Implement a bunch of custom glibc wrappers & corresponding tests.

- Introduce several new custom glibc wrappers
- Implement some of the not yet implemented wrappers
- Refactor and extend the tests
- Add script to make sure all declare custom glibc wrappers are implemented & tested.

Patch by Lorenzo Martignoni!

Differential Revision: http://llvm-reviews.chandlerc.com/D2234

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@195381 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 969 insertions, 88 deletions

diff --git a/lib/dfsan/dfsan_custom.cc b/lib/dfsan/dfsan_custom.cc
index 6a132db06..b654d2f15 100644
--- a/lib/dfsan/dfsan_custom.cc
+++ b/lib/dfsan/dfsan_custom.cc
@@ -11,26 +11,35 @@
 //
 // This file defines the custom functions listed in done_abilist.txt.
 //===----------------------------------------------------------------------===//
+
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "sanitizer_common/sanitizer_linux.h"
 
 #include "dfsan/dfsan.h"
 
+#include <arpa/inet.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 <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/types.h>
+#include <sys/resource.h>
+#include <sys/select.h>
 #include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/types.h>
 #include <time.h>
 #include <unistd.h>
 
 using namespace __dfsan;
 
 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) {
@@ -338,4 +347,344 @@ SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr(
   return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi);
 }
 
