1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 * vim: set ts=8 sts=4 et sw=4 tw=99:
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #include "util/NativeStack.h"
8
9 #ifdef XP_WIN
10 #include "util/Windows.h"
11 #elif defined(XP_DARWIN) || defined(DARWIN) || defined(XP_UNIX)
12 #include <pthread.h>
13 #if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
14 #include <pthread_np.h>
15 #endif
16 #if defined(ANDROID) && !defined(__aarch64__)
17 #include <sys/types.h>
18 #include <unistd.h>
19 #endif
20 #else
21 #error "Unsupported platform"
22 #endif
23
24 #include "jsfriendapi.h"
25
26 #if defined(XP_WIN)
27
GetNativeStackBaseImpl()28 void* js::GetNativeStackBaseImpl() {
29 PNT_TIB pTib = reinterpret_cast<PNT_TIB>(NtCurrentTeb());
30 return static_cast<void*>(pTib->StackBase);
31 }
32
33 #elif defined(SOLARIS)
34
35 #include <ucontext.h>
36
37 JS_STATIC_ASSERT(JS_STACK_GROWTH_DIRECTION < 0);
38
GetNativeStackBaseImpl()39 void* js::GetNativeStackBaseImpl() {
40 stack_t st;
41 stack_getbounds(&st);
42 return static_cast<char*>(st.ss_sp) + st.ss_size;
43 }
44
45 #elif defined(AIX)
46
47 #include <ucontext.h>
48
49 JS_STATIC_ASSERT(JS_STACK_GROWTH_DIRECTION < 0);
50
GetNativeStackBaseImpl()51 void* js::GetNativeStackBaseImpl() {
52 ucontext_t context;
53 getcontext(&context);
54 return static_cast<char*>(context.uc_stack.ss_sp) + context.uc_stack.ss_size;
55 }
56
57 #else /* XP_UNIX */
58
GetNativeStackBaseImpl()59 void* js::GetNativeStackBaseImpl() {
60 pthread_t thread = pthread_self();
61 #if defined(XP_DARWIN) || defined(DARWIN)
62 return pthread_get_stackaddr_np(thread);
63
64 #else
65 pthread_attr_t sattr;
66 pthread_attr_init(&sattr);
67 #if defined(__OpenBSD__)
68 stack_t ss;
69 #elif defined(PTHREAD_NP_H) || defined(_PTHREAD_NP_H_) || defined(NETBSD)
70 /* e.g. on FreeBSD 4.8 or newer, neundorf@kde.org */
71 pthread_attr_get_np(thread, &sattr);
72 #else
73 /*
74 * FIXME: this function is non-portable;
75 * other POSIX systems may have different np alternatives
76 */
77 pthread_getattr_np(thread, &sattr);
78 #endif
79
80 void* stackBase = 0;
81 size_t stackSize = 0;
82 int rc;
83 #if defined(__OpenBSD__)
84 rc = pthread_stackseg_np(pthread_self(), &ss);
85 stackBase = (void*)((size_t)ss.ss_sp - ss.ss_size);
86 stackSize = ss.ss_size;
87 #elif defined(ANDROID) && !defined(__aarch64__)
88 if (gettid() == getpid()) {
89 // bionic's pthread_attr_getstack prior to API 21 doesn't tell the truth
90 // for the main thread (see bug 846670). So we scan /proc/self/maps to
91 // find the segment which contains the stack.
92 rc = -1;
93
94 // Put the string on the stack, otherwise there is the danger that it
95 // has not been decompressed by the the on-demand linker. Bug 1165460.
96 //
97 // The volatile keyword should stop the compiler from trying to omit
98 // the stack copy in the future (hopefully).
99 volatile char path[] = "/proc/self/maps";
100 FILE* fs = fopen((const char*)path, "r");
101
102 if (fs) {
103 char line[100];
104 unsigned long stackAddr = (unsigned long)&sattr;
105 while (fgets(line, sizeof(line), fs) != nullptr) {
106 unsigned long stackStart;
107 unsigned long stackEnd;
108 if (sscanf(line, "%lx-%lx ", &stackStart, &stackEnd) == 2 &&
109 stackAddr >= stackStart && stackAddr < stackEnd) {
110 stackBase = (void*)stackStart;
111 stackSize = stackEnd - stackStart;
112 rc = 0;
113 break;
114 }
115 }
116 fclose(fs);
117 }
118 } else
119 // For non main-threads pthread allocates the stack itself so it tells
120 // the truth.
121 rc = pthread_attr_getstack(&sattr, &stackBase, &stackSize);
122 #else
123 rc = pthread_attr_getstack(&sattr, &stackBase, &stackSize);
124 #endif
125 if (rc) MOZ_CRASH();
126 MOZ_ASSERT(stackBase);
127 pthread_attr_destroy(&sattr);
128
129 #if JS_STACK_GROWTH_DIRECTION > 0
130 return stackBase;
131 #else
132 return static_cast<char*>(stackBase) + stackSize;
133 #endif
134 #endif
135 }
136
137 #endif /* !XP_WIN */
138