1 files changed, 62 insertions, 0 deletions
diff --git a/compiler-rt/test/sanitizer_common/TestCases/Linux/sem_init_glibc.cpp b/compiler-rt/test/sanitizer_common/TestCases/Linux/sem_init_glibc.cpp
new file mode 100644
index 00000000000..d623ccabb5b
--- /dev/null
+++ b/compiler-rt/test/sanitizer_common/TestCases/Linux/sem_init_glibc.cpp
@@ -0,0 +1,62 @@
+// RUN: %clangxx -O0 -g %s -lutil -o %t && %run %t
+// This test depends on the glibc layout of struct sem_t and checks that we
+// don't leave sem_t::private uninitialized.
+// UNSUPPORTED: android, lsan-x86, ubsan, target-is-mips64, target-is-mips64el
+#include <features.h>
+#include <assert.h>
+#include <semaphore.h>
+#include <string.h>
+#include <stdint.h>
+
+// On powerpc64be semval_t must be 64 bits even with "old" versions of glibc.
+#if __PPC64__ && __BIG_ENDIAN__
+typedef uint64_t semval_t;
+
+// This condition needs to correspond to __HAVE_64B_ATOMICS macro in glibc.
+#elif (defined(__x86_64__) || defined(__aarch64__) || defined(__powerpc64__) || \
+     defined(__s390x__) || defined(__sparc64__) || defined(__alpha__) || \
+     defined(__ia64__) || defined(__m68k__)) && __GLIBC_PREREQ(2, 21)
+typedef uint64_t semval_t;
+#else
+typedef unsigned semval_t;
+#endif
+
+// glibc 2.21 has introduced some changes in the way the semaphore value is
+// handled for 32-bit platforms, but since these changes are not ABI-breaking
+// they are not versioned. On newer platforms such as ARM, there is only one
+// version of the symbol, so it's enough to check the glibc version. However,
+// for old platforms such as i386, glibc contains two or even three versions of
+// the sem_init symbol, and the sanitizers always pick the oldest one.
+// Therefore, it is not enough to rely on the __GLIBC_PREREQ macro - we should
+// instead check the platform as well to make sure we only expect the new
+// behavior on platforms where the older symbols do not exist.
+#if defined(__arm__) && __GLIBC_PREREQ(2, 21)
+#define GET_SEM_VALUE(V) ((V) >> 1)
+#else
+#define GET_SEM_VALUE(V) (V)
+#endif
+
+void my_sem_init(bool priv, int value, semval_t *a, unsigned char *b) {
+  sem_t sem;
+  memset(&sem, 0xAB, sizeof(sem));
+  sem_init(&sem, priv, value);
+
+  char *p = (char *)&sem;
+  memcpy(a, p, sizeof(semval_t));
+  memcpy(b, p + sizeof(semval_t), sizeof(char));
+
+  sem_destroy(&sem);
+}
+
+int main() {
+  semval_t a;
+  unsigned char b;
+
+  my_sem_init(false, 42, &a, &b);
+  assert(GET_SEM_VALUE(a) == 42);
+  assert(b != 0xAB);
+
+  my_sem_init(true, 43, &a, &b);
+  assert(GET_SEM_VALUE(a) == 43);
+  assert(b != 0xAB);
+}