+SANITIZER_INTERFACE_ATTRIBUTE
+char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label,
+                     dfsan_label buf_label, dfsan_label *ret_label) {
+  char *ret = ctime_r(timep, buf);
+  if (ret) {
+    dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf,
+                    strlen(buf) + 1);
+    *ret_label = buf_label;
+  } else {
+    *ret_label = 0;
+  }
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label,
+                   dfsan_label size_label, dfsan_label stream_label,
+                   dfsan_label *ret_label) {
+  char *ret = fgets(s, size, stream);
+  if (ret) {
+    dfsan_set_label(0, ret, strlen(ret) + 1);
+    *ret_label = s_label;
+  } else {
+    *ret_label = 0;
+  }
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label,
+                    dfsan_label size_label, dfsan_label *ret_label) {
+  char *ret = getcwd(buf, size);
+  if (ret) {
+    dfsan_set_label(0, ret, strlen(ret) + 1);
+    *ret_label = buf_label;
+  } else {
+    *ret_label = 0;
+  }
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+char *__dfsw_get_current_dir_name(dfsan_label *ret_label) {
+  char *ret = get_current_dir_name();
+  if (ret) {
+    dfsan_set_label(0, ret, strlen(ret) + 1);
+  }
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label,
+                       dfsan_label len_label, dfsan_label *ret_label) {
+  int ret = gethostname(name, len);
+  if (ret == 0) {
+    dfsan_set_label(0, name, strlen(name) + 1);
+  }
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_getrlimit(int resource, struct rlimit *rlim,
+                     dfsan_label resource_label, dfsan_label rlim_label,
+                     dfsan_label *ret_label) {
+  int ret = getrlimit(resource, rlim);
+  if (ret == 0) {
+    dfsan_set_label(0, rlim, sizeof(struct rlimit));
+  }
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label,
+                     dfsan_label usage_label, dfsan_label *ret_label) {
+  int ret = getrusage(who, usage);
+  if (ret == 0) {
+    dfsan_set_label(0, usage, sizeof(struct rusage));
+  }
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label,
+                    dfsan_label src_label, dfsan_label *ret_label) {
+  char *ret = strcpy(dest, src);
+  if (ret) {
+    internal_memcpy(shadow_for(dest), shadow_for(src),
+                    sizeof(dfsan_label) * (strlen(src) + 1));
+  }
+  *ret_label = dst_label;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+long int __dfsw_strtol(const char *nptr, char **endptr, int base,
+                       dfsan_label nptr_label, dfsan_label endptr_label,
+                       dfsan_label base_label, dfsan_label *ret_label) {
+  char *tmp_endptr;
+  long int ret = strtol(nptr, &tmp_endptr, base);
+  if (endptr) {
+    *endptr = tmp_endptr;
+  }
+  if (tmp_endptr > nptr) {
+    // If *tmp_endptr is '\0' include its label as well.
+    *ret_label = dfsan_union(
+        base_label,
+        dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
+  } else {
+    *ret_label = 0;
+  }
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+double __dfsw_strtod(const char *nptr, char **endptr,
+                       dfsan_label nptr_label, dfsan_label endptr_label,
+                       dfsan_label *ret_label) {
+  char *tmp_endptr;
+  double ret = strtod(nptr, &tmp_endptr);
+  if (endptr) {
+    *endptr = tmp_endptr;
+  }
+  if (tmp_endptr > nptr) {
+    // If *tmp_endptr is '\0' include its label as well.
+    *ret_label = dfsan_read_label(
+        nptr,
+        tmp_endptr - nptr + (*tmp_endptr ? 0 : 1));
+  } else {
+    *ret_label = 0;
+  }
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+long long int __dfsw_strtoll(const char *nptr, char **endptr, int base,
+                       dfsan_label nptr_label, dfsan_label endptr_label,
+                       dfsan_label base_label, dfsan_label *ret_label) {
+  char *tmp_endptr;
+  long long int ret = strtoll(nptr, &tmp_endptr, base);
+  if (endptr) {
+    *endptr = tmp_endptr;
+  }
+  if (tmp_endptr > nptr) {
+    // If *tmp_endptr is '\0' include its label as well.
+    *ret_label = dfsan_union(
+        base_label,
+        dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
+  } else {
+    *ret_label = 0;
+  }
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base,
+                       dfsan_label nptr_label, dfsan_label endptr_label,
+                       dfsan_label base_label, dfsan_label *ret_label) {
+  char *tmp_endptr;
+  unsigned long int ret = strtoul(nptr, &tmp_endptr, base);
+  if (endptr) {
+    *endptr = tmp_endptr;
+  }
+  if (tmp_endptr > nptr) {
+    // If *tmp_endptr is '\0' include its label as well.
+    *ret_label = dfsan_union(
+        base_label,
+        dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
+  } else {
+    *ret_label = 0;
+  }
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr,
+                                       dfsan_label nptr_label,
+                                       int base, dfsan_label endptr_label,
+                                       dfsan_label base_label,
+                                       dfsan_label *ret_label) {
+  char *tmp_endptr;
+  long long unsigned int ret = strtoull(nptr, &tmp_endptr, base);
+  if (endptr) {
+    *endptr = tmp_endptr;
+  }
+  if (tmp_endptr > nptr) {
+    // If *tmp_endptr is '\0' include its label as well.
+    *ret_label = dfsan_union(
+        base_label,
+        dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)));
+  } else {
+    *ret_label = 0;
+  }
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) {
+  time_t ret = time(t);
+  if (ret != (time_t) -1 && t) {
+    dfsan_set_label(0, t, sizeof(time_t));
+  }
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label,
+                     dfsan_label src_label, dfsan_label dst_label,
+                     dfsan_label *ret_label) {
+  int ret = inet_pton(af, src, dst);
+  if (ret == 1) {
+    dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst,
+                    af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr));
+  }
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result,
+                              dfsan_label timep_label, dfsan_label result_label,
+                              dfsan_label *ret_label) {
+  struct tm *ret = localtime_r(timep, result);
+  if (ret) {
+    dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result,
+                    sizeof(struct tm));
+    *ret_label = result_label;
+  } else {
+    *ret_label = 0;
+  }
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd,
+                      char *buf, size_t buflen, struct passwd **result,
+                      dfsan_label uid_label, dfsan_label pwd_label,
+                      dfsan_label buf_label, dfsan_label buflen_label,
+                      dfsan_label result_label, dfsan_label *ret_label) {
+  // Store the data in pwd, the strings referenced from pwd in buf, and the
+  // address of pwd in *result.  On failure, NULL is stored in *result.
+  int ret = getpwuid_r(uid, pwd, buf, buflen, result);
+  if (ret == 0) {
+    dfsan_set_label(0, pwd, sizeof(struct passwd));
+    dfsan_set_label(0, buf, strlen(buf) + 1);
+  }
+  *ret_label = 0;
+  dfsan_set_label(0, result, sizeof(struct passwd*));
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout,
+                dfsan_label dfs_label, dfsan_label nfds_label,
+                dfsan_label timeout_label, dfsan_label *ret_label) {
+  int ret = poll(fds, nfds, timeout);
+  if (ret >= 0) {
+    for (; nfds > 0; --nfds) {
+      dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents));
+    }
+  }
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds,
+                  fd_set *exceptfds, struct timeval *timeout,
+                  dfsan_label nfds_label, dfsan_label readfds_label,
+                  dfsan_label writefds_label, dfsan_label exceptfds_label,
+                  dfsan_label timeout_label, dfsan_label *ret_label) {
+  int ret = select(nfds, readfds, writefds, exceptfds, timeout);
+  // Clear everything (also on error) since their content is either set or
+  // undefined.
+  if (readfds) {
+    dfsan_set_label(0, readfds, sizeof(fd_set));
+  }
+  if (writefds) {
+    dfsan_set_label(0, writefds, sizeof(fd_set));
+  }
+  if (exceptfds) {
+    dfsan_set_label(0, exceptfds, sizeof(fd_set));
+  }
+  dfsan_set_label(0, timeout, sizeof(struct timeval));
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask,
+                             dfsan_label pid_label,
+                             dfsan_label cpusetsize_label,
+                             dfsan_label mask_label, dfsan_label *ret_label) {
+  int ret = sched_getaffinity(pid, cpusetsize, mask);
+  if (ret == 0) {
+    dfsan_set_label(0, mask, cpusetsize);
+  }
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label,
+                       dfsan_label *ret_label) {
+  int ret = sigemptyset(set);
+  dfsan_set_label(0, set, sizeof(sigset_t));
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_sigaction(int signum, const struct sigaction *act,
+                     struct sigaction *oldact, dfsan_label signum_label,
+                     dfsan_label act_label, dfsan_label oldact_label,
+                     dfsan_label *ret_label) {
+  int ret = sigaction(signum, act, oldact);
+  if (oldact) {
+    dfsan_set_label(0, oldact, sizeof(struct sigaction));
+  }
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz,
+                        dfsan_label tv_label, dfsan_label tz_label,
+                        dfsan_label *ret_label) {
+  int ret = gettimeofday(tv, tz);
+  if (tv) {
+    dfsan_set_label(0, tv, sizeof(struct timeval));
+  }
+  if (tz) {
+    dfsan_set_label(0, tz, sizeof(struct timezone));
+  }
+  *ret_label = 0;
+  return ret;
+}
 }
diff --git a/lib/dfsan/done_abilist.txt b/lib/dfsan/done_abilist.txt
index 52e0628aa..54b3935ae 100644
--- a/lib/dfsan/done_abilist.txt
+++ b/lib/dfsan/done_abilist.txt
@@ -103,23 +103,41 @@ fun:strerror=discard
 fun:syscall=discard
 fun:uselocale=discard
 fun:write=discard
+fun:dlclose=discard
+fun:__assert_fail=discard
 
