1 //===-- sanitizer_file.cpp -----------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===---------------------------------------------------------------------===//
8 //
9 // This file is shared between AddressSanitizer and ThreadSanitizer
10 // run-time libraries.  It defines filesystem-related interfaces.  This
11 // is separate from sanitizer_common.cpp so that it's simpler to disable
12 // all the filesystem support code for a port that doesn't use it.
13 //
14 //===---------------------------------------------------------------------===//
15 
16 #include "sanitizer_platform.h"
17 
18 #if !SANITIZER_FUCHSIA
19 
20 #include "sanitizer_common.h"
21 #include "sanitizer_file.h"
22 
23 namespace __sanitizer {
24 
25 void CatastrophicErrorWrite(const char *buffer, uptr length) {
26   WriteToFile(kStderrFd, buffer, length);
27 }
28 
29 StaticSpinMutex report_file_mu;
30 ReportFile report_file = {&report_file_mu, kStderrFd, "", "", 0};
31 
32 void RawWrite(const char *buffer) {
33   report_file.Write(buffer, internal_strlen(buffer));
34 }
35 
36 void ReportFile::ReopenIfNecessary() {
37   mu->CheckLocked();
38   if (fd == kStdoutFd || fd == kStderrFd) return;
39 
40   uptr pid = internal_getpid();
41   // If in tracer, use the parent's file.
42   if (pid == stoptheworld_tracer_pid)
43     pid = stoptheworld_tracer_ppid;
44   if (fd != kInvalidFd) {
45     // If the report file is already opened by the current process,
46     // do nothing. Otherwise the report file was opened by the parent
47     // process, close it now.
48     if (fd_pid == pid)
49       return;
50     else
51       CloseFile(fd);
52   }
53 
54   const char *exe_name = GetProcessName();
55   if (common_flags()->log_exe_name && exe_name) {
56     internal_snprintf(full_path, kMaxPathLength, "%s.%s.%zu", path_prefix,
57                       exe_name, pid);
58   } else {
59     internal_snprintf(full_path, kMaxPathLength, "%s.%zu", path_prefix, pid);
60   }
61   fd = OpenFile(full_path, WrOnly);
62   if (fd == kInvalidFd) {
63     const char *ErrorMsgPrefix = "ERROR: Can't open file: ";
64     WriteToFile(kStderrFd, ErrorMsgPrefix, internal_strlen(ErrorMsgPrefix));
65     WriteToFile(kStderrFd, full_path, internal_strlen(full_path));
66     Die();
67   }
68   fd_pid = pid;
69 }
70 
71 void ReportFile::SetReportPath(const char *path) {
72   if (!path)
73     return;
74   uptr len = internal_strlen(path);
75   if (len > sizeof(path_prefix) - 100) {
76     Report("ERROR: Path is too long: %c%c%c%c%c%c%c%c...\n",
77            path[0], path[1], path[2], path[3],
78            path[4], path[5], path[6], path[7]);
79     Die();
80   }
81 
82   SpinMutexLock l(mu);
83   if (fd != kStdoutFd && fd != kStderrFd && fd != kInvalidFd)
84     CloseFile(fd);
85   fd = kInvalidFd;
86   if (internal_strcmp(path, "stdout") == 0) {
87     fd = kStdoutFd;
88   } else if (internal_strcmp(path, "stderr") == 0) {
89     fd = kStderrFd;
90   } else {
91     internal_snprintf(path_prefix, kMaxPathLength, "%s", path);
92   }
93 }
94 
95 bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
96                       uptr *read_len, uptr max_len, error_t *errno_p) {
97   *buff = nullptr;
98   *buff_size = 0;
99   *read_len = 0;
100   if (!max_len)
101     return true;
102   uptr PageSize = GetPageSizeCached();
103   uptr kMinFileLen = Min(PageSize, max_len);
104 
105   // The files we usually open are not seekable, so try different buffer sizes.
