mach_vm_allocate.c
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// Test that mach_vm_[de]allocate resets shadow memory status.
//
// RUN: %clang_tsan %s -o %t
// RUN: %run %t 2>&1 | FileCheck %s --implicit-check-not='ThreadSanitizer'
#include <mach/mach.h>
#include <mach/mach_vm.h>
#include <pthread.h>
#include <assert.h>
#include <stdio.h>
#include "../test.h"
const mach_vm_size_t alloc_size = sizeof(int);
static int *global_ptr;
static int *alloc() {
mach_vm_address_t addr;
kern_return_t kr =
mach_vm_allocate(mach_task_self(), &addr, alloc_size, VM_FLAGS_ANYWHERE);
assert(kr == KERN_SUCCESS);
return (int *)addr;
}
static void alloc_fixed(int *ptr) {
mach_vm_address_t addr = (mach_vm_address_t)ptr;
// Re-allocation via VM_FLAGS_FIXED sporadically fails.
kern_return_t kr =
mach_vm_allocate(mach_task_self(), &addr, alloc_size, VM_FLAGS_FIXED);
if (kr != KERN_SUCCESS)
global_ptr = NULL;
}
static void dealloc(int *ptr) {
kern_return_t kr =
mach_vm_deallocate(mach_task_self(), (mach_vm_address_t)ptr, alloc_size);
assert(kr == KERN_SUCCESS);
}
static void *Thread(void *arg) {
*global_ptr = 7; // Assignment 1
// We want to test that TSan does not report a race between the two
// assignments to *global_ptr when the underlying memory is re-allocated
// between assignments. The calls to the API itself are racy though, so ignore
// them.
AnnotateIgnoreWritesBegin(__FILE__, __LINE__);
dealloc(global_ptr);
alloc_fixed(global_ptr);
AnnotateIgnoreWritesEnd(__FILE__, __LINE__);
barrier_wait(&barrier);
return NULL;
}
static bool try_realloc_on_same_address() {
barrier_init(&barrier, 2);
global_ptr = alloc();
pthread_t t;
pthread_create(&t, NULL, Thread, NULL);
barrier_wait(&barrier);
if (global_ptr)
*global_ptr = 8; // Assignment 2
pthread_join(t, NULL);
dealloc(global_ptr);
return global_ptr != NULL;
}
int main(int argc, const char *argv[]) {
bool success;
for (int i = 0; i < 10; i++) {
success = try_realloc_on_same_address();
if (success) break;
}
if (!success)
fprintf(stderr, "Unable to set up testing condition; silently pass test\n");
printf("Done.\n");
return 0;
}
// CHECK: Done.