label(const char *nptr, const char *tmp_endptr, + dfsan_label base_label, + dfsan_label *ret_label) { + 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; + } +} + +static void dfsan_strtolong_origin(const char *nptr, const char *tmp_endptr, + dfsan_label base_label, + dfsan_label *ret_label, + dfsan_origin base_origin, + dfsan_origin *ret_origin) { + if (tmp_endptr > nptr) { + // When multiple inputs are tainted, we propagate one of its origins. + // Because checking if base_label is tainted does not need additional + // computation, we prefer to propagating base_origin. + *ret_origin = base_label + ? base_origin + : dfsan_read_origin_of_first_taint( + nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)); + } +} + +static double dfsan_strtod(const char *nptr, char **endptr, char **tmp_endptr) { + assert(tmp_endptr); + double ret = strtod(nptr, tmp_endptr); + if (endptr) + *endptr = *tmp_endptr; + return ret; +} + +static void dfsan_strtod_label(const char *nptr, const char *tmp_endptr, + dfsan_label *ret_label) { + 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; + } +} + +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 = dfsan_strtod(nptr, endptr, &tmp_endptr); + dfsan_strtod_label(nptr, tmp_endptr, ret_label); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +double __dfso_strtod(const char *nptr, char **endptr, dfsan_label nptr_label, + dfsan_label endptr_label, dfsan_label *ret_label, + dfsan_origin nptr_origin, dfsan_origin endptr_origin, + dfsan_origin *ret_origin) { + char *tmp_endptr; + double ret = dfsan_strtod(nptr, endptr, &tmp_endptr); + dfsan_strtod_label(nptr, tmp_endptr, ret_label); + if (tmp_endptr > nptr) { + // If *tmp_endptr is '\0' include its label as well. + *ret_origin = dfsan_read_origin_of_first_taint( + nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)); + } else { + *ret_origin = 0; + } + return ret; +} + +WRAPPER_ALIAS(__isoc23_strtod, strtod) + +#define WRAPPER_STRTO(ret_type, fun) \ + SANITIZER_INTERFACE_ATTRIBUTE ret_type __dfsw_##fun( \ + 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; \ + auto ret = dfsan_strtol_impl(fun, nptr, endptr, base, &tmp_endptr); \ + dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label); \ + return ret; \ + } \ + SANITIZER_INTERFACE_ATTRIBUTE ret_type __dfso_##fun( \ + const char *nptr, char **endptr, int base, dfsan_label nptr_label, \ + dfsan_label endptr_label, dfsan_label base_label, \ + dfsan_label *ret_label, dfsan_origin nptr_origin, \ + dfsan_origin endptr_origin, dfsan_origin base_origin, \ + dfsan_origin *ret_origin) { \ + char *tmp_endptr; \ + auto ret = dfsan_strtol_impl(fun, nptr, endptr, base, &tmp_endptr); \ + dfsan_strtolong_label(nptr, tmp_endptr, base_label, ret_label); \ + dfsan_strtolong_origin(nptr, tmp_endptr, base_label, ret_label, \ + base_origin, ret_origin); \ + return ret; \ + } + +WRAPPER_STRTO(long, strtol) +WRAPPER_STRTO(long long, strtoll) +WRAPPER_STRTO(unsigned long, strtoul) +WRAPPER_STRTO(unsigned long long, strtoull) +WRAPPER_ALIAS(__isoc23_strtol, strtol) +WRAPPER_ALIAS(__isoc23_strtoll, strtoll) +WRAPPER_ALIAS(__isoc23_strtoul, strtoul) +WRAPPER_ALIAS(__isoc23_strtoull, strtoull) + +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 +time_t __dfso_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label, + dfsan_origin t_origin, dfsan_origin *ret_origin) { + return __dfsw_time(t, t_label, ret_label); +} + +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 +int __dfso_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, dfsan_origin af_origin, + dfsan_origin src_origin, dfsan_origin dst_origin, + dfsan_origin *ret_origin) { + int ret = inet_pton(af, src, dst); + if (ret == 1) { + int src_len = strlen(src) + 1; + dfsan_set_label_origin( + dfsan_read_label(src, src_len), + dfsan_read_origin_of_first_taint(src, src_len), 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 +struct tm *__dfso_localtime_r(const time_t *timep, struct tm *result, + dfsan_label timep_label, dfsan_label result_label, + dfsan_label *ret_label, dfsan_origin timep_origin, + dfsan_origin result_origin, + dfsan_origin *ret_origin) { + struct tm *ret = localtime_r(timep, result); + if (ret) { + dfsan_set_label_origin( + dfsan_read_label(timep, sizeof(time_t)), + dfsan_read_origin_of_first_taint(timep, sizeof(time_t)), result, + sizeof(struct tm)); + *ret_label = result_label; + *ret_origin = result_origin; + } 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 __dfso_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, dfsan_origin uid_origin, + dfsan_origin pwd_origin, dfsan_origin buf_origin, + dfsan_origin buflen_origin, dfsan_origin result_origin, + dfsan_origin *ret_origin) { + return __dfsw_getpwuid_r(uid, pwd, buf, buflen, result, uid_label, pwd_label, + buf_label, buflen_label, result_label, ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_epoll_wait(int epfd, struct epoll_event *events, int maxevents, + int timeout, dfsan_label epfd_label, + dfsan_label events_label, dfsan_label maxevents_label, + dfsan_label timeout_label, dfsan_label *ret_label) { + int ret = epoll_wait(epfd, events, maxevents, timeout); + if (ret > 0) + dfsan_set_label(0, events, ret * sizeof(*events)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfso_epoll_wait(int epfd, struct epoll_event *events, int maxevents, + int timeout, dfsan_label epfd_label, + dfsan_label events_label, dfsan_label maxevents_label, + dfsan_label timeout_label, dfsan_label *ret_label, + dfsan_origin epfd_origin, dfsan_origin events_origin, + dfsan_origin maxevents_origin, + dfsan_origin timeout_origin, dfsan_origin *ret_origin) { + return __dfsw_epoll_wait(epfd, events, maxevents, timeout, epfd_label, + events_label, maxevents_label, timeout_label, + ret_label); +} + +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 __dfso_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, + dfsan_origin dfs_origin, dfsan_origin nfds_origin, + dfsan_origin timeout_origin, dfsan_origin *ret_origin) { + return __dfsw_poll(fds, nfds, timeout, dfs_label, nfds_label, timeout_label, + ret_label); +} + +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 __dfso_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, + dfsan_origin nfds_origin, dfsan_origin readfds_origin, + dfsan_origin writefds_origin, dfsan_origin exceptfds_origin, + dfsan_origin timeout_origin, dfsan_origin *ret_origin) { + return __dfsw_select(nfds, readfds, writefds, exceptfds, timeout, nfds_label, + readfds_label, writefds_label, exceptfds_label, + timeout_label, ret_label); +} + +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 __dfso_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, + dfsan_origin pid_origin, + dfsan_origin cpusetsize_origin, + dfsan_origin mask_origin, + dfsan_origin *ret_origin) { + return __dfsw_sched_getaffinity(pid, cpusetsize, mask, pid_label, + cpusetsize_label, mask_label, ret_label); +} + +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)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfso_sigemptyset(sigset_t *set, dfsan_label set_label, + dfsan_label *ret_label, dfsan_origin set_origin, + dfsan_origin *ret_origin) { + return __dfsw_sigemptyset(set, set_label, ret_label); +} + +class SignalHandlerScope { + public: + SignalHandlerScope() { + if (DFsanThread *t = GetCurrentThread()) + t->EnterSignalHandler(); + } + ~SignalHandlerScope() { + if (DFsanThread *t = GetCurrentThread()) + t->LeaveSignalHandler(); + } +}; + +// Clear DFSan runtime TLS state at the end of a scope. +// +// Implementation must be async-signal-safe and use small data size, because +// instances of this class may live on the signal handler stack. +// +// DFSan uses TLS to pass metadata of arguments and return values. When an +// instrumented function accesses the TLS, if a signal callback happens, and the +// callback calls other instrumented functions with updating the same TLS, the +// TLS is in an inconsistent state after the callback ends. This may cause +// either under-tainting or over-tainting. +// +// The current implementation simply resets TLS at restore. This prevents from +// over-tainting. Although under-tainting may still happen, a taint flow can be +// found eventually if we run a DFSan-instrumented program multiple times. The +// alternative option is saving the entire TLS. However the TLS storage takes +// 2k bytes, and signal calls could be nested. So it does not seem worth. +class ScopedClearThreadLocalState { + public: + ScopedClearThreadLocalState() {} + ~ScopedClearThreadLocalState() { dfsan_clear_thread_local_state(); } +}; + +// SignalSpinLocker::sigactions_mu guarantees atomicity of sigaction() calls. +const int kMaxSignals = 1024; +static atomic_uintptr_t sigactions[kMaxSignals]; + +static void SignalHandler(int signo) { + SignalHandlerScope signal_handler_scope; + ScopedClearThreadLocalState scoped_clear_tls; + + // Clear shadows for all inputs provided by system. + dfsan_clear_arg_tls(0, sizeof(dfsan_label)); + + typedef void (*signal_cb)(int x); + signal_cb cb = + (signal_cb)atomic_load(&sigactions[signo], memory_order_relaxed); + cb(signo); +} + +static void SignalAction(int signo, siginfo_t *si, void *uc) { + SignalHandlerScope signal_handler_scope; + ScopedClearThreadLocalState scoped_clear_tls; + + // Clear shadows for all inputs provided by system. Similar to SignalHandler. + dfsan_clear_arg_tls(0, 3 * sizeof(dfsan_label)); + dfsan_set_label(0, si, sizeof(*si)); + dfsan_set_label(0, uc, sizeof(ucontext_t)); + + typedef void (*sigaction_cb)(int, siginfo_t *, void *); + sigaction_cb cb = + (sigaction_cb)atomic_load(&sigactions[signo], memory_order_relaxed); + cb(signo, si, uc); +} + +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) { + CHECK_LT(signum, kMaxSignals); + SignalSpinLocker lock; + uptr old_cb = atomic_load(&sigactions[signum], memory_order_relaxed); + struct sigaction new_act; + struct sigaction *pnew_act = act ? &new_act : nullptr; + if (act) { + internal_memcpy(pnew_act, act, sizeof(struct sigaction)); + if (pnew_act->sa_flags & SA_SIGINFO) { + uptr cb = (uptr)(pnew_act->sa_sigaction); + if (cb != (uptr)SIG_IGN && cb != (uptr)SIG_DFL) { + atomic_store(&sigactions[signum], cb, memory_order_relaxed); + pnew_act->sa_sigaction = SignalAction; + } + } else { + uptr cb = (uptr)(pnew_act->sa_handler); + if (cb != (uptr)SIG_IGN && cb != (uptr)SIG_DFL) { + atomic_store(&sigactions[signum], cb, memory_order_relaxed); + pnew_act->sa_handler = SignalHandler; + } + } + } + + int ret = sigaction(signum, pnew_act, oldact); + + if (ret == 0 && oldact) { + if (oldact->sa_flags & SA_SIGINFO) { + if (oldact->sa_sigaction == SignalAction) + oldact->sa_sigaction = (decltype(oldact->sa_sigaction))old_cb; + } else { + if (oldact->sa_handler == SignalHandler) + oldact->sa_handler = (decltype(oldact->sa_handler))old_cb; + } + } + + if (oldact) { + dfsan_set_label(0, oldact, sizeof(struct sigaction)); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfso_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, dfsan_origin signum_origin, + dfsan_origin act_origin, dfsan_origin oldact_origin, + dfsan_origin *ret_origin) { + return __dfsw_sigaction(signum, act, oldact, signum_label, act_label, + oldact_label, ret_label); +} + +static sighandler_t dfsan_signal(int signum, sighandler_t handler, + dfsan_label *ret_label) { + CHECK_LT(signum, kMaxSignals); + SignalSpinLocker lock; + uptr old_cb = atomic_load(&sigactions[signum], memory_order_relaxed); + if (handler != SIG_IGN && handler != SIG_DFL) { + atomic_store(&sigactions[signum], (uptr)handler, memory_order_relaxed); + handler = &SignalHandler; + } + + sighandler_t ret = signal(signum, handler); + + if (ret == SignalHandler) + ret = (sighandler_t)old_cb; + + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +sighandler_t __dfsw_signal(int signum, sighandler_t handler, + dfsan_label signum_label, dfsan_label handler_label, + dfsan_label *ret_label) { + return dfsan_signal(signum, handler, ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE +sighandler_t __dfso_signal(int signum, sighandler_t handler, + dfsan_label signum_label, dfsan_label handler_label, + dfsan_label *ret_label, dfsan_origin signum_origin, + dfsan_origin handler_origin, + dfsan_origin *ret_origin) { + return dfsan_signal(signum, handler, ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sigaltstack(const stack_t *ss, stack_t *old_ss, dfsan_label ss_label, + dfsan_label old_ss_label, dfsan_label *ret_label) { + int ret = sigaltstack(ss, old_ss); + if (ret != -1 && old_ss) + dfsan_set_label(0, old_ss, sizeof(*old_ss)); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfso_sigaltstack(const stack_t *ss, stack_t *old_ss, dfsan_label ss_label, + dfsan_label old_ss_label, dfsan_label *ret_label, + dfsan_origin ss_origin, dfsan_origin old_ss_origin, + dfsan_origin *ret_origin) { + return __dfsw_sigaltstack(ss, old_ss, ss_label, old_ss_label, ret_label); +} + +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 +int __dfso_gettimeofday(struct timeval *tv, struct timezone *tz, + dfsan_label tv_label, dfsan_label tz_label, + dfsan_label *ret_label, dfsan_origin tv_origin, + dfsan_origin tz_origin, dfsan_origin *ret_origin) { + return __dfsw_gettimeofday(tv, tz, tv_label, tz_label, ret_label); +} + +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 void *__dfso_memchr( + void *s, int c, size_t n, dfsan_label s_label, dfsan_label c_label, + dfsan_label n_label, dfsan_label *ret_label, dfsan_origin s_origin, + dfsan_origin c_origin, dfsan_origin n_origin, dfsan_origin *ret_origin) { + void *ret = __dfsw_memchr(s, c, n, s_label, c_label, n_label, ret_label); + if (flags().strict_data_dependencies) { + if (ret) + *ret_origin = s_origin; + } else { + size_t len = + ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1 + : n; + dfsan_origin o = dfsan_read_origin_of_first_taint(s, len); + *ret_origin = o ? o : (s_label ? s_origin : c_origin); + } + 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 *__dfso_strrchr( + char *s, int c, dfsan_label s_label, dfsan_label c_label, + dfsan_label *ret_label, dfsan_origin s_origin, dfsan_origin c_origin, + dfsan_origin *ret_origin) { + char *ret = __dfsw_strrchr(s, c, s_label, c_label, ret_label); + if (flags().strict_data_dependencies) { + if (ret) + *ret_origin = s_origin; + } else { + size_t s_len = strlen(s) + 1; + dfsan_origin o = dfsan_read_origin_of_first_taint(s, s_len); + *ret_origin = o ? o : (s_label ? s_origin : c_origin); + } + + 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 char *__dfso_strstr(char *haystack, char *needle, + dfsan_label haystack_label, + dfsan_label needle_label, + dfsan_label *ret_label, + dfsan_origin haystack_origin, + dfsan_origin needle_origin, + dfsan_origin *ret_origin) { + char *ret = + __dfsw_strstr(haystack, needle, haystack_label, needle_label, ret_label); + if (flags().strict_data_dependencies) { + if (ret) + *ret_origin = haystack_origin; + } else { + size_t needle_len = strlen(needle); + size_t len = ret ? ret + needle_len - haystack : strlen(haystack) + 1; + dfsan_origin o = dfsan_read_origin_of_first_taint(haystack, len); + if (o) { + *ret_origin = o; + } else { + o = dfsan_read_origin_of_first_taint(needle, needle_len + 1); + *ret_origin = o ? o : (haystack_label ? haystack_origin : needle_origin); + } + } + + 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 __dfso_nanosleep( + const struct timespec *req, struct timespec *rem, dfsan_label req_label, + dfsan_label rem_label, dfsan_label *ret_label, dfsan_origin req_origin, + dfsan_origin rem_origin, dfsan_origin *ret_origin) { + return __dfsw_nanosleep(req, rem, req_label, rem_label, ret_label); +} + +static void clear_msghdr_labels(size_t bytes_written, struct msghdr *msg, + int flags) { + dfsan_set_label(0, msg, sizeof(*msg)); + dfsan_set_label(0, msg->msg_name, msg->msg_namelen); + dfsan_set_label(0, msg->msg_control, msg->msg_controllen); + for (size_t i = 0; i < msg->msg_iovlen; ++i) { + struct iovec *iov = &msg->msg_iov[i]; + size_t iov_written = iov->iov_len; + + // When MSG_TRUNC is not set, we want to avoid setting 0 label on bytes that + // may not have changed, using bytes_written to bound the 0 label write. + // When MSG_TRUNC flag is set, bytes_written may be larger than the buffer, + // and should not be used as a bound. + if (!(MSG_TRUNC & flags)) { + if (bytes_written < iov->iov_len) { + iov_written = bytes_written; + } + bytes_written -= iov_written; + } + + dfsan_set_label(0, iov->iov_base, iov_written); + } +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_recvmmsg( + int sockfd, struct mmsghdr *msgvec, unsigned int vlen, int flags, + struct timespec *timeout, dfsan_label sockfd_label, + dfsan_label msgvec_label, dfsan_label vlen_label, dfsan_label flags_label, + dfsan_label timeout_label, dfsan_label *ret_label) { + int ret = recvmmsg(sockfd, msgvec, vlen, flags, timeout); + for (int i = 0; i < ret; ++i) { + dfsan_set_label(0, &msgvec[i].msg_len, sizeof(msgvec[i].msg_len)); + clear_msghdr_labels(msgvec[i].msg_len, &msgvec[i].msg_hdr, flags); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_recvmmsg( + int sockfd, struct mmsghdr *msgvec, unsigned int vlen, int flags, + struct timespec *timeout, dfsan_label sockfd_label, + dfsan_label msgvec_label, dfsan_label vlen_label, dfsan_label flags_label, + dfsan_label timeout_label, dfsan_label *ret_label, + dfsan_origin sockfd_origin, dfsan_origin msgvec_origin, + dfsan_origin vlen_origin, dfsan_origin flags_origin, + dfsan_origin timeout_origin, dfsan_origin *ret_origin) { + return __dfsw_recvmmsg(sockfd, msgvec, vlen, flags, timeout, sockfd_label, + msgvec_label, vlen_label, flags_label, timeout_label, + ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE ssize_t __dfsw_recvmsg( + int sockfd, struct msghdr *msg, int flags, dfsan_label sockfd_label, + dfsan_label msg_label, dfsan_label flags_label, dfsan_label *ret_label) { + ssize_t ret = recvmsg(sockfd, msg, flags); + if (ret >= 0) + clear_msghdr_labels(ret, msg, flags); + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE ssize_t __dfso_recvmsg( + int sockfd, struct msghdr *msg, int flags, dfsan_label sockfd_label, + dfsan_label msg_label, dfsan_label flags_label, dfsan_label *ret_label, + dfsan_origin sockfd_origin, dfsan_origin msg_origin, + dfsan_origin flags_origin, dfsan_origin *ret_origin) { + return __dfsw_recvmsg(sockfd, msg, flags, sockfd_label, msg_label, + flags_label, ret_label); +} + +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; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_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, dfsan_origin domain_origin, + dfsan_origin type_origin, dfsan_origin protocol_origin, + dfsan_origin sv_origin, dfsan_origin *ret_origin) { + return __dfsw_socketpair(domain, type, protocol, sv, domain_label, type_label, + protocol_label, sv_label, ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getsockopt( + int sockfd, int level, int optname, void *optval, socklen_t *optlen, + dfsan_label sockfd_label, dfsan_label level_label, + dfsan_label optname_label, dfsan_label optval_label, + dfsan_label optlen_label, dfsan_label *ret_label) { + int ret = getsockopt(sockfd, level, optname, optval, optlen); + if (ret != -1 && optval && optlen) { + dfsan_set_label(0, optlen, sizeof(*optlen)); + dfsan_set_label(0, optval, *optlen); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_getsockopt( + int sockfd, int level, int optname, void *optval, socklen_t *optlen, + dfsan_label sockfd_label, dfsan_label level_label, + dfsan_label optname_label, dfsan_label optval_label, + dfsan_label optlen_label, dfsan_label *ret_label, + dfsan_origin sockfd_origin, dfsan_origin level_origin, + dfsan_origin optname_origin, dfsan_origin optval_origin, + dfsan_origin optlen_origin, dfsan_origin *ret_origin) { + return __dfsw_getsockopt(sockfd, level, optname, optval, optlen, sockfd_label, + level_label, optname_label, optval_label, + optlen_label, ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getsockname( + int sockfd, struct sockaddr *addr, socklen_t *addrlen, + dfsan_label sockfd_label, dfsan_label addr_label, dfsan_label addrlen_label, + dfsan_label *ret_label) { + socklen_t origlen = addrlen ? *addrlen : 0; + int ret = getsockname(sockfd, addr, addrlen); + if (ret != -1 && addr && addrlen) { + socklen_t written_bytes = origlen < *addrlen ? origlen : *addrlen; + dfsan_set_label(0, addrlen, sizeof(*addrlen)); + dfsan_set_label(0, addr, written_bytes); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_getsockname( + int sockfd, struct sockaddr *addr, socklen_t *addrlen, + dfsan_label sockfd_label, dfsan_label addr_label, dfsan_label addrlen_label, + dfsan_label *ret_label, dfsan_origin sockfd_origin, + dfsan_origin addr_origin, dfsan_origin addrlen_origin, + dfsan_origin *ret_origin) { + return __dfsw_getsockname(sockfd, addr, addrlen, sockfd_label, addr_label, + addrlen_label, ret_label); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_getpeername( + int sockfd, struct sockaddr *addr, socklen_t *addrlen, + dfsan_label sockfd_label, dfsan_label addr_label, dfsan_label addrlen_label, + dfsan_label *ret_label) { + socklen_t origlen = addrlen ? *addrlen : 0; + int ret = getpeername(sockfd, addr, addrlen); + if (ret != -1 && addr && addrlen) { + socklen_t written_bytes = origlen < *addrlen ? origlen : *addrlen; + dfsan_set_label(0, addrlen, sizeof(*addrlen)); + dfsan_set_label(0, addr, written_bytes); + } + *ret_label = 0; + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_getpeername( + int sockfd, struct sockaddr *addr, socklen_t *addrlen, + dfsan_label sockfd_label, dfsan_label addr_label, dfsan_label addrlen_label, + dfsan_label *ret_label, dfsan_origin sockfd_origin, + dfsan_origin addr_origin, dfsan_origin addrlen_origin, + dfsan_origin *ret_origin) { + return __dfsw_getpeername(sockfd, addr, addrlen, sockfd_label, addr_label, + addrlen_label, ret_label); +} + +// Type of the function passed to dfsan_set_write_callback. +typedef void (*write_dfsan_callback_t)(int fd, const void *buf, ssize_t count); + +// 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_dfsan_callback_t write_callback = nullptr; +} write_callback_info; + +SANITIZER_INTERFACE_ATTRIBUTE void __dfsw_dfsan_set_write_callback( + write_dfsan_callback_t write_callback, dfsan_label write_callback_label, + dfsan_label *ret_label) { + write_callback_info.write_callback = write_callback; +} + +SANITIZER_INTERFACE_ATTRIBUTE void __dfso_dfsan_set_write_callback( + write_dfsan_callback_t write_callback, dfsan_label write_callback_label, + dfsan_label *ret_label, dfsan_origin write_callback_origin, + dfsan_origin *ret_origin) { + write_callback_info.write_callback = write_callback; +} + +static inline void setup_tls_args_for_write_callback( + dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label, + bool origins, dfsan_origin fd_origin, dfsan_origin buf_origin, + dfsan_origin count_origin) { + // The callback code will expect argument shadow labels in the args TLS, + // and origin labels in the origin args TLS. + // Previously this was done by a trampoline, but we want to remove this: + // https://github.com/llvm/llvm-project/issues/54172 + // + // Instead, this code is manually setting up the args TLS data. + // + // The offsets used need to correspond with the instrumentation code, + // see llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp + // DFSanFunction::getShadowForTLSArgument. + // https://github.com/llvm/llvm-project/blob/0acc9e4b5edd8b39ff3d4c6d0e17f02007671c4e/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp#L1684 + // https://github.com/llvm/llvm-project/blob/0acc9e4b5edd8b39ff3d4c6d0e17f02007671c4e/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp#L125 + // + // Here the arguments are all primitives, but it can be more complex + // to compute offsets for array/aggregate type arguments. + // + // TODO(browneee): Consider a builtin to improve maintainabliity. + // With a builtin, we would provide