 # Functions that produce output does not depend on the input (need to zero the
 # shadow manually).
 fun:calloc=custom
 fun:clock_gettime=custom
 fun:dlopen=custom
+fun:fgets=custom
 fun:fstat=custom
+fun:getcwd=custom
+fun:get_current_dir_name=custom
+fun:gethostname=custom
+fun:getrlimit=custom
+fun:getrusage=custom
 fun:pread=custom
 fun:read=custom
 fun:stat=custom
+fun:time=custom
 
 # Functions that produce an output that depend on the input (propagate the
 # shadow manually).
+fun:ctime_r=custom
+fun:inet_pton=custom
+fun:localtime_r=custom
 fun:memcpy=custom
 fun:memset=custom
+fun:strcpy=custom
 fun:strdup=custom
 fun:strncpy=custom
+fun:strtod=custom
+fun:strtol=custom
+fun:strtoll=custom
+fun:strtoul=custom
+fun:strtoull=custom
 
 # Functions that produce an output that is computed from the input, but is not
 # necessarily data dependent.
@@ -134,21 +152,19 @@ fun:strncmp=custom
 # Functions that take a callback (wrap the callback manually).
 fun:dl_iterate_phdr=custom
 
+fun:getpwuid_r=custom
+fun:poll=custom
+fun:sched_getaffinity=custom
+fun:select=custom
+fun:sigemptyset=custom
+fun:sigaction=custom
+fun:gettimeofday=custom
+
 # TODO: custom
 fun:snprintf=discard
 fun:vsnprintf=discard
 fun:asprintf=discard
 fun:qsort=discard
-fun:strtoll=discard
-fun:strtoull=discard
-fun:sigemptyset=discard
-fun:sigaction=discard
-fun:gettimeofday=discard
-fun:get_current_dir_name=discard
-fun:getpwuid_r=discard
-fun:poll=discard
-fun:sched_getaffinity=discard
-fun:select=discard
 
 ###############################################################################
 # pthread
diff --git a/lib/dfsan/lit_tests/custom.c b/lib/dfsan/lit_tests/custom.c
index c9fa93561..dd6d580a0 100644
--- a/lib/dfsan/lit_tests/custom.c
+++ b/lib/dfsan/lit_tests/custom.c
@@ -1,154 +1,620 @@
 // RUN: %clang_dfsan -m64 %s -o %t && %t
 // RUN: %clang_dfsan -mllvm -dfsan-args-abi -m64 %s -o %t && %t
 
-// Tests custom implementations of various libc functions.
+// Tests custom implementations of various glibc functions.
 
 #define _GNU_SOURCE
 #include <sanitizer/dfsan_interface.h>
+
+#include <arpa/inet.h>
 #include <assert.h>
+#include <fcntl.h>
 #include <link.h>
+#include <poll.h>
 #include <pthread.h>
-#include <string.h>
+#include <pwd.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
 #include <stdlib.h>
-#include <sys/types.h>
+#include <string.h>
+#include <sys/select.h>
+#include <sys/resource.h>
 #include <sys/stat.h>
-#include <fcntl.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <time.h>
 #include <unistd.h>
 
-void *ptcb(void *p) {
-  assert(p == (void *)1);
-  assert(dfsan_get_label((uintptr_t)p) == 0);
-  return (void *)2;
-}
+dfsan_label i_label = 0;
+dfsan_label j_label = 0;
+dfsan_label i_j_label = 0;
 
-int dlcb(struct dl_phdr_info *info, size_t size, void *data) {
-  assert(data == (void *)3);
-  assert(dfsan_get_label((uintptr_t)info) == 0);
-  assert(dfsan_get_label(size) == 0);
-  assert(dfsan_get_label((uintptr_t)data) == 0);
-  return 0;
-}
+#define ASSERT_ZERO_LABEL(data) \
+  assert(0 == dfsan_get_label((long) (data)))
 
-int main(void) {
+#define ASSERT_READ_ZERO_LABEL(ptr, size) \
+  assert(0 == dfsan_read_label(ptr, size))
+
+#define ASSERT_LABEL(data, label) \
+  assert(label == dfsan_get_label((long) (data)))
+
+#define ASSERT_READ_LABEL(ptr, size, label) \
+  assert(label == dfsan_read_label(ptr, size))
+
+void test_stat() {
   int i = 1;
-  dfsan_label i_label = dfsan_create_label("i", 0);
   dfsan_set_label(i_label, &i, sizeof(i));
 
-  int j = 2;
-  dfsan_label j_label = dfsan_create_label("j", 0);
-  dfsan_set_label(j_label, &j, sizeof(j));
-
   struct stat s;
   s.st_dev = i;
-  int rv = stat("/", &s);
-  assert(rv == 0);
-  assert(dfsan_get_label(s.st_dev) == 0);
+  assert(0 == stat("/", &s));
+  ASSERT_ZERO_LABEL(s.st_dev);
 
   s.st_dev = i;
-  rv = stat("/nonexistent", &s);
-  assert(rv == -1);
-  assert(dfsan_get_label(s.st_dev) == i_label);
+  assert(-1 == stat("/nonexistent", &s));
+  ASSERT_LABEL(s.st_dev, i_label);
+}
 
