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1//===-- allocator_interface.h ---------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// Public interface header for allocator used in sanitizers (ASan/TSan/MSan).10//===----------------------------------------------------------------------===//11#ifndef SANITIZER_ALLOCATOR_INTERFACE_H12#define SANITIZER_ALLOCATOR_INTERFACE_H13 14#include <sanitizer/common_interface_defs.h>15#include <stddef.h>16 17#ifdef __cplusplus18extern "C" {19#endif20/* Returns the estimated number of bytes that will be reserved by allocator21 for request of "size" bytes. If allocator can't allocate that much22 memory, returns the maximal possible allocation size, otherwise returns23 "size". */24size_t SANITIZER_CDECL __sanitizer_get_estimated_allocated_size(size_t size);25 26/* Returns true if p was returned by the allocator and27 is not yet freed. */28int SANITIZER_CDECL __sanitizer_get_ownership(const volatile void *p);29 30/* If a pointer lies within an allocation, it will return the start address31 of the allocation. Otherwise, it returns nullptr. */32const void *SANITIZER_CDECL __sanitizer_get_allocated_begin(const void *p);33 34/* Returns the number of bytes reserved for the pointer p.35 Requires (get_ownership(p) == true) or (p == 0). */36size_t SANITIZER_CDECL __sanitizer_get_allocated_size(const volatile void *p);37 38/* Returns the number of bytes reserved for the pointer p.39 Requires __sanitizer_get_allocated_begin(p) == p. */40size_t SANITIZER_CDECL41__sanitizer_get_allocated_size_fast(const volatile void *p);42 43/* Number of bytes, allocated and not yet freed by the application. */44size_t SANITIZER_CDECL __sanitizer_get_current_allocated_bytes(void);45 46/* Number of bytes, mmaped by the allocator to fulfill allocation requests.47 Generally, for request of X bytes, allocator can reserve and add to free48 lists a large number of chunks of size X to use them for future requests.49 All these chunks count toward the heap size. Currently, allocator never50 releases memory to OS (instead, it just puts freed chunks to free51 lists). */52size_t SANITIZER_CDECL __sanitizer_get_heap_size(void);53 54/* Number of bytes, mmaped by the allocator, which can be used to fulfill55 allocation requests. When a user program frees memory chunk, it can first56 fall into quarantine and will count toward __sanitizer_get_free_bytes()57 later. */58size_t SANITIZER_CDECL __sanitizer_get_free_bytes(void);59 60/* Number of bytes in unmapped pages, that are released to OS. Currently,61 always returns 0. */62size_t SANITIZER_CDECL __sanitizer_get_unmapped_bytes(void);63 64/* Malloc hooks that may be optionally provided by user.65 - __sanitizer_malloc_hook(ptr, size) is called immediately after allocation66 of "size" bytes, which returned "ptr".67 - __sanitizer_free_hook(ptr) is called immediately before deallocation of68 "ptr".69 - __sanitizer_ignore_free_hook(ptr) is called immediately before deallocation70 of "ptr", and if it returns a non-zero value, the deallocation of "ptr"71 will not take place. This allows software to make free a no-op until it72 calls free() again in the same pointer at a later time. Hint: read this as73 "ignore the free" rather than "ignore the hook".74*/75void SANITIZER_CDECL __sanitizer_malloc_hook(const volatile void *ptr,76 size_t size);77void SANITIZER_CDECL __sanitizer_free_hook(const volatile void *ptr);78int SANITIZER_CDECL __sanitizer_ignore_free_hook(const volatile void *ptr);79 80/* Installs a pair of hooks for malloc/free.81 Several (currently, 5) hook pairs may be installed, they are executed82 in the order they were installed and after calling83 __sanitizer_malloc_hook/__sanitizer_free_hook.84 Unlike __sanitizer_malloc_hook/__sanitizer_free_hook these hooks can be85 chained and do not rely on weak symbols working on the platform, but86 require __sanitizer_install_malloc_and_free_hooks to be called at startup87 and thus will not be called on malloc/free very early in the process.88 Returns the number of hooks currently installed or 0 on failure.89 Not thread-safe, should be called in the main thread before starting90 other threads.91*/92int SANITIZER_CDECL __sanitizer_install_malloc_and_free_hooks(93 void(SANITIZER_CDECL *malloc_hook)(const volatile void *, size_t),94 void(SANITIZER_CDECL *free_hook)(const volatile void *));95 96/* Drains allocator quarantines (calling thread's and global ones), returns97 freed memory back to OS and releases other non-essential internal allocator98 resources in attempt to reduce process RSS.99 Currently available with ASan only.100*/101void SANITIZER_CDECL __sanitizer_purge_allocator(void);102#ifdef __cplusplus103} // extern "C"104#endif105 106#endif107