1 // Copyright 2014 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4
5 #include <limits.h>
6 #include <pthread.h>
7 #include <signal.h>
8 #include <string.h> /* for strerror */
9 #include <sys/param.h>
10 #include <unistd.h>
11 #include <stdlib.h>
12
13 #include "libcgo.h"
14 #include "libcgo_unix.h"
15
16 #include <TargetConditionals.h>
17
18 #if TARGET_OS_IPHONE
19 #include <CoreFoundation/CFBundle.h>
20 #include <CoreFoundation/CFString.h>
21 #endif
22
23 static void *threadentry(void*);
24 static void (*setg_gcc)(void*);
25
26 void
_cgo_sys_thread_start(ThreadStart * ts)27 _cgo_sys_thread_start(ThreadStart *ts)
28 {
29 pthread_attr_t attr;
30 sigset_t ign, oset;
31 pthread_t p;
32 size_t size;
33 int err;
34
35 //fprintf(stderr, "runtime/cgo: _cgo_sys_thread_start: fn=%p, g=%p\n", ts->fn, ts->g); // debug
36 sigfillset(&ign);
37 pthread_sigmask(SIG_SETMASK, &ign, &oset);
38
39 size = pthread_get_stacksize_np(pthread_self());
40 pthread_attr_init(&attr);
41 pthread_attr_setstacksize(&attr, size);
42 // Leave stacklo=0 and set stackhi=size; mstart will do the rest.
43 ts->g->stackhi = size;
44 err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);
45
46 pthread_sigmask(SIG_SETMASK, &oset, nil);
47
48 if (err != 0) {
49 fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
50 abort();
51 }
52 }
53
54 extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
55 static void*
threadentry(void * v)56 threadentry(void *v)
57 {
58 ThreadStart ts;
59
60 ts = *(ThreadStart*)v;
61 free(v);
62
63 #if TARGET_OS_IPHONE
64 darwin_arm_init_thread_exception_port();
65 #endif
66
67 crosscall1(ts.fn, setg_gcc, (void*)ts.g);
68 return nil;
69 }
70
71 #if TARGET_OS_IPHONE
72
73 // init_working_dir sets the current working directory to the app root.
74 // By default ios/arm64 processes start in "/".
75 static void
init_working_dir()76 init_working_dir()
77 {
78 CFBundleRef bundle = CFBundleGetMainBundle();
79 if (bundle == NULL) {
80 fprintf(stderr, "runtime/cgo: no main bundle\n");
81 return;
82 }
83 CFURLRef url_ref = CFBundleCopyResourceURL(bundle, CFSTR("Info"), CFSTR("plist"), NULL);
84 if (url_ref == NULL) {
85 // No Info.plist found. It can happen on Corellium virtual devices.
86 return;
87 }
88 CFStringRef url_str_ref = CFURLGetString(url_ref);
89 char buf[MAXPATHLEN];
90 Boolean res = CFStringGetCString(url_str_ref, buf, sizeof(buf), kCFStringEncodingUTF8);
91 CFRelease(url_ref);
92 if (!res) {
93 fprintf(stderr, "runtime/cgo: cannot get URL string\n");
94 return;
95 }
96
97 // url is of the form "file:///path/to/Info.plist".
98 // strip it down to the working directory "/path/to".
99 int url_len = strlen(buf);
100 if (url_len < sizeof("file://")+sizeof("/Info.plist")) {
101 fprintf(stderr, "runtime/cgo: bad URL: %s\n", buf);
102 return;
103 }
104 buf[url_len-sizeof("/Info.plist")+1] = 0;
105 char *dir = &buf[0] + sizeof("file://")-1;
106
107 if (chdir(dir) != 0) {
108 fprintf(stderr, "runtime/cgo: chdir(%s) failed\n", dir);
109 }
110
111 // The test harness in go_ios_exec passes the relative working directory
112 // in the GoExecWrapperWorkingDirectory property of the app bundle.
113 CFStringRef wd_ref = CFBundleGetValueForInfoDictionaryKey(bundle, CFSTR("GoExecWrapperWorkingDirectory"));
114 if (wd_ref != NULL) {
115 if (!CFStringGetCString(wd_ref, buf, sizeof(buf), kCFStringEncodingUTF8)) {
116 fprintf(stderr, "runtime/cgo: cannot get GoExecWrapperWorkingDirectory string\n");
117 return;
118 }
119 if (chdir(buf) != 0) {
120 fprintf(stderr, "runtime/cgo: chdir(%s) failed\n", buf);
121 }
122 }
123 }
124
125 #endif // TARGET_OS_IPHONE
126
127 void
x_cgo_init(G * g,void (* setg)(void *))128 x_cgo_init(G *g, void (*setg)(void*))
129 {
130 //fprintf(stderr, "x_cgo_init = %p\n", &x_cgo_init); // aid debugging in presence of ASLR
131 setg_gcc = setg;
132 _cgo_set_stacklo(g, NULL);
133
134 #if TARGET_OS_IPHONE
135 darwin_arm_init_mach_exception_handler();
136 darwin_arm_init_thread_exception_port();
137 init_working_dir();
138 #endif
139 }
140