+void test_fstat() {
+  int i = 1;
+  dfsan_set_label(i_label, &i, sizeof(i));
+
+  struct stat s;
   int fd = open("/dev/zero", O_RDONLY);
   s.st_dev = i;
-  rv = fstat(fd, &s);
-  assert(rv == 0);
-  assert(dfsan_get_label(s.st_dev) == 0);
+  int rv = fstat(fd, &s);
+  assert(0 == rv);
+  ASSERT_ZERO_LABEL(s.st_dev);
+}
 
+void test_memcmp() {
   char str1[] = "str1", str2[] = "str2";
   dfsan_set_label(i_label, &str1[3], 1);
   dfsan_set_label(j_label, &str2[3], 1);
 
-  rv = memcmp(str1, str2, sizeof(str1));
+  int rv = memcmp(str1, str2, sizeof(str1));
   assert(rv < 0);
-  assert(dfsan_get_label(rv) == dfsan_union(i_label, j_label));
+  ASSERT_LABEL(rv, i_j_label);
+}
 
-  char strc[sizeof(str1)];
-  memcpy(strc, str1, sizeof(str1));
-  assert(dfsan_get_label(strc[0]) == 0);
-  assert(dfsan_get_label(strc[3]) == i_label);
+void test_memcpy() {
+  char str1[] = "str1";
+  char str2[sizeof(str1)];
+  dfsan_set_label(i_label, &str1[3], 1);
 
-  memset(strc, j, sizeof(strc));
-  assert(dfsan_get_label(strc[0]) == j_label);
-  assert(dfsan_get_label(strc[1]) == j_label);
-  assert(dfsan_get_label(strc[2]) == j_label);
-  assert(dfsan_get_label(strc[3]) == j_label);
-  assert(dfsan_get_label(strc[4]) == j_label);
+  ASSERT_ZERO_LABEL(memcpy(str2, str1, sizeof(str1)));
+  assert(0 == memcmp(str2, str1, sizeof(str1)));
+  ASSERT_ZERO_LABEL(str2[0]);
+  ASSERT_LABEL(str2[3], i_label);
+}
 
-  rv = strcmp(str1, str2);
+void test_memset() {
+  char buf[8];
+  int j = 'a';
+  dfsan_set_label(j_label, &j, sizeof(j));
+
+  ASSERT_ZERO_LABEL(memset(&buf, j, sizeof(buf)));
+  for (int i = 0; i < 8; ++i) {
+    ASSERT_LABEL(buf[i], j_label);
+    assert(buf[i] == 'a');
+  }
+}
+
+void test_strcmp() {
+  char str1[] = "str1", str2[] = "str2";
+  dfsan_set_label(i_label, &str1[3], 1);
+  dfsan_set_label(j_label, &str2[3], 1);
+
+  int rv = strcmp(str1, str2);
   assert(rv < 0);
-  assert(dfsan_get_label(rv) == dfsan_union(i_label, j_label));
+  ASSERT_LABEL(rv, i_j_label);
+}
+
+void test_strlen() {
+  char str1[] = "str1";
+  dfsan_set_label(i_label, &str1[3], 1);
+
+  int rv = strlen(str1);
+  assert(rv == 4);
+  ASSERT_LABEL(rv, i_label);
+}
+
+void test_strdup() {
+  char str1[] = "str1";
+  dfsan_set_label(i_label, &str1[3], 1);
 
   char *strd = strdup(str1);
-  assert(dfsan_get_label(strd[0]) == 0);
-  assert(dfsan_get_label(strd[3]) == i_label);
+  ASSERT_ZERO_LABEL(strd[0]);
+  ASSERT_LABEL(strd[3], i_label);
   free(strd);
+}
+
+void test_strncpy() {
+  char str1[] = "str1";
+  char str2[sizeof(str1)];
+  dfsan_set_label(i_label, &str1[3], 1);
+
+  char *strd = strncpy(str2, str1, 5);
+  assert(strd == str2);
+  assert(strcmp(str1, str2) == 0);
+  ASSERT_ZERO_LABEL(strd);
+  ASSERT_ZERO_LABEL(strd[0]);
+  ASSERT_ZERO_LABEL(strd[1]);
+  ASSERT_ZERO_LABEL(strd[2]);
+  ASSERT_LABEL(strd[3], i_label);
 
-  rv = strncmp(str1, str2, sizeof(str1));
+  strd = strncpy(str2, str1, 3);
+  assert(strd == str2);
+  assert(strncmp(str1, str2, 3) == 0);
+  ASSERT_ZERO_LABEL(strd);
+  ASSERT_ZERO_LABEL(strd[0]);
+  ASSERT_ZERO_LABEL(strd[1]);
+  ASSERT_ZERO_LABEL(strd[2]);
+}
+
+void test_strncmp() {
+  char str1[] = "str1", str2[] = "str2";
+  dfsan_set_label(i_label, &str1[3], 1);
+  dfsan_set_label(j_label, &str2[3], 1);
+
+  int rv = strncmp(str1, str2, sizeof(str1));
   assert(rv < 0);
-  assert(dfsan_get_label(rv) == dfsan_union(i_label, j_label));
+  ASSERT_LABEL(rv, dfsan_union(i_label, j_label));
 
