// RUN: %clangxx_msan -O0 -g %s -o %t && %run %t // RUN: %clangxx_msan -O3 -g %s -o %t && %run %t // RUN: %clangxx_msan -DPOSITIVE -O0 -g %s -o %t && not %run %t 2>&1 | FileCheck %s // RUN: %clangxx_msan -DPOSITIVE -O3 -g %s -o %t && not %run %t 2>&1 | FileCheck %s #include <assert.h> #include <stdlib.h> #include <net/if.h> #include <stdio.h> #include <string.h> #include <sys/ioctl.h> #include <sys/socket.h> #include <unistd.h> int main(int argc, char **argv) { int fd = socket(AF_INET, SOCK_STREAM, 0); struct ifreq ifreqs[20]; struct ifconf ifc; ifc.ifc_ifcu.ifcu_req = ifreqs; #ifndef POSITIVE ifc.ifc_len = sizeof(ifreqs); #endif int res = ioctl(fd, SIOCGIFCONF, (void *)&ifc); // CHECK: Uninitialized bytes in ioctl{{.*}} at offset 0 inside [0x{{.*}}, 4) // CHECK: WARNING: MemorySanitizer: use-of-uninitialized-value // CHECK: #{{.*}} in main {{.*}}ioctl_custom.cc:[[@LINE-3]] assert(res == 0); for (int i = 0; i < ifc.ifc_len / sizeof(*ifc.ifc_ifcu.ifcu_req); ++i) printf("%d %zu %s\n", i, strlen(ifreqs[i].ifr_name), ifreqs[i].ifr_name); return 0; }