the argument labels via builtin, + // and the builtin would reuse parts of the instrumentation code to ensure + // that this code and the instrumentation can never be out of sync. + // Note: Currently DFSan instrumentation does not run on this code, so + // the builtin may need to be handled outside DFSan instrumentation. + dfsan_set_arg_tls(0, fd_label); + dfsan_set_arg_tls(1, buf_label); + dfsan_set_arg_tls(2, count_label); + if (origins) { + dfsan_set_arg_origin_tls(0, fd_origin); + dfsan_set_arg_origin_tls(1, buf_origin); + dfsan_set_arg_origin_tls(2, count_origin); + } +} + +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) { + setup_tls_args_for_write_callback(fd_label, buf_label, count_label, false, + 0, 0, 0); + write_callback_info.write_callback(fd, buf, count); + } + + *ret_label = 0; + return write(fd, buf, count); +} + +SANITIZER_INTERFACE_ATTRIBUTE int __dfso_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, + dfsan_origin fd_origin, dfsan_origin buf_origin, dfsan_origin count_origin, + dfsan_origin *ret_origin) { + if (write_callback_info.write_callback) { + setup_tls_args_for_write_callback(fd_label, buf_label, count_label, true, + fd_origin, buf_origin, count_origin); + write_callback_info.write_callback(fd, buf, count); + } + + *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), + num_scanned(-1), + skip(false) {} + + 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; + int num_scanned; + bool skip; +}; + +// 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, + dfsan_origin *va_origins, dfsan_origin *ret_origin, + 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)); + } + if (va_origins == nullptr) + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + else + dfsan_set_label_origin(*va_labels++, *va_origins++, + 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)); + } + if (va_origins == nullptr) + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + else + dfsan_set_label_origin(*va_labels++, *va_origins++, + formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 'c': + retval = formatter.format(va_arg(ap, int)); + if (va_origins == nullptr) + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + else + dfsan_set_label_origin(*va_labels++, *va_origins++, + formatter.str_cur(), + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + + case 's': { + char *arg = va_arg(ap, char *); + retval = formatter.format(arg); + if (va_origins) { + va_origins++; + dfsan_mem_origin_transfer(formatter.str_cur(), arg, + formatter.num_written_bytes(retval)); + } + va_labels++; + dfsan_mem_shadow_transfer(formatter.str_cur(), arg, + formatter.num_written_bytes(retval)); + end_fmt = true; + break; + } + + case 'p': + retval = formatter.format(va_arg(ap, void *)); + if (va_origins == nullptr) + dfsan_set_label(*va_labels++, formatter.str_cur(), + formatter.num_written_bytes(retval)); + else + dfsan_set_label_origin(*va_labels++, *va_origins++, + 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++; + if (va_origins) + va_origins++; + 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++; + if (va_origins) + va_origins++; + break; + + default: + break; + } + } + } + + if (retval < 0) { + return retval; + } + + formatter.fmt_cur++; + formatter.str_off += retval; + } + + *ret_label = 0; + if (ret_origin) + *ret_origin = 0; + + // Number of bytes written in total. + return formatter.str_off; +} + +// Scans a chunk either a constant string or a single format directive (e.g., +// '%.3f'). +struct Scanner { + Scanner(char *str_, const char *fmt_, size_t size_) + : str(str_), + str_off(0), + size(size_), + fmt_start(fmt_), + fmt_cur(fmt_), + width(-1), + num_scanned(0), + skip(false) {} + + // Consumes a chunk of ordinary characters. + // Returns number of matching ordinary characters. + // Returns -1 if the match failed. + // In format strings, a space will match multiple spaces. + int check_match_ordinary() { + char *tmp_fmt = build_format_string_with_n(); + int read_count = -1; + sscanf(str + str_off, tmp_fmt, &read_count); + free(tmp_fmt); + if (read_count > 0) { + str_off += read_count; + } + return read_count; + } + + int scan() { + char *tmp_fmt = build_format_string_with_n(); + int read_count = 0; + int retval = sscanf(str + str_off, tmp_fmt, &read_count); + free(tmp_fmt); + if (retval > 0) { + num_scanned += retval; + } + return read_count; + } + + template <typename T> + int scan(T arg) { + char *tmp_fmt = build_format_string_with_n(); + int read_count = 0; + int retval = sscanf(str + str_off, tmp_fmt, arg, &read_count); + free(tmp_fmt); + if (retval > 0) { + num_scanned += retval; + } + return read_count; + } + + // Adds %n onto current format string to measure length. + char *build_format_string_with_n() { + size_t fmt_size = fmt_cur - fmt_start + 1; + // +2 for %n, +1 