   rv = strncmp(str1, str2, 3);
   assert(rv == 0);
-  assert(dfsan_get_label(rv) == 0);
+  ASSERT_ZERO_LABEL(rv);
+}
+
+void test_strcasecmp() {
+  char str1[] = "str1", str2[] = "str2", str3[] = "Str1";
+  dfsan_set_label(i_label, &str1[3], 1);
+  dfsan_set_label(j_label, &str2[3], 1);
+  dfsan_set_label(j_label, &str3[2], 1);
+
+  int rv = strcasecmp(str1, str2);
+  assert(rv < 0);
+  ASSERT_LABEL(rv, dfsan_union(i_label, j_label));
+
+  rv = strcasecmp(str1, str3);
+  assert(rv == 0);
+  ASSERT_LABEL(rv, dfsan_union(i_label, j_label));
+}
 
-  str1[0] = 'S';
+void test_strncasecmp() {
+  char str1[] = "Str1", str2[] = "str2";
+  dfsan_set_label(i_label, &str1[3], 1);
+  dfsan_set_label(j_label, &str2[3], 1);
 
-  rv = strncasecmp(str1, str2, sizeof(str1));
+  int rv = strncasecmp(str1, str2, sizeof(str1));
   assert(rv < 0);
-  assert(dfsan_get_label(rv) == dfsan_union(i_label, j_label));
+  ASSERT_LABEL(rv, dfsan_union(i_label, j_label));
 
   rv = strncasecmp(str1, str2, 3);
   assert(rv == 0);
-  assert(dfsan_get_label(rv) == 0);
+  ASSERT_ZERO_LABEL(rv);
+}
+
+void test_strchr() {
+  char str1[] = "str1";
+  dfsan_set_label(i_label, &str1[3], 1);
 
   char *crv = strchr(str1, 'r');
   assert(crv == &str1[2]);
-  assert(dfsan_get_label((uintptr_t)crv) == 0);
+  ASSERT_ZERO_LABEL(crv);
 
   crv = strchr(str1, '1');
   assert(crv == &str1[3]);
-  assert(dfsan_get_label((uintptr_t)crv) == i_label);
+  ASSERT_LABEL(crv, i_label);
 
   crv = strchr(str1, 'x');
-  assert(crv == 0);
-  assert(dfsan_get_label((uintptr_t)crv) == i_label);
+  assert(!crv);
+  ASSERT_LABEL(crv, i_label);
+}
 
+void test_calloc() {
   // With any luck this sequence of calls will cause calloc to return the same
   // pointer both times.  This is probably the best we can do to test this
   // function.
-  crv = calloc(4096, 1);
-  assert(dfsan_get_label(crv[0]) == 0);
+  char *crv = calloc(4096, 1);
+  ASSERT_ZERO_LABEL(crv[0]);
+  dfsan_set_label(i_label, crv, 100);
   free(crv);
 
   crv = calloc(4096, 1);
-  assert(dfsan_get_label(crv[0]) == 0);
+  ASSERT_ZERO_LABEL(crv[0]);
   free(crv);
+}
 
+void test_read() {
   char buf[16];
-  buf[0] = i;
-  buf[15] = j;
-  rv = read(fd, buf, sizeof(buf));
-  assert(rv == sizeof(buf));
-  assert(dfsan_get_label(buf[0]) == 0);
-  assert(dfsan_get_label(buf[15]) == 0);
+  dfsan_set_label(i_label, buf, 1);
+  dfsan_set_label(j_label, buf + 15, 1);
 
