| //===-- sanitizer_printf.cc -----------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is shared between AddressSanitizer and ThreadSanitizer. |
| // |
| // Internal printf function, used inside run-time libraries. |
| // We can't use libc printf because we intercept some of the functions used |
| // inside it. |
| //===----------------------------------------------------------------------===// |
| |
| |
| #include "sanitizer_common.h" |
| #include "sanitizer_flags.h" |
| #include "sanitizer_libc.h" |
| |
| #include <stdio.h> |
| #include <stdarg.h> |
| |
| #if SANITIZER_WINDOWS && defined(_MSC_VER) && _MSC_VER < 1800 && \ |
| !defined(va_copy) |
| # define va_copy(dst, src) ((dst) = (src)) |
| #endif |
| |
| namespace __sanitizer { |
| |
| StaticSpinMutex CommonSanitizerReportMutex; |
| |
| static int AppendChar(char **buff, const char *buff_end, char c) { |
| if (*buff < buff_end) { |
| **buff = c; |
| (*buff)++; |
| } |
| return 1; |
| } |
| |
| // Appends number in a given base to buffer. If its length is less than |
| // |minimal_num_length|, it is padded with leading zeroes or spaces, depending |
| // on the value of |pad_with_zero|. |
| static int AppendNumber(char **buff, const char *buff_end, u64 absolute_value, |
| u8 base, u8 minimal_num_length, bool pad_with_zero, |
| bool negative) { |
| uptr const kMaxLen = 30; |
| RAW_CHECK(base == 10 || base == 16); |
| RAW_CHECK(base == 10 || !negative); |
| RAW_CHECK(absolute_value || !negative); |
| RAW_CHECK(minimal_num_length < kMaxLen); |
| int result = 0; |
| if (negative && minimal_num_length) |
| --minimal_num_length; |
| if (negative && pad_with_zero) |
| result += AppendChar(buff, buff_end, '-'); |
| uptr num_buffer[kMaxLen]; |
| int pos = 0; |
| do { |
| RAW_CHECK_MSG((uptr)pos < kMaxLen, "AppendNumber buffer overflow"); |
| num_buffer[pos++] = absolute_value % base; |
| absolute_value /= base; |
| } while (absolute_value > 0); |
| if (pos < minimal_num_length) { |
| // Make sure compiler doesn't insert call to memset here. |
| internal_memset(&num_buffer[pos], 0, |
| sizeof(num_buffer[0]) * (minimal_num_length - pos)); |
| pos = minimal_num_length; |
| } |
| RAW_CHECK(pos > 0); |
| pos--; |
| for (; pos >= 0 && num_buffer[pos] == 0; pos--) { |
| char c = (pad_with_zero || pos == 0) ? '0' : ' '; |
| result += AppendChar(buff, buff_end, c); |
| } |
| if (negative && !pad_with_zero) result += AppendChar(buff, buff_end, '-'); |
| for (; pos >= 0; pos--) { |
| char digit = static_cast<char>(num_buffer[pos]); |
| result += AppendChar(buff, buff_end, (digit < 10) ? '0' + digit |
| : 'a' + digit - 10); |
| } |
| return result; |
| } |
| |
| static int AppendUnsigned(char **buff, const char *buff_end, u64 num, u8 base, |
| u8 minimal_num_length, bool pad_with_zero) { |
| return AppendNumber(buff, buff_end, num, base, minimal_num_length, |
| pad_with_zero, false /* negative */); |
| } |
| |
| static int AppendSignedDecimal(char **buff, const char *buff_end, s64 num, |
| u8 minimal_num_length, bool pad_with_zero) { |
| bool negative = (num < 0); |
| return AppendNumber(buff, buff_end, (u64)(negative ? -num : num), 10, |
| minimal_num_length, pad_with_zero, negative); |
| } |
| |
| static int AppendString(char **buff, const char *buff_end, int precision, |
| const char *s) { |
| if (s == 0) |
| s = "<null>"; |
| int result = 0; |
| for (; *s; s++) { |
