if (!PointerAndMemoryTagsMatch(user_old_p))
ReportInvalidFree(stack, reinterpret_cast<uptr>(user_old_p));
- void *old_p = GetAddressFromPointer(user_old_p);
- Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(old_p));
- uptr old_size = meta->requested_size;
- uptr actually_allocated_size = allocator.GetActuallyAllocatedSize(old_p);
- if (new_size <= actually_allocated_size) {
- // We are not reallocating here.
- // FIXME: update stack trace for the allocation?
- meta->requested_size = new_size;
- if (!atomic_load_relaxed(&hwasan_allocator_tagging_enabled))
- return user_old_p;
- if (flags()->retag_in_realloc) {
- HwasanThread *t = GetCurrentThread();
- return (void *)TagMemoryAligned(
- (uptr)old_p, new_size,
- t ? t->GenerateRandomTag() : kFallbackAllocTag);
- }
- if (new_size > old_size) {
- tag_t tag = GetTagFromPointer(reinterpret_cast<uptr>(user_old_p));
- TagMemoryAligned((uptr)old_p + old_size, new_size - old_size, tag);
- }
- return user_old_p;
- }
- uptr memcpy_size = Min(new_size, old_size);
void *new_p = HwasanAllocate(stack, new_size, alignment, false /*zeroise*/);
- if (new_p) {
- internal_memcpy(new_p, old_p, memcpy_size);
- HwasanDeallocate(stack, old_p);
+ if (user_old_p && new_p) {
+ void *untagged_ptr_old = GetAddressFromPointer(user_old_p);
+ Metadata *meta =
+ reinterpret_cast<Metadata *>(allocator.GetMetaData(untagged_ptr_old));
+ internal_memcpy(GetAddressFromPointer(new_p), untagged_ptr_old,
+ Min(new_size, static_cast<uptr>(meta->requested_size)));
+ HwasanDeallocate(stack, user_old_p);
}
- // FIXME: update t->heap_allocations or simplify HwasanReallocate.
return new_p;
}
HWASAN_FLAG(bool, tag_in_malloc, true, "")
HWASAN_FLAG(bool, tag_in_free, true, "")
-HWASAN_FLAG(bool, retag_in_realloc, true, "")
HWASAN_FLAG(bool, print_stats, false, "")
HWASAN_FLAG(bool, halt_on_error, true, "")
HWASAN_FLAG(bool, atexit, false, "")
--- /dev/null
+// Test basic realloc functionality.
+// RUN: %clang_hwasan %s -o %t
+// RUN: %run %t
+
+#include <stdlib.h>
+#include <assert.h>
+
+int main() {
+ char *x = (char*)realloc(nullptr, 4);
+ x[0] = 10;
+ x[1] = 20;
+ x[2] = 30;
+ x[3] = 40;
+ char *x1 = (char*)realloc(x, 5);
+ assert(x1 != x); // not necessary true for C,
+ // but true today for hwasan.
+ assert(x1[0] == 10 && x1[1] == 20 && x1[2] == 30 && x1[3] == 40);
+ x1[4] = 50;
+
+ char *x2 = (char*)realloc(x1, 6);
+ x2[5] = 60;
+ assert(x2 != x1);
+ assert(x2[0] == 10 && x2[1] == 20 && x2[2] == 30 && x2[3] == 40 &&
+ x2[4] == 50 && x2[5] == 60);
+
+ char *x3 = (char*)realloc(x2, 6);
+ assert(x3 != x2);
+ assert(x3[0] == 10 && x3[1] == 20 && x3[2] == 30 && x3[3] == 40 &&
+ x3[4] == 50 && x3[5] == 60);
+
+ char *x4 = (char*)realloc(x3, 5);
+ assert(x4 != x3);
+ assert(x4[0] == 10 && x4[1] == 20 && x4[2] == 30 && x4[3] == 40 &&
+ x4[4] == 50);
+}