58 lines · cpp
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-return4// instrumentation stashes the argument to `PutPointerOnStaleStack` on the stack5// in order to conditionally call __asan_stack_malloc. This subverts our6// expectations for this test, where we assume the pointer is never stashed7// except at the bottom of the dead frame. Building at -O1 or greater solves8// this problem, because the compiler is smart enough to stash the argument in a9// callee-saved register for rematerialization instead.10// RUN: %clangxx_lsan -O1 %s -o %t11 12// RUN: %env_lsan_opts="report_objects=1:use_registers=0:use_stacks=1" not %run %t 2>&1 | FileCheck %s13// RUN: %env_lsan_opts="report_objects=1:use_registers=0:use_stacks=1:exitcode=0" %run %t 2>&1 | FileCheck --check-prefix=CHECK-sanity %s14//15// x86 passes parameters through stack that may lead to false negatives16// The same applies to s390x register save areas.17// UNSUPPORTED: i686,target={{(x86|powerpc64|arm|s390x).*}}18 19#include <stdio.h>20#include <stdlib.h>21#include "sanitizer_common/print_address.h"22 23void **pp;24 25// Put pointer far enough on the stack that LSan has space to run in without26// overwriting it.27// Hopefully the argument p will be passed on a register, saving us from false28// negatives.29__attribute__((noinline))30void *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 38int main() {39 PutPointerOnStaleStack(malloc(1337));40 return 0;41}42 43// This must run after LSan, to ensure LSan didn't overwrite the pointer before44// 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__attribute__((no_sanitize("hwaddress")))49void ConfirmPointerHasSurvived() {50 print_address("Value after LSan: ", 1, *pp);51}52// CHECK: Test alloc: [[ADDR:0x[0-9,a-f]+]]53// CHECK-sanity: Test alloc: [[ADDR:0x[0-9,a-f]+]]54// CHECK: LeakSanitizer: detected memory leaks55// CHECK: [[ADDR]] (1337 bytes)56// CHECK: SUMMARY: {{.*}}Sanitizer:57// CHECK-sanity: Value after LSan: [[ADDR]]58