for \0 + char *new_fmt = (char *)malloc(fmt_size + 2 + 1); + assert(new_fmt); + internal_memcpy(new_fmt, fmt_start, fmt_size); + new_fmt[fmt_size] = '%'; + new_fmt[fmt_size + 1] = 'n'; + new_fmt[fmt_size + 2] = '\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; + int num_scanned; + bool skip; +}; + +// This function is an inverse of format_buffer: we take the input buffer, +// scan it in search for format strings and store the results in the varargs. +// The labels are propagated from the input buffer to the varargs. +static int scan_buffer(char *str, size_t size, const char *fmt, + dfsan_label *va_labels, dfsan_label *ret_label, + dfsan_origin *str_origin, dfsan_origin *ret_origin, + va_list ap) { + Scanner scanner(str, fmt, size); + while (*scanner.fmt_cur) { + scanner.fmt_start = scanner.fmt_cur; + scanner.width = -1; + scanner.skip = false; + int read_count = 0; + void *dst_ptr = 0; + size_t write_size = 0; + if (*scanner.fmt_cur != '%') { + // Ordinary character and spaces. + // Consume all the characters until a '%' or the end of the string. + for (; *(scanner.fmt_cur + 1) && *(scanner.fmt_cur + 1) != '%'; + ++scanner.fmt_cur) { + } + if (scanner.check_match_ordinary() < 0) { + // The ordinary characters did not match. + break; + } + } else { + // Conversion directive. Consume all the characters until a conversion + // specifier or the end of the string. + bool end_fmt = false; + for (; *scanner.fmt_cur && !end_fmt;) { + switch (*++scanner.fmt_cur) { + case 'd': + case 'i': + case 'o': + case 'u': + case 'x': + case 'X': + if (scanner.skip) { + read_count = scanner.scan(); + } else { + switch (*(scanner.fmt_cur - 1)) { + case 'h': + // Also covers the 'hh' case (since the size of the arg is + // still an int). + dst_ptr = va_arg(ap, int *); + read_count = scanner.scan((int *)dst_ptr); + write_size = sizeof(int); + break; + case 'l': + if (scanner.fmt_cur - scanner.fmt_start >= 2 && + *(scanner.fmt_cur - 2) == 'l') { + dst_ptr = va_arg(ap, long long int *); + read_count = scanner.scan((long long int *)dst_ptr); + write_size = sizeof(long long int); + } else { + dst_ptr = va_arg(ap, long int *); + read_count = scanner.scan((long int *)dst_ptr); + write_size = sizeof(long int); + } + break; + case 'q': + dst_ptr = va_arg(ap, long long int *); + read_count = scanner.scan((long long int *)dst_ptr); + write_size = sizeof(long long int); + break; + case 'j': + dst_ptr = va_arg(ap, intmax_t *); + read_count = scanner.scan((intmax_t *)dst_ptr); + write_size = sizeof(intmax_t); + break; + case 'z': + case 't': + dst_ptr = va_arg(ap, size_t *); + read_count = scanner.scan((size_t *)dst_ptr); + write_size = sizeof(size_t); + break; + default: + dst_ptr = va_arg(ap, int *); + read_count = scanner.scan((int *)dst_ptr); + write_size = sizeof(int); + } + // get the label associated with the string at the corresponding + // place + dfsan_label l = dfsan_read_label( + scanner.str_cur(), scanner.num_written_bytes(read_count)); + dfsan_set_label(l, dst_ptr, write_size); + if (str_origin != nullptr) { + dfsan_set_label(l, dst_ptr, write_size); + size_t scan_count = scanner.num_written_bytes(read_count); + size_t size = scan_count > write_size ? write_size : scan_count; + dfsan_mem_origin_transfer(dst_ptr, scanner.str_cur(), size); + } + } + end_fmt = true; + + break; + + case 'a': + case 'A': + case 'e': + case 'E': + case 'f': + case 'F': + case 'g': + case 'G': + if (scanner.skip) { + read_count = scanner.scan(); + } else { + if (*(scanner.fmt_cur - 1) == 'L') { + dst_ptr = va_arg(ap, long double *); + read_count = scanner.scan((long double *)dst_ptr); + write_size = sizeof(long double); + } else if (*(scanner.fmt_cur - 1) == 'l') { + dst_ptr = va_arg(ap, double *); + read_count = scanner.scan((double *)dst_ptr); + write_size = sizeof(double); + } else { + dst_ptr = va_arg(ap, float *); + read_count = scanner.scan((float *)dst_ptr); + write_size = sizeof(float); + } + dfsan_label l = dfsan_read_label( + scanner.str_cur(), scanner.num_written_bytes(read_count)); + dfsan_set_label(l, dst_ptr, write_size); + if (str_origin != nullptr) { + dfsan_set_label(l, dst_ptr, write_size); + size_t scan_count = scanner.num_written_bytes(read_count); + size_t size = scan_count > write_size ? write_size : scan_count; + dfsan_mem_origin_transfer(dst_ptr, scanner.str_cur(), size); + } + } + end_fmt = true; + break; + + case 'c': + if (scanner.skip) { + read_count = scanner.scan(); + } else { + dst_ptr = va_arg(ap, char *); + read_count = scanner.scan((char *)dst_ptr); + write_size = sizeof(char); + dfsan_label l = dfsan_read_label( + scanner.str_cur(), scanner.num_written_bytes(read_count)); + dfsan_set_label(l, dst_ptr, write_size); + if (str_origin != nullptr) { + size_t scan_count = scanner.num_written_bytes(read_count); + size_t