+  ASSERT_LABEL(buf[0], i_label);
+  ASSERT_LABEL(buf[15], j_label);
+
+  int fd = open("/dev/zero", O_RDONLY);
+  int rv = read(fd, buf, sizeof(buf));
+  assert(rv == sizeof(buf));
+  ASSERT_ZERO_LABEL(rv);
+  ASSERT_ZERO_LABEL(buf[0]);
+  ASSERT_ZERO_LABEL(buf[15]);
   close(fd);
-  fd = open("/bin/sh", O_RDONLY);
-  buf[0] = i;
-  buf[15] = j;
-  rv = pread(fd, buf, sizeof(buf), 0);
+}
+
+void test_pread() {
+  char buf[16];
+  dfsan_set_label(i_label, buf, 1);
+  dfsan_set_label(j_label, buf + 15, 1);
+
+  ASSERT_LABEL(buf[0], i_label);
+  ASSERT_LABEL(buf[15], j_label);
+
+  int fd = open("/bin/sh", O_RDONLY);
+  int rv = pread(fd, buf, sizeof(buf), 0);
   assert(rv == sizeof(buf));
-  assert(dfsan_get_label(buf[0]) == 0);
-  assert(dfsan_get_label(buf[15]) == 0);
+  ASSERT_ZERO_LABEL(rv);
+  ASSERT_ZERO_LABEL(buf[0]);
+  ASSERT_ZERO_LABEL(buf[15]);
+  close(fd);
+}
+
+void test_dlopen() {
+  void *map = dlopen(NULL, RTLD_NOW);
+  assert(map);
+  ASSERT_ZERO_LABEL(map);
+  dlclose(map);
+  map = dlopen("/nonexistent", RTLD_NOW);
+  assert(!map);
+  ASSERT_ZERO_LABEL(map);
+}
+
+void test_clock_gettime() {
+  struct timespec tp;
+  dfsan_set_label(j_label, ((char *)&tp) + 3, 1);
+  int t = clock_gettime(CLOCK_REALTIME, &tp);
+  assert(t == 0);
+  ASSERT_ZERO_LABEL(t);
+  ASSERT_ZERO_LABEL(((char *)&tp)[3]);
+}
+
+void test_ctime_r() {
+  char *buf = (char*) malloc(64);
+  time_t t = 0;
+
+  char *ret = ctime_r(&t, buf);
+  ASSERT_ZERO_LABEL(ret);
+  assert(buf == ret);
+  ASSERT_READ_ZERO_LABEL(buf, strlen(buf) + 1);
+
+  dfsan_set_label(i_label, &t, sizeof(t));
+  ret = ctime_r(&t, buf);
+  ASSERT_ZERO_LABEL(ret);
+  ASSERT_READ_LABEL(buf, strlen(buf) + 1, i_label);
+
+  t = 0;
+  dfsan_set_label(j_label, &buf, sizeof(&buf));
+  ret = ctime_r(&t, buf);
+  ASSERT_LABEL(ret, j_label);
+  ASSERT_READ_ZERO_LABEL(buf, strlen(buf) + 1);
+}
+
+void test_fgets() {
+  char *buf = (char*) malloc(128);
+  FILE *f = fopen("/etc/passwd", "r");
+  dfsan_set_label(j_label, buf, 1);
+  char *ret = fgets(buf, sizeof(buf), f);
+  assert(ret == buf);
+  ASSERT_ZERO_LABEL(ret);
+  ASSERT_READ_ZERO_LABEL(buf, 128);
+  dfsan_set_label(j_label, &buf, sizeof(&buf));
+  ret = fgets(buf, sizeof(buf), f);
+  ASSERT_LABEL(ret, j_label);
+  fclose(f);
+}
+
+void test_getcwd() {
+  char buf[1024];
+  char *ptr = buf;
+  dfsan_set_label(i_label, buf + 2, 2);
+  char* ret = getcwd(buf, sizeof(buf));
+  assert(ret == buf);
+  assert(ret[0] == '/');
+  ASSERT_READ_ZERO_LABEL(buf + 2, 2);
+  dfsan_set_label(i_label, &ptr, sizeof(ptr));
+  ret = getcwd(ptr, sizeof(buf));
+  ASSERT_LABEL(ret, i_label);
+}
+
+void test_get_current_dir_name() {
+  char* ret = get_current_dir_name();
+  assert(ret);
+  assert(ret[0] == '/');
+  ASSERT_READ_ZERO_LABEL(ret, strlen(ret) + 1);
+}
+
+void test_gethostname() {
+  char buf[1024];
+  dfsan_set_label(i_label, buf + 2, 2);
+  assert(gethostname(buf, sizeof(buf)) == 0);
+  ASSERT_READ_ZERO_LABEL(buf + 2, 2);
+}
+
+void test_getrlimit() {
+  struct rlimit rlim;
+  dfsan_set_label(i_label, &rlim, sizeof(rlim));
+  assert(getrlimit(RLIMIT_CPU, &rlim) == 0);
+  ASSERT_READ_ZERO_LABEL(&rlim, sizeof(rlim));
+}
+
+void test_getrusage() {
+  struct rusage usage;
+  dfsan_set_label(i_label, &usage, sizeof(usage));
+  assert(getrusage(RUSAGE_SELF, &usage) == 0);
+  ASSERT_READ_ZERO_LABEL(&usage, sizeof(usage));
+}
+
+void test_strcpy() {
+  char src[] = "hello world";
+  char dst[sizeof(src) + 2];
+  dfsan_set_label(0, src, sizeof(src));
+  dfsan_set_label(0, dst, sizeof(dst));
+  dfsan_set_label(i_label, src + 2, 1);
+  dfsan_set_label(j_label, src + 3, 1);
+  dfsan_set_label(j_label, dst + 4, 1);
+  dfsan_set_label(i_label, dst + 12, 1);
+  char *ret = strcpy(dst, src);
+  assert(ret == dst);
+  assert(strcmp(src, dst) == 0);
+  for (int i = 0; i < strlen(src) + 1; ++i) {
+    assert(dfsan_get_label(dst[i]) == dfsan_get_label(src[i]));
+  }
+  // Note: if strlen(src) + 1 were used instead to compute the first untouched
+  // byte of dest, the label would be I|J. This is because strlen() might
+  // return a non-zero label, and because by default pointer labels are not
+  // ignored on loads.
+  ASSERT_LABEL(dst[12], i_label);
+}
+
+void test_strtol() {
+  char buf[] = "1234578910";
+  char *endptr = NULL;
+  dfsan_set_label(i_label, buf + 1, 1);
+  dfsan_set_label(j_label, buf + 10, 1);
+  long int ret = strtol(buf, &endptr, 10);
+  assert(ret == 1234578910);
+  assert(endptr == buf + 10);
+  ASSERT_LABEL(ret, i_j_label);
+}
+
+void test_strtoll() {
+  char buf[] = "1234578910 ";
+  char *endptr = NULL;
+  dfsan_set_label(i_label, buf + 1, 1);
+  dfsan_set_label(j_label, buf + 2, 1);
+  long long int ret = strtoll(buf, &endptr, 10);
+  assert(ret == 1234578910);
+  assert(endptr == buf + 10);
+  ASSERT_LABEL(ret, i_j_label);
+}
+
+void test_strtoul() {
+  char buf[] = "0xffffffffffffaa";
+  char *endptr = NULL;
+  dfsan_set_label(i_label, buf + 1, 1);
+  dfsan_set_label(j_label, buf + 2, 1);
+  long unsigned int ret = strtol(buf, &endptr, 16);
+  assert(ret == 72057594037927850);
+  assert(endptr == buf + 16);
+  ASSERT_LABEL(ret, i_j_label);
+}
+
+void test_strtoull() {
+  char buf[] = "0xffffffffffffffaa";
+  char *endptr = NULL;
+  dfsan_set_label(i_label, buf + 1, 1);
+  dfsan_set_label(j_label, buf + 2, 1);
+  long long unsigned int ret = strtoull(buf, &endptr, 16);
+  assert(ret == 0xffffffffffffffaa);
+  assert(endptr == buf + 18);
+  ASSERT_LABEL(ret, i_j_label);
+}
+
+void test_strtod() {
+  char buf[] = "12345.76 foo";
+  char *endptr = NULL;
+  dfsan_set_label(i_label, buf + 1, 1);
+  dfsan_set_label(j_label, buf + 6, 1);
+  double ret = strtod(buf, &endptr);
+  assert(ret == 12345.76);
+  assert(endptr == buf + 8);
+  ASSERT_LABEL(ret, i_j_label);
+}
+
+void test_time() {
+  time_t t = 0;
+  dfsan_set_label(i_label, &t, 1);
+  time_t ret = time(&t);
+  assert(ret == t);
+  assert(ret > 0);
+  ASSERT_ZERO_LABEL(t);
+}
+
+void test_inet_pton() {
+  char addr4[] = "127.0.0.1";
+  dfsan_set_label(i_label, addr4 + 3, 1);
+  struct in_addr in4;
+  int ret4 = inet_pton(AF_INET, addr4, &in4);
+  assert(ret4 == 1);
+  ASSERT_READ_LABEL(&in4, sizeof(in4), i_label);
+  assert(in4.s_addr == 0x0100007f);
+
+  char addr6[] = "::1";
+  dfsan_set_label(j_label, addr6 + 3, 1);
+  struct in6_addr in6;
+  int ret6 = inet_pton(AF_INET6, addr6, &in6);
+  assert(ret6 == 1);
+  ASSERT_READ_LABEL(((char *) &in6) + sizeof(in6) - 1, 1, j_label);
+}
+
+void test_localtime_r() {
+  time_t t0 = 1384800998;
+  struct tm t1;
+  dfsan_set_label(i_label, &t0, sizeof(t0));
+  struct tm* ret = localtime_r(&t0, &t1);
+  assert(ret == &t1);
+  assert(t1.tm_min == 56);
+  ASSERT_LABEL(t1.tm_mon, i_label);
+}
+
+void test_getpwuid_r() {
+  struct passwd pwd;
+  char buf[1024];
+  struct passwd *result;
+
+  dfsan_set_label(i_label, &pwd, 4);
+  int ret = getpwuid_r(0, &pwd, buf, sizeof(buf), &result);
+  assert(ret == 0);
+  assert(strcmp(pwd.pw_name, "root") == 0);
+  assert(result == &pwd);
+  ASSERT_READ_ZERO_LABEL(&pwd, 4);
+}
+
+void test_poll() {
+  struct pollfd fd;
+  fd.fd = 0;
+  fd.events = POLLIN;
+  dfsan_set_label(i_label, &fd.revents, sizeof(fd.revents));
+  int ret = poll(&fd, 1, 1);
+  ASSERT_ZERO_LABEL(fd.revents);
+  assert(ret >= 0);
+}
+
+void test_select() {
+  struct timeval t;
+  fd_set fds;
+  t.tv_sec = 2;
+  FD_SET(0, &fds);
+  dfsan_set_label(i_label, &fds, sizeof(fds));
+  dfsan_set_label(j_label, &t, sizeof(t));
+  int ret = select(1, &fds, NULL, NULL, &t);
+  assert(ret >= 0);
+  ASSERT_ZERO_LABEL(t.tv_sec);
+  ASSERT_READ_ZERO_LABEL(&fds, sizeof(fds));
+}
+
+void test_sched_getaffinity() {
+  cpu_set_t mask;
+  dfsan_set_label(j_label, &mask, 1);
+  int ret = sched_getaffinity(0, sizeof(mask), &mask);
+  assert(ret == 0);
+  ASSERT_READ_ZERO_LABEL(&mask, sizeof(mask));
+}
+
+void test_sigemptyset() {
+  sigset_t set;
+  dfsan_set_label(j_label, &set, 1);
+  int ret = sigemptyset(&set);
+  assert(ret == 0);
+  ASSERT_READ_ZERO_LABEL(&set, sizeof(set));
+}
 
