1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // Platform-specific code for OpenBSD and NetBSD goes here. For the
6 // POSIX-compatible parts, the implementation is in platform-posix.cc.
7
8 #include <pthread.h>
9 #include <semaphore.h>
10 #include <signal.h>
11 #include <stdlib.h>
12 #include <sys/resource.h>
13 #include <sys/syscall.h>
14 #include <sys/time.h>
15 #include <sys/types.h>
16
17 #include <errno.h>
18 #include <fcntl.h> // open
19 #include <stdarg.h>
20 #include <strings.h> // index
21 #include <sys/mman.h> // mmap & munmap
22 #include <sys/stat.h> // open
23 #include <unistd.h> // sysconf
24
25 #include <cmath>
26
27 #undef MAP_TYPE
28
29 #include "src/base/macros.h"
30 #include "src/base/platform/platform-posix-time.h"
31 #include "src/base/platform/platform-posix.h"
32 #include "src/base/platform/platform.h"
33
34 namespace v8 {
35 namespace base {
36
CreateTimezoneCache()37 TimezoneCache* OS::CreateTimezoneCache() {
38 return new PosixDefaultTimezoneCache();
39 }
40
GetSharedLibraryAddresses()41 std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
42 std::vector<SharedLibraryAddress> result;
43 // This function assumes that the layout of the file is as follows:
44 // hex_start_addr-hex_end_addr rwxp <unused data> [binary_file_name]
45 // If we encounter an unexpected situation we abort scanning further entries.
46 FILE* fp = fopen("/proc/self/maps", "r");
47 if (fp == nullptr) return result;
48
49 // Allocate enough room to be able to store a full file name.
50 const int kLibNameLen = FILENAME_MAX + 1;
51 char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen));
52
53 // This loop will terminate once the scanning hits an EOF.
54 while (true) {
55 uintptr_t start, end;
56 char attr_r, attr_w, attr_x, attr_p;
57 // Parse the addresses and permission bits at the beginning of the line.
58 if (fscanf(fp, "%" V8PRIxPTR "-%" V8PRIxPTR, &start, &end) != 2) break;
59 if (fscanf(fp, " %c%c%c%c", &attr_r, &attr_w, &attr_x, &attr_p) != 4) break;
60
61 int c;
62 if (attr_r == 'r' && attr_w != 'w' && attr_x == 'x') {
63 // Found a read-only executable entry. Skip characters until we reach
64 // the beginning of the filename or the end of the line.
65 do {
66 c = getc(fp);
67 } while ((c != EOF) && (c != '\n') && (c != '/'));
68 if (c == EOF) break; // EOF: Was unexpected, just exit.
69
70 // Process the filename if found.
71 if (c == '/') {
72 ungetc(c, fp); // Push the '/' back into the stream to be read below.
73
74 // Read to the end of the line. Exit if the read fails.
75 if (fgets(lib_name, kLibNameLen, fp) == nullptr) break;
76
77 // Drop the newline character read by fgets. We do not need to check
78 // for a zero-length string because we know that we at least read the
79 // '/' character.
80 lib_name[strlen(lib_name) - 1] = '\0';
81 } else {
82 // No library name found, just record the raw address range.
83 snprintf(lib_name, kLibNameLen,
84 "%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end);
85 }
86 result.push_back(SharedLibraryAddress(lib_name, start, end));
87 } else {
88 // Entry not describing executable data. Skip to end of line to set up
89 // reading the next entry.
90 do {
91 c = getc(fp);
92 } while ((c != EOF) && (c != '\n'));
93 if (c == EOF) break;
94 }
95 }
96 free(lib_name);
97 fclose(fp);
98 return result;
99 }
100
SignalCodeMovingGC()101 void OS::SignalCodeMovingGC() {
102 // Support for ll_prof.py.
103 //
104 // The Linux profiler built into the kernel logs all mmap's with
105 // PROT_EXEC so that analysis tools can properly attribute ticks. We
106 // do a mmap with a name known by ll_prof.py and immediately munmap
107 // it. This injects a GC marker into the stream of events generated
108 // by the kernel and allows us to synchronize V8 code log and the
109 // kernel log.
110 long size = sysconf(_SC_PAGESIZE); // NOLINT: type more fit than uint64_t
111 FILE* f = fopen(OS::GetGCFakeMMapFile(), "w+");
112 if (f == nullptr) {
113 OS::PrintError("Failed to open %s\n", OS::GetGCFakeMMapFile());
114 OS::Abort();
115 }
116 void* addr =
117 mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_PRIVATE, fileno(f), 0);
118 DCHECK(addr != MAP_FAILED);
119 OS::Free(addr, size);
120 fclose(f);
121 }
122
AdjustSchedulingParams()123 void OS::AdjustSchedulingParams() {}
124
GetFreeMemoryRangesWithin(OS::Address boundary_start,OS::Address boundary_end,size_t minimum_size,size_t alignment)125 std::vector<OS::MemoryRange> OS::GetFreeMemoryRangesWithin(
126 OS::Address boundary_start, OS::Address boundary_end, size_t minimum_size,
127 size_t alignment) {
128 return {};
129 }
130
131 } // namespace base
132 } // namespace v8
133