| if (precision >= 0 && result >= precision) |
| break; |
| result += AppendChar(buff, buff_end, *s); |
| } |
| return result; |
| } |
| |
| static int AppendPointer(char **buff, const char *buff_end, u64 ptr_value) { |
| int result = 0; |
| result += AppendString(buff, buff_end, -1, "0x"); |
| result += AppendUnsigned(buff, buff_end, ptr_value, 16, |
| SANITIZER_POINTER_FORMAT_LENGTH, true); |
| return result; |
| } |
| |
| int VSNPrintf(char *buff, int buff_length, |
| const char *format, va_list args) { |
| static const char *kPrintfFormatsHelp = |
| "Supported Printf formats: %([0-9]*)?(z|ll)?{d,u,x}; %p; %(\\.\\*)?s; %c\n"; |
| RAW_CHECK(format); |
| RAW_CHECK(buff_length > 0); |
| const char *buff_end = &buff[buff_length - 1]; |
| const char *cur = format; |
| int result = 0; |
| for (; *cur; cur++) { |
| if (*cur != '%') { |
| result += AppendChar(&buff, buff_end, *cur); |
| continue; |
| } |
| cur++; |
| bool have_width = (*cur >= '0' && *cur <= '9'); |
| bool pad_with_zero = (*cur == '0'); |
| int width = 0; |
| if (have_width) { |
| while (*cur >= '0' && *cur <= '9') { |
| width = width * 10 + *cur++ - '0'; |
| } |
| } |
| bool have_precision = (cur[0] == '.' && cur[1] == '*'); |
| int precision = -1; |
| if (have_precision) { |
| cur += 2; |
| precision = va_arg(args, int); |
| } |
| bool have_z = (*cur == 'z'); |
| cur += have_z; |
| bool have_ll = !have_z && (cur[0] == 'l' && cur[1] == 'l'); |
| cur += have_ll * 2; |
| s64 dval; |
| u64 uval; |
| bool have_flags = have_width | have_z | have_ll; |
| // Only %s supports precision for now |
| CHECK(!(precision >= 0 && *cur != 's')); |
| switch (*cur) { |
| case 'd': { |
| dval = have_ll ? va_arg(args, s64) |
| : have_z ? va_arg(args, sptr) |
| : va_arg(args, int); |
| result += AppendSignedDecimal(&buff, buff_end, dval, width, |
| pad_with_zero); |
| break; |
| } |
| case 'u': |
| case 'x': { |
| uval = have_ll ? va_arg(args, u64) |
| : have_z ? va_arg(args, uptr) |
| : va_arg(args, unsigned); |
| result += AppendUnsigned(&buff, buff_end, uval, |
| (*cur == 'u') ? 10 : 16, width, pad_with_zero); |
| break; |
| } |
| case 'p': { |
| RAW_CHECK_MSG(!have_flags, kPrintfFormatsHelp); |
| result += AppendPointer(&buff, buff_end, va_arg(args, uptr)); |
| break; |
| } |
| case 's': { |
| RAW_CHECK_MSG(!have_flags, kPrintfFormatsHelp); |
| result += AppendString(&buff, buff_end, precision, va_arg(args, char*)); |
| break; |
| } |
| case 'c': { |
| RAW_CHECK_MSG(!have_flags, kPrintfFormatsHelp); |
| result += AppendChar(&buff, buff_end, va_arg(args, int)); |
| break; |
| } |
| case '%' : { |
| RAW_CHECK_MSG(!have_flags, kPrintfFormatsHelp); |
| result += AppendChar(&buff, buff_end, '%'); |
| break; |
| } |
| default: { |
| RAW_CHECK_MSG(false, kPrintfFormatsHelp); |
| } |
| } |
| } |
| RAW_CHECK(buff <= buff_end); |
| AppendChar(&buff, buff_end + 1, '\0'); |
| return result; |
| } |
| |
| static void (*PrintfAndReportCallback)(const char *); |
| void SetPrintfAndReportCallback(void (*callback)(const char *)) { |
| PrintfAndReportCallback = callback; |
| } |
| |
| // Can be overriden in frontend. |
| #if SANITIZER_SUPPORTS_WEAK_HOOKS |
| SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE |
| void OnPrint(const char *str) { |
| (void)str; |
| } |
| #elif defined(SANITIZER_GO) && defined(TSAN_EXTERNAL_HOOKS) |
| void OnPrint(const char *str); |
| #else |
| void OnPrint(const char *str) { |