106   for (uptr size = kMinFileLen;; size = Min(size * 2, max_len)) {
107     UnmapOrDie(*buff, *buff_size);
108     *buff = (char*)MmapOrDie(size, __func__);
109     *buff_size = size;
110     fd_t fd = OpenFile(file_name, RdOnly, errno_p);
111     if (fd == kInvalidFd) {
112       UnmapOrDie(*buff, *buff_size);
113       return false;
114     }
115     *read_len = 0;
116     // Read up to one page at a time.
117     bool reached_eof = false;
118     while (*read_len < size) {
119       uptr just_read;
120       if (!ReadFromFile(fd, *buff + *read_len, size - *read_len, &just_read,
121                         errno_p)) {
122         UnmapOrDie(*buff, *buff_size);
123         CloseFile(fd);
124         return false;
125       }
126       *read_len += just_read;
127       if (just_read == 0 || *read_len == max_len) {
128         reached_eof = true;
129         break;
130       }
131     }
132     CloseFile(fd);
133     if (reached_eof)  // We've read the whole file.
134       break;
135   }
136   return true;
137 }
138 
139 bool ReadFileToVector(const char *file_name,
140                       InternalMmapVectorNoCtor<char> *buff, uptr max_len,
141                       error_t *errno_p) {
142   buff->clear();
143   if (!max_len)
144     return true;
145   uptr PageSize = GetPageSizeCached();
146   fd_t fd = OpenFile(file_name, RdOnly, errno_p);
147   if (fd == kInvalidFd)
148     return false;
149   uptr read_len = 0;
150   while (read_len < max_len) {
151     if (read_len >= buff->size())
152       buff->resize(Min(Max(PageSize, read_len * 2), max_len));
153     CHECK_LT(read_len, buff->size());
154     CHECK_LE(buff->size(), max_len);
155     uptr just_read;
156     if (!ReadFromFile(fd, buff->data() + read_len, buff->size() - read_len,
157                       &just_read, errno_p)) {
158       CloseFile(fd);
159       return false;
160     }
161     read_len += just_read;
162     if (!just_read)
163       break;
164   }
165   CloseFile(fd);
166   buff->resize(read_len);
167   return true;
168 }
169 
170 static const char kPathSeparator = SANITIZER_WINDOWS ? ';' : ':';
171 
172 char *FindPathToBinary(const char *name) {
173   if (FileExists(name)) {
174     return internal_strdup(name);
175   }
176 
177   const char *path = GetEnv("PATH");
178   if (!path)
179     return nullptr;
180   uptr name_len = internal_strlen(name);
181   InternalMmapVector<char> buffer(kMaxPathLength);
182   const char *beg = path;
183   while (true) {
184     const char *end = internal_strchrnul(beg, kPathSeparator);
185     uptr prefix_len = end - beg;
186     if (prefix_len + name_len + 2 <= kMaxPathLength) {
187       internal_memcpy(buffer.data(), beg, prefix_len);
188       buffer[prefix_len] = '/';
189       internal_memcpy(&buffer[prefix_len + 1], name, name_len);
190       buffer[prefix_len + 1 + name_len] = '\0';
191       if (FileExists(buffer.data()))
192         return internal_strdup(buffer.data());
193     }
194     if (*end == '\0') break;
195     beg = end + 1;
196   }
197   return nullptr;
198 }
199 
200 } // namespace __sanitizer
201 
202 using namespace __sanitizer;
203 
204 extern "C" {
205 void __sanitizer_set_report_path(const char *path) {
206   report_file.SetReportPath(path);
207 }
208 
209 void __sanitizer_set_report_fd(void *fd) {
210   report_file.fd = (fd_t)reinterpret_cast<uptr>(fd);
211   report_file.fd_pid = internal_getpid();
212 }
213 } // extern "C"
214 
215 #endif  // !SANITIZER_FUCHSIA
216