text: //===-- sanitizer/common_interface_defs.h -----------------------*- C++ -*-===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  //
  // Common part of the public sanitizer interface.
  //===----------------------------------------------------------------------===//
  
  #ifndef SANITIZER_COMMON_INTERFACE_DEFS_H
  #define SANITIZER_COMMON_INTERFACE_DEFS_H
  
  #include <stddef.h>
  #include <stdint.h>
  
  // GCC does not understand __has_feature.
  #if !defined(__has_feature)
  #define __has_feature(x) 0
  #endif
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  // Arguments for __sanitizer_sandbox_on_notify() below.
  typedef struct {
    // Enable sandbox support in sanitizer coverage.
    int coverage_sandboxed;
    // File descriptor to write coverage data to. If -1 is passed, a file will
    // be pre-opened by __sanitizer_sandobx_on_notify(). This field has no
    // effect if coverage_sandboxed == 0.
    intptr_t coverage_fd;
    // If non-zero, split the coverage data into well-formed blocks. This is
    // useful when coverage_fd is a socket descriptor. Each block will contain
    // a header, allowing data from multiple processes to be sent over the same
    // socket.
    unsigned int coverage_max_block_size;
  } __sanitizer_sandbox_arguments;
  
  // Tell the tools to write their reports to "path.<pid>" instead of stderr.
  void __sanitizer_set_report_path(const char *path);
  // Tell the tools to write their reports to the provided file descriptor
  // (casted to void *).
  void __sanitizer_set_report_fd(void *fd);
  
  // Notify the tools that the sandbox is going to be turned on. The reserved
  // parameter will be used in the future to hold a structure with functions
  // that the tools may call to bypass the sandbox.
  void __sanitizer_sandbox_on_notify(__sanitizer_sandbox_arguments *args);
  
  // This function is called by the tool when it has just finished reporting
  // an error. 'error_summary' is a one-line string that summarizes
  // the error message. This function can be overridden by the client.
  void __sanitizer_report_error_summary(const char *error_summary);
  
  // Some of the sanitizers (for example ASan/TSan) could miss bugs that happen
  // in unaligned loads/stores. To find such bugs reliably, you need to replace
  // plain unaligned loads/stores with these calls.
  
  /// Loads a 16-bit unaligned value.
  ///
  /// \param p Pointer to unaligned memory.
  ///
  /// \returns Loaded value.
  uint16_t __sanitizer_unaligned_load16(const void *p);
  
  /// Loads a 32-bit unaligned value.
  ///
  /// \param p Pointer to unaligned memory.
  ///
  /// \returns Loaded value.
  uint32_t __sanitizer_unaligned_load32(const void *p);
  
  /// Loads a 64-bit unaligned value.
  ///
  /// \param p Pointer to unaligned memory.
  ///
  /// \returns Loaded value.
  uint64_t __sanitizer_unaligned_load64(const void *p);
  
  /// Stores a 16-bit unaligned value.
  ///
  /// \param p Pointer to unaligned memory.
  /// \param x 16-bit value to store.
  void __sanitizer_unaligned_store16(void *p, uint16_t x);
  
  /// Stores a 32-bit unaligned value.
  ///
  /// \param p Pointer to unaligned memory.
  /// \param x 32-bit value to store.
  void __sanitizer_unaligned_store32(void *p, uint32_t x);
  
  /// Stores a 64-bit unaligned value.
  ///
  /// \param p Pointer to unaligned memory.
  /// \param x 64-bit value to store.
  void __sanitizer_unaligned_store64(void *p, uint64_t x);
  
  // Returns 1 on the first call, then returns 0 thereafter.  Called by the tool
  // to ensure only one report is printed when multiple errors occur
  // simultaneously.
  int __sanitizer_acquire_crash_state();
  
  /// Annotates the current state of a contiguous container, such as
  /// <c>std::vector</c>, <c>std::string</c>, or similar.
  ///
  /// A contiguous container is a container that keeps all of its elements
  /// in a contiguous region of memory. The container owns the region of memory
  /// <c>[beg, end)</c>; the memory <c>[beg, mid)</c> is used to store the
  /// current elements, and the memory <c>[mid, end)</c> is reserved for future
  /// elements (<c>beg <= mid <= end</c>). For example, in
  /// <c>std::vector<> v</c>:
  ///
  /// \code
  ///   beg = &v[0];
  ///   end = beg + v.capacity() * sizeof(v[0]);
  ///   mid = beg + v.size()     * sizeof(v[0]);
  /// \endcode
  ///
  /// This annotation tells the Sanitizer tool about the current state of the
  /// container so that the tool can report errors when memory from
  /// <c>[mid, end)</c> is accessed. Insert this annotation into methods like
  /// <c>push_back()</c> or <c>pop_back()</c>. Supply the old and new values of
  /// <c>mid</c>(<c><i>old_mid</i></c> and <c><i>new_mid</i></c>). In the initial
  /// state <c>mid == end</c>, so that should be the final state when the
  /// container is destroyed or when the container reallocates the storage.
  ///
  /// For ASan, <c><i>beg</i></c> should be 8-aligned and <c><i>end</i></c>
  /// should be either 8-aligned or it should point to the end of a separate
  /// heap-, stack-, or global-allocated buffer. So the following example will
  /// not work:
  ///
  /// \code
  ///   int64_t x[2]; // 16 bytes, 8-aligned
  ///   char *beg = (char *)&x[0];
  ///   char *end = beg + 12; // Not 8-aligned, not the end of the buffer
  /// \endcode
  ///
  /// The following, however, will work:
  /// \code
  ///   int32_t x[3]; // 12 bytes, but 8-aligned under ASan.
  ///   char *beg = (char*)&x[0];
  ///   char *end = beg + 12; // Not 8-aligned, but is the end of the buffer
  /// \endcode
  ///
  /// \note  Use this function with caution and do not use for anything other
  /// than vector-like classes.
  ///
  /// \param beg Beginning of memory region.
  /// \param end End of memory region.
  /// \param old_mid Old middle of memory region.
  /// \param new_mid New middle of memory region.
  void __sanitizer_annotate_contiguous_container(const void *beg,
                                                 const void *end,
                                                 const void *old_mid,
                                                 const void *new_mid);
  
