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UserspaceEmulator+LibC: Have UE notice realloc() and update accounting

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When a mallocation is shrunk/grown without moving, UE needs to update
its precise metadata about the mallocation, since it tracks *exactly*
how many bytes were allocated, not just the malloc chunk size.
This commit is contained in:
Andreas Kling 2020-11-08 10:10:41 +01:00
parent a0e25b2d31
commit c4dd77a170
4 changed files with 41 additions and 1 deletions
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10
Libraries/LibC/malloc.cpp
View file

@ -57,6 +57,11 @@ ALWAYS_INLINE static void ue_notify_free(const void* ptr)
send_secret_data_to_userspace_emulator(2, (FlatPtr)ptr, 0);
}
ALWAYS_INLINE static void ue_notify_realloc(const void* ptr, size_t size)
{
send_secret_data_to_userspace_emulator(3, size, (FlatPtr)ptr);
}
static LibThread::Lock& malloc_lock()
{
static u32 lock_storage[sizeof(LibThread::Lock) / sizeof(u32)];
@ -470,8 +475,11 @@ void* realloc(void* ptr, size_t size)
LOCKER(malloc_lock());
auto existing_allocation_size = malloc_size(ptr);
if (size <= existing_allocation_size)
if (size <= existing_allocation_size) {
ue_notify_realloc(ptr, size);
return ptr;
}
auto* new_ptr = malloc(size);
if (new_ptr) {
memcpy(new_ptr, ptr, min(existing_allocation_size, size));