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-rw-r--r--lib/sanitizer_common/sanitizer_printf.cpp358
1 files changed, 358 insertions, 0 deletions
diff --git a/lib/sanitizer_common/sanitizer_printf.cpp b/lib/sanitizer_common/sanitizer_printf.cpp
new file mode 100644
index 000000000000..a032787114bb
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_printf.cpp
@@ -0,0 +1,358 @@
+//===-- sanitizer_printf.cpp ----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// 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 {
+
+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, bool uppercase) {
+ 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]);
+ digit = (digit < 10) ? '0' + digit : (uppercase ? 'A' : 'a') + digit - 10;
+ result += AppendChar(buff, buff_end, digit);
+ }
+ return result;
+}
+
+static int AppendUnsigned(char **buff, const char *buff_end, u64 num, u8 base,
+ u8 minimal_num_length, bool pad_with_zero,
+ bool uppercase) {
+ return AppendNumber(buff, buff_end, num, base, minimal_num_length,
+ pad_with_zero, false /* negative */, uppercase);
+}
+
+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,
+ false /* uppercase */);
+}
+
+
+// Use the fact that explicitly requesting 0 width (%0s) results in UB and
+// interpret width == 0 as "no width requested":
+// width == 0 - no width requested
+// width < 0 - left-justify s within and pad it to -width chars, if necessary
+// width > 0 - right-justify s, not implemented yet
+static int AppendString(char **buff, const char *buff_end, int width,
+ int max_chars, const char *s) {
+ if (!s)
+ s = "<null>";
+ int result = 0;
+ for (; *s; s++) {
+ if (max_chars >= 0 && result >= max_chars)
+ break;
+ result += AppendChar(buff, buff_end, *s);
+ }
+ // Only the left justified strings are supported.
+ while (width < -result)
+ result += AppendChar(buff, buff_end, ' ');
+ return result;
+}
+
+static int AppendPointer(char **buff, const char *buff_end, u64 ptr_value) {
+ int result = 0;
+ result += AppendString(buff, buff_end, 0, -1, "0x");
+ result += AppendUnsigned(buff, buff_end, ptr_value, 16,
+ SANITIZER_POINTER_FORMAT_LENGTH,
+ true /* pad_with_zero */, false /* uppercase */);
+ 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,X}; %p; "
+ "%[-]([0-9]*)?(\\.\\*)?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 left_justified = *cur == '-';
+ if (left_justified)
+ 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;
+ const bool have_length = have_z || have_ll;
+ const bool have_flags = have_width || have_length;
+ // At the moment only %s supports precision and left-justification.
+ CHECK(!((precision >= 0 || left_justified) && *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':
+ case 'X': {
+ uval = have_ll ? va_arg(args, u64)
+ : have_z ? va_arg(args, uptr)
+ : va_arg(args, unsigned);
+ bool uppercase = (*cur == 'X');
+ result += AppendUnsigned(&buff, buff_end, uval, (*cur == 'u') ? 10 : 16,
+ width, pad_with_zero, uppercase);
+ 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_length, kPrintfFormatsHelp);
+ // Only left-justified width is supported.
+ CHECK(!have_width || left_justified);
+ result += AppendString(&buff, buff_end, left_justified ? -width : width,
+ 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_GO && defined(TSAN_EXTERNAL_HOOKS)
+// Implementation must be defined in frontend.
+extern "C" void __sanitizer_on_print(const char *str);
+#else
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_on_print, const char *str) {
+ (void)str;
+}
+#endif
+
+static void CallPrintfAndReportCallback(const char *str) {
+ __sanitizer_on_print(str);
+ if (PrintfAndReportCallback)
+ PrintfAndReportCallback(str);
+}
+
+static void NOINLINE SharedPrintfCodeNoBuffer(bool append_pid,
+ char *local_buffer,
+ int buffer_size,
+ const char *format,
+ va_list args) {
+ va_list args2;
+ va_copy(args2, args);
+ const int kLen = 16 * 1024;
+ int needed_length;
+ char *buffer = 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;
+ // Check that data fits into the current buffer.
+# define CHECK_NEEDED_LENGTH \
+ if (needed_length >= buffer_size) { \
+ if (!use_mmap) continue; \
+ RAW_CHECK_MSG(needed_length < kLen, \
+ "Buffer in Report is too short!\n"); \
+ }
+ // Fuchsia's logging infrastructure always keeps track of the logging
+ // process, thread, and timestamp, so never prepend such information.
+ if (!SANITIZER_FUCHSIA && append_pid) {
+ int pid = internal_getpid();
+ const char *exe_name = GetProcessName();
+ if (common_flags()->log_exe_name && exe_name) {
+ needed_length += internal_snprintf(buffer, buffer_size,
+ "==%s", exe_name);
+ CHECK_NEEDED_LENGTH
+ }
+ needed_length += internal_snprintf(
+ buffer + needed_length, buffer_size - needed_length, "==%d==", pid);
+ CHECK_NEEDED_LENGTH
+ }
+ needed_length += VSNPrintf(buffer + needed_length,
+ buffer_size - needed_length, format, args);
+ CHECK_NEEDED_LENGTH
+ // If the message fit into the buffer, print it and exit.
+ break;
+# undef CHECK_NEEDED_LENGTH
+ }
+ RawWrite(buffer);
+
+ // Remove color sequences from the message.
+ RemoveANSIEscapeSequencesFromString(buffer);
+ CallPrintfAndReportCallback(buffer);
+ LogMessageOnPrintf(buffer);
+
+ // If we had mapped any memory, clean up.
+ if (buffer != local_buffer)
+ UnmapOrDie((void *)buffer, buffer_size);
+ va_end(args2);
+}
+
+static void NOINLINE SharedPrintfCode(bool append_pid, const char *format,
+ va_list args) {
+ // |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];
+ SharedPrintfCodeNoBuffer(append_pid, local_buffer, ARRAY_SIZE(local_buffer),
+ format, args);
+}
+
+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