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		3099a6bf2a
		
	
	
	
	
		
			
			This is a much more ergonomic option than getting a `VERIFY_NOT_REACHED()` failure at run-time. I encountered this issue with Clang, where sized deallocation is not the default due to ABI breakage concerns. Note that we can't simply just not declare these functions, because the C++ standard states: > If this function with size parameter is defined, the program shall > also define the version without the size parameter.
		
			
				
	
	
		
			99 lines
		
	
	
	
		
			4.2 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			99 lines
		
	
	
	
		
			4.2 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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|  *
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|  * SPDX-License-Identifier: BSD-2-Clause
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|  */
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| 
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| #pragma once
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| 
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| #include <AK/Types.h>
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| #include <Kernel/Debug.h>
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| #include <LibC/limits.h>
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| 
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| #define KMALLOC_SCRUB_BYTE 0xbb
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| #define KFREE_SCRUB_BYTE 0xaa
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| 
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| #define MAKE_ALIGNED_ALLOCATED(type, alignment)                                                                                   \
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| public:                                                                                                                           \
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|     [[nodiscard]] void* operator new(size_t)                                                                                      \
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|     {                                                                                                                             \
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|         void* ptr = kmalloc_aligned<alignment>(sizeof(type));                                                                     \
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|         VERIFY(ptr);                                                                                                              \
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|         return ptr;                                                                                                               \
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|     }                                                                                                                             \
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|     [[nodiscard]] void* operator new(size_t, const std::nothrow_t&) noexcept { return kmalloc_aligned<alignment>(sizeof(type)); } \
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|     void operator delete(void* ptr) noexcept { kfree_aligned(ptr); }                                                              \
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|                                                                                                                                   \
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| private:
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| 
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| // The C++ standard specifies that the nothrow allocation tag should live in the std namespace.
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| // Otherwise, `new (std::nothrow)` calls wouldn't get resolved.
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| namespace std {
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| struct nothrow_t {
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|     explicit nothrow_t() = default;
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| };
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| 
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| extern const nothrow_t nothrow;
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| 
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| enum class align_val_t : size_t {};
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| };
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| 
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| void kmalloc_init();
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| [[gnu::malloc, gnu::returns_nonnull, gnu::alloc_size(1)]] void* kmalloc_impl(size_t);
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| [[gnu::malloc, gnu::returns_nonnull, gnu::alloc_size(1)]] void* kmalloc_eternal(size_t);
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| 
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| void kfree(void*);
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| void kfree_sized(void*, size_t);
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| 
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| struct kmalloc_stats {
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|     size_t bytes_allocated;
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|     size_t bytes_free;
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|     size_t bytes_eternal;
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|     size_t kmalloc_call_count;
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|     size_t kfree_call_count;
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| };
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| void get_kmalloc_stats(kmalloc_stats&);
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| 
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| extern bool g_dump_kmalloc_stacks;
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| 
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| inline void* operator new(size_t, void* p) { return p; }
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| inline void* operator new[](size_t, void* p) { return p; }
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| 
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| [[nodiscard]] void* operator new(size_t size);
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| [[nodiscard]] void* operator new(size_t size, const std::nothrow_t&) noexcept;
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| [[nodiscard]] void* operator new(size_t size, std::align_val_t);
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| [[nodiscard]] void* operator new(size_t size, std::align_val_t, const std::nothrow_t&) noexcept;
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| 
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| void operator delete(void* ptr) noexcept DISALLOW("All deletes in the kernel should have a known size.");
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| void operator delete(void* ptr, size_t) noexcept;
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| void operator delete(void* ptr, std::align_val_t) noexcept DISALLOW("All deletes in the kernel should have a known size.");
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| void operator delete(void* ptr, size_t, std::align_val_t) noexcept;
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| 
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| [[nodiscard]] void* operator new[](size_t size);
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| [[nodiscard]] void* operator new[](size_t size, const std::nothrow_t&) noexcept;
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| 
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| void operator delete[](void* ptrs) noexcept DISALLOW("All deletes in the kernel should have a known size.");
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| void operator delete[](void* ptr, size_t) noexcept;
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| 
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| [[gnu::malloc, gnu::returns_nonnull, gnu::alloc_size(1)]] void* kmalloc(size_t);
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| 
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| template<size_t ALIGNMENT>
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| [[gnu::malloc, gnu::returns_nonnull, gnu::alloc_size(1)]] inline void* kmalloc_aligned(size_t size)
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| {
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|     static_assert(ALIGNMENT > sizeof(ptrdiff_t));
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|     static_assert(ALIGNMENT <= 4096);
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|     void* ptr = kmalloc(size + ALIGNMENT + sizeof(ptrdiff_t));
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|     size_t max_addr = (size_t)ptr + ALIGNMENT;
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|     void* aligned_ptr = (void*)(max_addr - (max_addr % ALIGNMENT));
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|     ((ptrdiff_t*)aligned_ptr)[-1] = (ptrdiff_t)((u8*)aligned_ptr - (u8*)ptr);
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|     return aligned_ptr;
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| }
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| 
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| inline void kfree_aligned(void* ptr)
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| {
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|     kfree((u8*)ptr - ((const ptrdiff_t*)ptr)[-1]);
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| }
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| 
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| size_t kmalloc_good_size(size_t);
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| 
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| void kmalloc_enable_expand();
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