1  /*
       2   * Copyright (c) 2013-2021 The strace developers.
       3   *
       4   * SPDX-License-Identifier: LGPL-2.1-or-later
       5   */
       6  
       7  #ifndef STRACE_MMAP_CACHE_H
       8  # define STRACE_MMAP_CACHE_H
       9  
      10  /*
      11   * Keep a sorted array of cache entries,
      12   * so that we can binary search through it.
      13   */
      14  
      15  struct mmap_cache_t {
      16  	struct mmap_cache_entry_t *entry;
      17  	void (*free_fn)(struct tcb *, const char *caller);
      18  	unsigned int size;
      19  	unsigned int generation;
      20  };
      21  
      22  struct mmap_cache_entry_t {
      23  	/**
      24  	 * example entry:
      25  	 * 7fabbb09b000-7fabbb09f000 r-xp 00179000 fc:00 1180246 /lib/libc-2.11.1.so
      26  	 *
      27  	 * start_addr  is 0x7fabbb09b000
      28  	 * end_addr    is 0x7fabbb09f000
      29  	 * mmap_offset is 0x179000
      30  	 * protections is MMAP_CACHE_PROT_READABLE|MMAP_CACHE_PROT_EXECUTABLE
      31  	 * major       is 0xfc
      32  	 * minor       is 0x00
      33  	 * binary_filename is "/lib/libc-2.11.1.so"
      34  	 */
      35  	unsigned long start_addr;
      36  	unsigned long end_addr;
      37  	unsigned long mmap_offset;
      38  	unsigned char protections;
      39  	unsigned long major, minor;
      40  	char *binary_filename;
      41  };
      42  
      43  enum mmap_cache_protection {
      44  	MMAP_CACHE_PROT_READABLE   = 1 << 0,
      45  	MMAP_CACHE_PROT_WRITABLE   = 1 << 1,
      46  	MMAP_CACHE_PROT_EXECUTABLE = 1 << 2,
      47  	MMAP_CACHE_PROT_SHARED     = 1 << 3,
      48  };
      49  
      50  enum mmap_cache_rebuild_result {
      51  	MMAP_CACHE_REBUILD_NOCACHE,
      52  	MMAP_CACHE_REBUILD_READY,
      53  	MMAP_CACHE_REBUILD_RENEWED,
      54  };
      55  
      56  typedef bool (*mmap_cache_search_fn)(struct mmap_cache_entry_t *, void *);
      57  
      58  extern void
      59  mmap_cache_enable(void);
      60  
      61  extern enum mmap_cache_rebuild_result
      62  mmap_cache_rebuild_if_invalid(struct tcb *, const char *caller);
      63  
      64  extern struct mmap_cache_entry_t *
      65  mmap_cache_search(struct tcb *, unsigned long ip);
      66  
      67  extern struct mmap_cache_entry_t *
      68  mmap_cache_search_custom(struct tcb *, mmap_cache_search_fn, void *);
      69  
      70  #endif /* !STRACE_MMAP_CACHE_H */