1 /* 2 * Copyright (c) 2013 The Chromium Authors. All rights reserved. 3 * Use of this source code is governed by a BSD-style license that can be 4 * found in the LICENSE file. 5 */ 6 7 #ifndef ERROR_HANDLING_ERROR_HANDLING_H_ 8 #define ERROR_HANDLING_ERROR_HANDLING_H_ 9 10 #include "error_handling/string_stream.h" 11 #include "sdk_util/macros.h" 12 13 EXTERN_C_BEGIN 14 15 struct NaClExceptionContext; 16 17 typedef void (*EHRawHandler)(struct NaClExceptionContext* context); 18 typedef void (*EHJsonHandler)(const char* str); 19 20 typedef struct { 21 uint32_t prog_ctr; 22 uint32_t frame_ptr; 23 uint32_t next_ptr; 24 } EHFrame; 25 26 27 /** Initialize error handling. 28 * 29 * Initializes the error handling to catch untrusted exceptions. The init 30 * functions will install an untrusted exception handler. 31 * 32 * The raw form will install the provided handler directly to the exception 33 * system. 34 * 35 * The json form will install a default handler which will walk the stack 36 * creating a valid JSON string which is passed to the provided handler. 37 * 38 * NOTE: Exception handling is enabled process wide. 39 * NOTE: Exception handling is not guaranteed to be available so it should 40 * not be considered an error if the request fails. 41 */ 42 void EHRequestExceptionsRaw(EHRawHandler callback); 43 void EHRequestExceptionsJson(EHJsonHandler callback); 44 45 46 /** Request an alternate signal handling stack for this thread. 47 * 48 * Specifies an alternate stack which will be used when this thread enters 49 * the exception handler. This is useful in cases when the threads original 50 * stack may have overflowed or may be too small to handler the exception. 51 * 52 * Returns the allocated stack or MAP_FAILED. 53 * 54 * NOTE: Unlike the handler, this is a per thread call. 55 * NOTE: If the allocation fails, the exception will still take place on the 56 * thread's original stack. 57 */ 58 void *EHRequestExceptionStackOnThread(size_t stack_size); 59 60 61 /** Determine if NaCl will forward exceptions. 62 * 63 * Returns non-zero if a hander has been installed and exceptions will 64 * be forwarded. 65 * 66 * NOTE: Exception handling is not guarenteed to be available so it should 67 * not be considered an error if the request fails. 68 */ 69 int EHHanderInstalled(); 70 71 72 /** Fill an exception frame from an exception context. */ 73 int EHGetTopFrame(sstream_t* ss, struct NaClExceptionContext* context, 74 EHFrame* frame); 75 76 77 /** Unwind the stack by one frame. 78 * 79 * Returns zero once it failes to unwind. 80 */ 81 int EHUnwindFrame(EHFrame* frame); 82 83 EXTERN_C_END 84 85 #endif // ERROR_HANDLING_ERROR_HANDLING_H_ 86 87
