1 // RUN: %clangxx_asan -O0 -mllvm -asan-instrument-dynamic-allocas %s -o %t 2 // RUN: %env_asan_opts=detect_stack_use_after_return=0 %run %t 2>&1 3 // 4 // REQUIRES: stable-runtime 5 6 // This testcase checks that allocas and VLAs inside loop are correctly unpoisoned. 7 8 #include <assert.h> 9 #include <stdint.h> 10 #include <stdlib.h> 11 #include "sanitizer/asan_interface.h" 12 13 // MSVC provides _alloca instead of alloca. 14 #if defined(_MSC_VER) && !defined(alloca) 15 # define alloca _alloca 16 #endif 17 18 #if defined(__sun__) && defined(__svr4__) 19 #include <alloca.h> 20 #endif 21 22 void *top, *bot; 23 foo(int len)24__attribute__((noinline)) void foo(int len) { 25 char x; 26 top = &x; 27 volatile char array[len]; 28 if (len) 29 array[0] = 0; 30 assert(!(reinterpret_cast<uintptr_t>(array) & 31L)); 31 alloca(len); 32 for (int i = 0; i < 32; ++i) { 33 volatile char array[i]; 34 if (i) 35 array[0] = 0; 36 bot = alloca(i); 37 assert(!(reinterpret_cast<uintptr_t>(bot) & 31L)); 38 } 39 } 40 main(int argc,char ** argv)41int main(int argc, char **argv) { 42 foo(32); 43 void *q = __asan_region_is_poisoned(bot, (char *)top - (char *)bot); 44 assert(!q); 45 return 0; 46 } 47