  /// Returns true if the contiguous container <c>[beg, end)</c> is properly
  /// poisoned.
  ///
  /// Proper poisoning could occur, for example, with
  /// <c>__sanitizer_annotate_contiguous_container</c>), that is, if
  /// <c>[beg, mid)</c> is addressable and <c>[mid, end)</c> is unaddressable.
  /// Full verification requires O (<c>end - beg</c>) time; this function tries
  /// to avoid such complexity by touching only parts of the container around
  /// <c><i>beg</i></c>, <c><i>mid</i></c>, and <c><i>end</i></c>.
  ///
  /// \param beg Beginning of memory region.
  /// \param mid Middle of memory region.
  /// \param end Old end of memory region.
  ///
  /// \returns True if the contiguous container <c>[beg, end)</c> is properly
  ///  poisoned.
  int __sanitizer_verify_contiguous_container(const void *beg, const void *mid,
                                              const void *end);
  
  /// Similar to <c>__sanitizer_verify_contiguous_container()</c> but also
  /// returns the address of the first improperly poisoned byte.
  ///
  /// Returns NULL if the area is poisoned properly.
  ///
  /// \param beg Beginning of memory region.
  /// \param mid Middle of memory region.
  /// \param end Old end of memory region.
  ///
  /// \returns The bad address or NULL.
  const void *__sanitizer_contiguous_container_find_bad_address(const void *beg,
                                                                const void *mid,
                                                                const void *end);
  
  /// Prints the stack trace leading to this call (useful for calling from the
  /// debugger).
  void __sanitizer_print_stack_trace(void);
  
  // Symbolizes the supplied 'pc' using the format string 'fmt'.
  // Outputs at most 'out_buf_size' bytes into 'out_buf'.
  // If 'out_buf' is not empty then output is zero or more non empty C strings
  // followed by single empty C string. Multiple strings can be returned if PC
  // corresponds to inlined function. Inlined frames are printed in the order
  // from "most-inlined" to the "least-inlined", so the last frame should be the
  // not inlined function.
  // Inlined frames can be removed with 'symbolize_inline_frames=0'.
  // The format syntax is described in
  // lib/sanitizer_common/sanitizer_stacktrace_printer.h.
  void __sanitizer_symbolize_pc(void *pc, const char *fmt, char *out_buf,
                                size_t out_buf_size);
  // Same as __sanitizer_symbolize_pc, but for data section (i.e. globals).
  void __sanitizer_symbolize_global(void *data_ptr, const char *fmt,
                                    char *out_buf, size_t out_buf_size);
  
  /// Sets the callback to be called immediately before death on error.
  ///
  /// Passing 0 will unset the callback.
  ///
  /// \param callback User-provided callback.
  void __sanitizer_set_death_callback(void (*callback)(void));
  
  
  // Interceptor hooks.
  // Whenever a libc function interceptor is called, it checks if the
  // corresponding weak hook is defined, and calls it if it is indeed defined.
  // The primary use-case is data-flow-guided fuzzing, where the fuzzer needs
  // to know what is being passed to libc functions (for example memcmp).
  // FIXME: implement more hooks.
  
  /// Interceptor hook for <c>memcmp()</c>.
  ///
  /// \param called_pc PC (program counter) address of the original call.
  /// \param s1 Pointer to block of memory.
  /// \param s2 Pointer to block of memory.
  /// \param n Number of bytes to compare.
  /// \param result Value returned by the intercepted function.
  void __sanitizer_weak_hook_memcmp(void *called_pc, const void *s1,
                                    const void *s2, size_t n, int result);
  
  /// Interceptor hook for <c>strncmp()</c>.
  ///
  /// \param called_pc PC (program counter) address of the original call.
  /// \param s1 Pointer to block of memory.
  /// \param s2 Pointer to block of memory.
  /// \param n Number of bytes to compare.
  /// \param result Value returned by the intercepted function.
  void __sanitizer_weak_hook_strncmp(void *called_pc, const char *s1,
                                    const char *s2, size_t n, int result);
  
