1 // Test that out-of-scope local variables are ignored by LSan. 2 3 // LSan-in-ASan fails at -O0 on aarch64, because the stack use-after-return 4 // instrumentation stashes the argument to `PutPointerOnStaleStack` on the stack 5 // in order to conditionally call __asan_stack_malloc. This subverts our 6 // expectations for this test, where we assume the pointer is never stashed 7 // except at the bottom of the dead frame. Building at -O1 or greater solves 8 // this problem, because the compiler is smart enough to stash the argument in a 9 // callee-saved register for rematerialization instead. 10 // RUN: %clangxx_lsan -O1 %s -o %t 11 12 // RUN: %env_lsan_opts="report_objects=1:use_registers=0:use_stacks=1" not %run %t 2>&1 | FileCheck %s 13 // RUN: %env_lsan_opts="report_objects=1:use_registers=0:use_stacks=1:exitcode=0" %run %t 2>&1 | FileCheck --check-prefix=CHECK-sanity %s 14 // 15 // x86 passes parameters through stack that may lead to false negatives 16 // The same applies to s390x register save areas. 17 // UNSUPPORTED: x86,i686,powerpc64,arm,s390x 18 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include "sanitizer_common/print_address.h" 22 23 void **pp; 24 25 // Put pointer far enough on the stack that LSan has space to run in without 26 // overwriting it. 27 // Hopefully the argument p will be passed on a register, saving us from false 28 // negatives. 29 __attribute__((noinline)) 30 void *PutPointerOnStaleStack(void *p) { 31 void *locals[2048]; 32 locals[0] = p; 33 pp = &locals[0]; 34 print_address("Test alloc: ", 1, locals[0]); 35 return 0; 36 } 37 38 int main() { 39 PutPointerOnStaleStack(malloc(1337)); 40 return 0; 41 } 42 43 // This must run after LSan, to ensure LSan didn't overwrite the pointer before 44 // it had a chance to see it. If LSan is invoked with atexit(), this works. 45 // Otherwise, we need a different method. 46 __attribute__((destructor)) 47 __attribute__((no_sanitize_address)) 48 void ConfirmPointerHasSurvived() { 49 print_address("Value after LSan: ", 1, *pp); 50 } 51 // CHECK: Test alloc: [[ADDR:0x[0-9,a-f]+]] 52 // CHECK-sanity: Test alloc: [[ADDR:0x[0-9,a-f]+]] 53 // CHECK: LeakSanitizer: detected memory leaks 54 // CHECK: [[ADDR]] (1337 bytes) 55 // CHECK: SUMMARY: {{(Leak|Address)}}Sanitizer: 56 // CHECK-sanity: Value after LSan: [[ADDR]] 57