compiler-rt/test/sanitizer_common/TestCases/Linux/sem_init_glibc.cpp

   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 }