| (void)str; |
| } |
| #endif |
| |
| static void CallPrintfAndReportCallback(const char *str) { |
| OnPrint(str); |
| if (PrintfAndReportCallback) |
| PrintfAndReportCallback(str); |
| } |
| |
| static void SharedPrintfCode(bool append_pid, const char *format, |
| va_list args) { |
| va_list args2; |
| va_copy(args2, args); |
| const int kLen = 16 * 1024; |
| // |local_buffer| is small enough not to overflow the stack and/or violate |
| // the stack limit enforced by TSan (-Wframe-larger-than=512). On the other |
| // hand, the bigger the buffer is, the more the chance the error report will |
| // fit into it. |
| char local_buffer[400]; |
| int needed_length; |
| char *buffer = local_buffer; |
| int buffer_size = ARRAY_SIZE(local_buffer); |
| // First try to print a message using a local buffer, and then fall back to |
| // mmaped buffer. |
| for (int use_mmap = 0; use_mmap < 2; use_mmap++) { |
| if (use_mmap) { |
| va_end(args); |
| va_copy(args, args2); |
| buffer = (char*)MmapOrDie(kLen, "Report"); |
| buffer_size = kLen; |
| } |
| needed_length = 0; |
| if (append_pid) { |
| int pid = internal_getpid(); |
| needed_length += internal_snprintf(buffer, buffer_size, "==%d==", pid); |
| if (needed_length >= buffer_size) { |
| // The pid doesn't fit into the current buffer. |
| if (!use_mmap) |
| continue; |
| RAW_CHECK_MSG(needed_length < kLen, "Buffer in Report is too short!\n"); |
| } |
| } |
| needed_length += VSNPrintf(buffer + needed_length, |
| buffer_size - needed_length, format, args); |
| if (needed_length >= buffer_size) { |
| // The message doesn't fit into the current buffer. |
| if (!use_mmap) |
| continue; |
| RAW_CHECK_MSG(needed_length < kLen, "Buffer in Report is too short!\n"); |
| } |
| // If the message fit into the buffer, print it and exit. |
| break; |
| } |
| RawWrite(buffer); |
| AndroidLogWrite(buffer); |
| CallPrintfAndReportCallback(buffer); |
| // If we had mapped any memory, clean up. |
| if (buffer != local_buffer) |
| UnmapOrDie((void *)buffer, buffer_size); |
| va_end(args2); |
| } |
| |
| FORMAT(1, 2) |
| void Printf(const char *format, ...) { |
| va_list args; |
| va_start(args, format); |
| SharedPrintfCode(false, format, args); |
| va_end(args); |
| } |
| |
| // Like Printf, but prints the current PID before the output string. |
| FORMAT(1, 2) |
| void Report(const char *format, ...) { |
| va_list args; |
| va_start(args, format); |
| SharedPrintfCode(true, format, args); |
| va_end(args); |
| } |
| |
| // Writes at most "length" symbols to "buffer" (including trailing '\0'). |
| // Returns the number of symbols that should have been written to buffer |
| // (not including trailing '\0'). Thus, the string is truncated |
| // iff return value is not less than "length". |
| FORMAT(3, 4) |
| int internal_snprintf(char *buffer, uptr length, const char *format, ...) { |
| va_list args; |
| va_start(args, format); |
| int needed_length = VSNPrintf(buffer, length, format, args); |
| va_end(args); |
| return needed_length; |
| } |
| |
| FORMAT(2, 3) |
| void InternalScopedString::append(const char *format, ...) { |
| CHECK_LT(length_, size()); |
| va_list args; |
| va_start(args, format); |
| VSNPrintf(data() + length_, size() - length_, format, args); |
| va_end(args); |
| length_ += internal_strlen(data() + length_); |
| CHECK_LT(length_, size()); |
| } |
| |
| } // namespace __sanitizer |
