1 // RUN: %clangxx -O0 -g %s -lutil -o %t && %run %t 2 // This test depends on the glibc layout of struct sem_t and checks that we 3 // don't leave sem_t::private uninitialized. 4 // UNSUPPORTED: android, lsan-x86, ubsan, target-is-mips64, target-is-mips64el 5 #include <features.h> 6 #include <assert.h> 7 #include <semaphore.h> 8 #include <string.h> 9 #include <stdint.h> 10 11 // On powerpc64be semval_t must be 64 bits even with "old" versions of glibc. 12 #if __PPC64__ && __BIG_ENDIAN__ 13 typedef uint64_t semval_t; 14 15 // This condition needs to correspond to __HAVE_64B_ATOMICS macro in glibc. 16 #elif (defined(__x86_64__) || defined(__aarch64__) || defined(__powerpc64__) || \ 17 defined(__s390x__) || defined(__sparc64__) || defined(__alpha__) || \ 18 defined(__ia64__) || defined(__m68k__)) && __GLIBC_PREREQ(2, 21) 19 typedef uint64_t semval_t; 20 #else 21 typedef unsigned semval_t; 22 #endif 23 24 // glibc 2.21 has introduced some changes in the way the semaphore value is 25 // handled for 32-bit platforms, but since these changes are not ABI-breaking 26 // they are not versioned. On newer platforms such as ARM, there is only one 27 // version of the symbol, so it's enough to check the glibc version. However, 28 // for old platforms such as i386, glibc contains two or even three versions of 29 // the sem_init symbol, and the sanitizers always pick the oldest one. 30 // Therefore, it is not enough to rely on the __GLIBC_PREREQ macro - we should 31 // instead check the platform as well to make sure we only expect the new 32 // behavior on platforms where the older symbols do not exist. 33 #if defined(__arm__) && __GLIBC_PREREQ(2, 21) 34 #define GET_SEM_VALUE(V) ((V) >> 1) 35 #else 36 #define GET_SEM_VALUE(V) (V) 37 #endif 38 39 void my_sem_init(bool priv, int value, semval_t *a, unsigned char *b) { 40 sem_t sem; 41 memset(&sem, 0xAB, sizeof(sem)); 42 sem_init(&sem, priv, value); 43 44 char *p = (char *)&sem; 45 memcpy(a, p, sizeof(semval_t)); 46 memcpy(b, p + sizeof(semval_t), sizeof(char)); 47 48 sem_destroy(&sem); 49 } 50 51 int main() { 52 semval_t a; 53 unsigned char b; 54 55 my_sem_init(false, 42, &a, &b); 56 assert(GET_SEM_VALUE(a) == 42); 57 assert(b != 0xAB); 58 59 my_sem_init(true, 43, &a, &b); 60 assert(GET_SEM_VALUE(a) == 43); 61 assert(b != 0xAB); 62 } 63