size = scan_count > write_size ? write_size : scan_count; + dfsan_mem_origin_transfer(dst_ptr, scanner.str_cur(), size); + } + } + end_fmt = true; + break; + + case 's': { + if (scanner.skip) { + read_count = scanner.scan(); + } else { + dst_ptr = va_arg(ap, char *); + read_count = scanner.scan((char *)dst_ptr); + if (1 == read_count) { + // special case: we have parsed a single string and we need to + // update read_count with the string size + read_count = strlen((char *)dst_ptr); + } + if (str_origin) + dfsan_mem_origin_transfer( + dst_ptr, scanner.str_cur(), + scanner.num_written_bytes(read_count)); + va_labels++; + dfsan_mem_shadow_transfer(dst_ptr, scanner.str_cur(), + scanner.num_written_bytes(read_count)); + } + end_fmt = true; + break; + } + + case 'p': + if (scanner.skip) { + read_count = scanner.scan(); + } else { + dst_ptr = va_arg(ap, void *); + read_count = + scanner.scan((int *)dst_ptr); // note: changing void* to int* + // since we need to call sizeof + write_size = sizeof(int); + + dfsan_label l = dfsan_read_label( + scanner.str_cur(), scanner.num_written_bytes(read_count)); + dfsan_set_label(l, dst_ptr, write_size); + if (str_origin != nullptr) { + dfsan_set_label(l, dst_ptr, write_size); + size_t scan_count = scanner.num_written_bytes(read_count); + size_t size = scan_count > write_size ? write_size : scan_count; + dfsan_mem_origin_transfer(dst_ptr, scanner.str_cur(), size); + } + } + end_fmt = true; + break; + + case 'n': { + if (!scanner.skip) { + int *ptr = va_arg(ap, int *); + *ptr = (int)scanner.str_off; + *va_labels++ = 0; + dfsan_set_label(0, ptr, sizeof(*ptr)); + if (str_origin != nullptr) + *str_origin++ = 0; + } + end_fmt = true; + break; + } + + case '%': + read_count = scanner.scan(); + end_fmt = true; + break; + + case '*': + scanner.skip = true; + break; + + default: + break; + } + } + } + + if (read_count < 0) { + // There was an error. + return read_count; + } + + scanner.fmt_cur++; + scanner.str_off += read_count; + } + + (void)va_labels; // Silence unused-but-set-parameter warning + *ret_label = 0; + if (ret_origin) + *ret_origin = 0; + + // Number of items scanned in total. + return scanner.num_scanned; +} + +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, INT32_MAX, format, va_labels, ret_label, nullptr, + nullptr, ap); + va_end(ap); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfso_sprintf(char *str, const char *format, dfsan_label str_label, + dfsan_label format_label, dfsan_label *va_labels, + dfsan_label *ret_label, dfsan_origin str_origin, + dfsan_origin format_origin, dfsan_origin *va_origins, + dfsan_origin *ret_origin, ...) { + va_list ap; + va_start(ap, ret_origin); + int ret = format_buffer(str, INT32_MAX, format, va_labels, ret_label, + va_origins, ret_origin, 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, nullptr, + nullptr, ap); + va_end(ap); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfso_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, dfsan_origin str_origin, + dfsan_origin size_origin, dfsan_origin format_origin, + dfsan_origin *va_origins, dfsan_origin *ret_origin, ...) { + va_list ap; + va_start(ap, ret_origin); + int ret = format_buffer(str, size, format, va_labels, ret_label, va_origins, + ret_origin, ap); + va_end(ap); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfsw_sscanf(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 = scan_buffer(str, ~0ul, format, va_labels, ret_label, nullptr, + nullptr, ap); + va_end(ap); + return ret; +} + +SANITIZER_INTERFACE_ATTRIBUTE +int __dfso_sscanf(char *str, const char *format, dfsan_label str_label, + dfsan_label format_label, dfsan_label *va_labels, + dfsan_label *ret_label, dfsan_origin str_origin, + dfsan_origin format_origin, dfsan_origin *va_origins, + dfsan_origin *ret_origin, ...) { + va_list ap; + va_start(ap, ret_origin); + int ret = scan_buffer(str, ~0ul, format, va_labels, ret_label, &str_origin, + ret_origin, ap); + va_end(ap); + return ret; +} + +WRAPPER_ALIAS(__isoc99_sscanf, sscanf) +WRAPPER_ALIAS(__isoc23_sscanf, sscanf) + +static void BeforeFork() { + StackDepotLockBeforeFork(); + ChainedOriginDepotLockBeforeFork(); +} + +static void AfterFork(bool fork_child) { + ChainedOriginDepotUnlockAfterFork(fork_child); + StackDepotUnlockAfterFork(fork_child); +} + +SANITIZER_INTERFACE_ATTRIBUTE +pid_t __dfsw_fork(dfsan_label *ret_label) { + pid_t pid = fork(); + *ret_label = 0; + return pid; +} + +SANITIZER_INTERFACE_ATTRIBUTE +pid_t __dfso_fork(dfsan_label *ret_label, dfsan_origin *ret_origin) { + BeforeFork(); + pid_t pid = __dfsw_fork(ret_label); + AfterFork(/* fork_child= */ pid == 0); + return pid; +} + +// 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, const uptr *beg, + const uptr *end) {} +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" |