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
my_sem_init(bool priv,int value,semval_t * a,unsigned char * b)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
main()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