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 5 #include <features.h> 6 #include <assert.h> 7 #include <semaphore.h> 8 #include <string.h> 9 #include <stdint.h> 10 11 // musl and glibc's __HAVE_64B_ATOMICS==0 ports (e.g. arm, i386) use 32-bit sem 12 // values. 64-bit glibc ports defining sem_init@GLIBC_2.0 (mips64) use 32-bit as 13 // well, if the sem_init interceptor picks the oldest versioned symbol 14 // (glibc<2.36, see https://sourceware.org/PR14932). 15 #if !defined(__GLIBC__) || defined(__ILP32__) || \ 16 !__GLIBC_PREREQ(2, 36) && defined(__mips64__) 17 typedef unsigned semval_t; 18 #else 19 typedef uint64_t semval_t; 20 #endif 21 22 // glibc __HAVE_64B_ATOMICS==0 ports define a sem_init which shifts the value by 23 // 1 (https://sourceware.org/PR12674 glibc 2.21). The version is picked if 24 // either glibc>=2.36 or sem_init@GLIBC_2.0 is absent (arm and newer ports). 25 // 26 // The __GLIBC_PREREQ check is brittle in that it requires matched 27 // __GLIBC_PREREQ values for build time and run time. 28 #if defined(__GLIBC__) && defined(__ILP32__) && \ 29 (__GLIBC_PREREQ(2, 36) || (__GLIBC_PREREQ(2, 21) && !defined(__i386__) && \ 30 !defined(__mips__) && !defined(__powerpc__))) 31 # define GET_SEM_VALUE(V) ((V) >> 1) 32 #else 33 # define GET_SEM_VALUE(V) (V) 34 #endif 35 36 void my_sem_init(bool priv, int value, semval_t *a, unsigned char *b) { 37 sem_t sem; 38 memset(&sem, 0xAB, sizeof(sem)); 39 sem_init(&sem, priv, value); 40 41 char *p = (char *)&sem; 42 memcpy(a, p, sizeof(semval_t)); 43 memcpy(b, p + sizeof(semval_t), sizeof(char)); 44 45 sem_destroy(&sem); 46 } 47 48 int main() { 49 semval_t a; 50 unsigned char b; 51 52 my_sem_init(false, 42, &a, &b); 53 assert(GET_SEM_VALUE(a) == 42); 54 assert(b != 0xAB); 55 56 my_sem_init(true, 43, &a, &b); 57 assert(GET_SEM_VALUE(a) == 43); 58 assert(b != 0xAB); 59 } 60