  /// Interceptor hook for <c>strncasecmp()</c>.
  ///
  /// \param called_pc PC (program counter) address of the original call.
  /// \param s1 Pointer to block of memory.
  /// \param s2 Pointer to block of memory.
  /// \param n Number of bytes to compare.
  /// \param result Value returned by the intercepted function.
  void __sanitizer_weak_hook_strncasecmp(void *called_pc, const char *s1,
                                         const char *s2, size_t n, int result);
  
  /// Interceptor hook for <c>strcmp()</c>.
  ///
  /// \param called_pc PC (program counter) address of the original call.
  /// \param s1 Pointer to block of memory.
  /// \param s2 Pointer to block of memory.
  /// \param result Value returned by the intercepted function.
  void __sanitizer_weak_hook_strcmp(void *called_pc, const char *s1,
                                    const char *s2, int result);
  
  /// Interceptor hook for <c>strcasecmp()</c>.
  ///
  /// \param called_pc PC (program counter) address of the original call.
  /// \param s1 Pointer to block of memory.
  /// \param s2 Pointer to block of memory.
  /// \param result Value returned by the intercepted function.
  void __sanitizer_weak_hook_strcasecmp(void *called_pc, const char *s1,
                                        const char *s2, int result);
  
  /// Interceptor hook for <c>strstr()</c>.
  ///
  /// \param called_pc PC (program counter) address of the original call.
  /// \param s1 Pointer to block of memory.
  /// \param s2 Pointer to block of memory.
  /// \param result Value returned by the intercepted function.
  void __sanitizer_weak_hook_strstr(void *called_pc, const char *s1,
                                    const char *s2, char *result);
  
  void __sanitizer_weak_hook_strcasestr(void *called_pc, const char *s1,
                                        const char *s2, char *result);
  
  void __sanitizer_weak_hook_memmem(void *called_pc,
                                    const void *s1, size_t len1,
                                    const void *s2, size_t len2, void *result);
  
  // Prints stack traces for all live heap allocations ordered by total
  // allocation size until top_percent of total live heap is shown. top_percent
  // should be between 1 and 100. At most max_number_of_contexts contexts
  // (stack traces) are printed.
  // Experimental feature currently available only with ASan on Linux/x86_64.
  void __sanitizer_print_memory_profile(size_t top_percent,
                                        size_t max_number_of_contexts);
  
  /// Notify ASan that a fiber switch has started (required only if implementing
  /// your own fiber library).
  ///
  /// Before switching to a different stack, you must call
  /// <c>__sanitizer_start_switch_fiber()</c> with a pointer to the bottom of the
  /// destination stack and with its size. When code starts running on the new
  /// stack, it must call <c>__sanitizer_finish_switch_fiber()</c> to finalize
  /// the switch. The <c>__sanitizer_start_switch_fiber()</c> function takes a
  /// <c>void**</c> pointer argument to store the current fake stack if there is
  /// one (it is necessary when the runtime option
  /// <c>detect_stack_use_after_return</c> is enabled).
  ///
  /// When restoring a stack, this <c>void**</c> pointer must be given to the
  /// <c>__sanitizer_finish_switch_fiber()</c> function. In most cases, this
  /// pointer can be stored on the stack immediately before switching. When
  /// leaving a fiber definitely, NULL must be passed as the first argument to
  /// the <c>__sanitizer_start_switch_fiber()</c> function so that the fake stack
  /// is destroyed. If your program does not need stack use-after-return
  /// detection, you can always pass NULL to these two functions.
  ///
  /// \note The fake stack mechanism is disabled during fiber switch, so if a
  /// signal callback runs during the switch, it will not benefit from stack
  /// use-after-return detection.
  ///
  /// \param fake_stack_save [out] Fake stack save location.
  /// \param bottom Bottom address of stack.
  /// \param size Size of stack in bytes.
  void __sanitizer_start_switch_fiber(void **fake_stack_save,
                                      const void *bottom, size_t size);
  
  /// Notify ASan that a fiber switch has completed (required only if
  /// implementing your own fiber library).
  ///
  /// When code starts running on the new stack, it must call
  /// <c>__sanitizer_finish_switch_fiber()</c> to finalize
  /// the switch. For usage details, see the description of
  /// <c>__sanitizer_start_switch_fiber()</c>.
  ///
  /// \param fake_stack_save Fake stack save location.
  /// \param bottom_old [out] Bottom address of old stack.
  /// \param size_old [out] Size of old stack in bytes.
  void __sanitizer_finish_switch_fiber(void *fake_stack_save,
                                       const void **bottom_old,
                                       size_t *size_old);
  
  // Get full module name and calculate pc offset within it.
  // Returns 1 if pc belongs to some module, 0 if module was not found.
  int __sanitizer_get_module_and_offset_for_pc(uintptr_t pc, char *module_path,
                                               size_t module_path_len,
                                               void **pc_offset);
  
  #ifdef __cplusplus
  }  // extern "C"
  #endif
  
  #endif  // SANITIZER_COMMON_INTERFACE_DEFS_H
  