common_interface_defs.h

//===-- 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(void *pc, char *module_path,
                                             size_t module_path_len,
                                             void **pc_offset);

#ifdef __cplusplus
}  // extern "C"
#endif

#endif  // SANITIZER_COMMON_INTERFACE_DEFS_H