+void test_sigaction() {
+  struct sigaction oldact;
+  dfsan_set_label(j_label, &oldact, 1);
+  int ret = sigaction(SIGUSR1, NULL, &oldact);
+  assert(ret == 0);
+  ASSERT_READ_ZERO_LABEL(&oldact, sizeof(oldact));
+}
+
+void test_gettimeofday() {
+  struct timeval tv;
+  struct timezone tz;
+  dfsan_set_label(i_label, &tv, sizeof(tv));
+  dfsan_set_label(j_label, &tz, sizeof(tz));
+  int ret = gettimeofday(&tv, &tz);
+  assert(ret == 0);
+  ASSERT_READ_ZERO_LABEL(&tv, sizeof(tv));
+  ASSERT_READ_ZERO_LABEL(&tz, sizeof(tz));
+}
+
+void *pthread_create_test_cb(void *p) {
+  assert(p == (void *)1);
+  ASSERT_ZERO_LABEL(p);
+  return (void *)2;
+}
+
+void test_pthread_create() {
   pthread_t pt;
-  pthread_create(&pt, 0, ptcb, (void *)1);
+  pthread_create(&pt, 0, pthread_create_test_cb, (void *)1);
   void *cbrv;
   pthread_join(pt, &cbrv);
   assert(cbrv == (void *)2);
+}
 
