1 // RUN: %clangxx_msan -std=c++11 -O0 %s -o %t && %run %t 2 // RUN: %clangxx_msan -std=c++11 -O0 %s -o %t -DPOSITIVE && not %run %t |& FileCheck %s 3 4 #include <assert.h> 5 #include <dlfcn.h> 6 #include <sanitizer/msan_interface.h> 7 #include <stdio.h> 8 #include <string.h> 9 #include <sys/types.h> 10 #include <sys/uio.h> 11 #include <unistd.h> 12 13 typedef ssize_t (*process_vm_readwritev_fn)(pid_t, const iovec *, unsigned long, 14 const iovec *, unsigned long, 15 unsigned long); 16 17 int main(void) { 18 // This requires glibc 2.15. 19 process_vm_readwritev_fn libc_process_vm_readv = 20 (process_vm_readwritev_fn)dlsym(RTLD_NEXT, "process_vm_readv"); 21 if (!libc_process_vm_readv) { 22 // Exit with success, emulating the expected output. 23 #ifdef POSITIVE 24 printf("process_vm_readv not found!\n"); 25 printf( 26 "WARNING: MemorySanitizer: use-of-uninitialized-value (not really)\n"); 27 return 1; 28 #else 29 return 0; 30 #endif 31 } 32 33 process_vm_readwritev_fn process_vm_readv = 34 (process_vm_readwritev_fn)dlsym(RTLD_DEFAULT, "process_vm_readv"); 35 process_vm_readwritev_fn process_vm_writev = 36 (process_vm_readwritev_fn)dlsym(RTLD_DEFAULT, "process_vm_writev"); 37 38 char a[100]; 39 memset(a, 0xab, 100); 40 41 char b[100]; 42 iovec iov_a[] = {{(void *)a, 20}, (void *)(a + 50), 10}; 43 iovec iov_b[] = {{(void *)(b + 10), 10}, (void *)(b + 30), 20}; 44 45 __msan_poison(&b, sizeof(b)); 46 ssize_t res = process_vm_readv(getpid(), iov_b, 2, iov_a, 2, 0); 47 assert(res == 30); 48 __msan_check_mem_is_initialized(b + 10, 10); 49 __msan_check_mem_is_initialized(b + 30, 20); 50 assert(__msan_test_shadow(b + 9, 1) == 0); 51 assert(__msan_test_shadow(b + 20, 1) == 0); 52 assert(__msan_test_shadow(b + 29, 1) == 0); 53 assert(__msan_test_shadow(b + 50, 1) == 0); 54 55 #ifdef POSITIVE 56 __msan_unpoison(&b, sizeof(b)); 57 __msan_poison(b + 32, 1); 58 res = process_vm_writev(getpid(), iov_b, 2, iov_a, 2, 0); 59 // CHECK: WARNING: MemorySanitizer: use-of-uninitialized-value 60 #else 61 __msan_unpoison(&b, sizeof(b)); 62 res = process_vm_writev(getpid(), iov_b, 2, iov_a, 2, 0); 63 assert(res == 30); 64 #endif 65 66 return 0; 67 } 68