-  dl_iterate_phdr(dlcb, (void *)3);
-
+int dl_iterate_phdr_test_cb(struct dl_phdr_info *info, size_t size,
+                            void *data) {
+  assert(data == (void *)3);
+  ASSERT_ZERO_LABEL(info);
+  ASSERT_ZERO_LABEL(size);
+  ASSERT_ZERO_LABEL(data);
   return 0;
 }
+
+void test_dl_iterate_phdr() {
+  dl_iterate_phdr(dl_iterate_phdr_test_cb, (void *)3);
+}
+
+int main(void) {
+  i_label = dfsan_create_label("i", 0);
+  j_label = dfsan_create_label("j", 0);
+  i_j_label = dfsan_union(i_label, j_label);
+
+  test_calloc();
+  test_clock_gettime();
+  test_dlopen();
+  test_fstat();
+  test_memcmp();
+  test_memcpy();
+  test_memset();
+  test_pread();
+  test_read();
+  test_stat();
+  test_strcasecmp();
+  test_strchr();
+  test_strcmp();
+  test_strdup();
+  test_strlen();
+  test_strncasecmp();
+  test_strncmp();
+  test_strncpy();
+
+  test_ctime_r();
+  test_fgets();
+  test_getcwd();
+  test_get_current_dir_name();
+  test_gethostname();
+  test_getrlimit();
+  test_getrusage();
+  test_strcpy();
+  test_strtol();
+  test_strtoll();
+  test_strtod();
+  test_strtoul();
+  test_strtoull();
+  test_time();
+  test_inet_pton();
+  test_localtime_r();
+  test_getpwuid_r();
+  test_poll();
+  test_select();
+  test_sched_getaffinity();
+  test_sigemptyset();
+  test_sigaction();
+  test_gettimeofday();
+
+  test_pthread_create();
+  test_dl_iterate_phdr();
+}
diff --git a/lib/dfsan/scripts/check_custom_wrappers.sh b/lib/dfsan/scripts/check_custom_wrappers.sh
new file mode 100755
index 000000000..47a2c45e1
--- /dev/null
+++ b/lib/dfsan/scripts/check_custom_wrappers.sh
@@ -0,0 +1,50 @@
+#!/bin/bash
+
+DFSAN_DIR=$(dirname "$0")/../
+DFSAN_CUSTOM_TESTS=${DFSAN_DIR}/lit_tests/custom.c
+DFSAN_CUSTOM_WRAPPERS=${DFSAN_DIR}/dfsan_custom.cc
+DFSAN_ABI_LIST=${DFSAN_DIR}/done_abilist.txt
+
+DIFFOUT=$(mktemp -q /tmp/tmp.XXXXXXXXXX)
+ERRORLOG=$(mktemp -q /tmp/tmp.XXXXXXXXXX)
+
+on_exit() {
+  rm -f ${DIFFOUT} 2> /dev/null
+  rm -f ${ERRORLOG} 2> /dev/null
+}
+
+trap on_exit EXIT
+
+diff \
+  <(grep "^fun:.*=custom" ${DFSAN_ABI_LIST} | grep -v "dfsan_get_label" \
+    | sed "s/^fun:\(.*\)=custom.*/\1/" | sort ) \
+  <(grep "__dfsw.*(" ${DFSAN_CUSTOM_WRAPPERS} \
+    | sed "s/.*__dfsw_\(.*\)(.*/\1/" \
+    | sort) > ${DIFFOUT}
+if [ $? -ne 0 ]
+then
+  echo -n "The following differences between the ABI list and ">> ${ERRORLOG}
+  echo "the implemented custom wrappers have been found:" >> ${ERRORLOG}
+  cat ${DIFFOUT} >> ${ERRORLOG}
+fi
+
+diff \
+  <(grep __dfsw_ ${DFSAN_CUSTOM_WRAPPERS} \
+    | sed "s/.*__dfsw_\([^(]*\).*/\1/" \
+    | sort) \
+  <(grep "^\\s*test_.*();" ${DFSAN_CUSTOM_TESTS} \
+    | sed "s/.*test_\(.*\)();/\1/" \
+    | sort) > ${DIFFOUT}
+if [ $? -ne 0 ]
+then
+  echo -n "The following differences between the implemented " >> ${ERRORLOG}
+  echo "custom wrappers and the tests have been found:" >> ${ERRORLOG}
+  cat ${DIFFOUT} >> ${ERRORLOG}
+fi
+
+if [[ -s ${ERRORLOG} ]]
+then
+  cat ${ERRORLOG}
+  exit 1
+fi
+