1 #include <elf.h>
2 #include <poll.h>
3 #include <fcntl.h>
4 #include <signal.h>
5 #include <unistd.h>
6 #include "syscall.h"
7 #include "atomic.h"
8 #include "libc.h"
9 #include "pthread_impl.h"
10 #include <stdbool.h>
11
dummy(void)12 static void dummy(void) {}
13 weak_alias(dummy, _init);
14
15 extern weak hidden void (*const __init_array_start)(void), (*const __init_array_end)(void);
16 bool g_dl_inited = false;
17 #ifdef __LITEOS_DEBUG__
18 extern void parse_argv(int, char **);
19 #endif
dummy1(void * p)20 static void dummy1(void *p) {}
21 weak_alias(dummy1, __init_ssp);
22
23 #define AUX_CNT 38
24
25 #ifdef __GNUC__
26 __attribute__((__noinline__))
27 #endif
__init_libc(char ** envp,char * pn)28 void __init_libc(char **envp, char *pn)
29 {
30 size_t i, *auxv, aux[AUX_CNT] = { 0 };
31 __environ = envp;
32 for (i=0; envp[i]; i++);
33 libc.auxv = auxv = (void *)(envp+i+1);
34 for (i=0; auxv[i]; i+=2) if (auxv[i]<AUX_CNT) aux[auxv[i]] = auxv[i+1];
35 __hwcap = aux[AT_HWCAP];
36 if (aux[AT_SYSINFO]) __sysinfo = aux[AT_SYSINFO];
37 libc.page_size = aux[AT_PAGESZ];
38
39 if (!pn) pn = (void*)aux[AT_EXECFN];
40 if (!pn) pn = "";
41 __progname = __progname_full = pn;
42 for (i=0; pn[i]; i++) if (pn[i]=='/') __progname = pn+i+1;
43
44 __init_tls(aux);
45 __init_ssp((void *)aux[AT_RANDOM]);
46
47 if (aux[AT_UID]==aux[AT_EUID] && aux[AT_GID]==aux[AT_EGID]
48 && !aux[AT_SECURE]) return;
49
50 struct pollfd pfd[3] = { {.fd=0}, {.fd=1}, {.fd=2} };
51 int r =
52 #ifdef SYS_poll
53 __syscall(SYS_poll, pfd, 3, 0);
54 #else
55 __syscall(SYS_ppoll, pfd, 3, &(struct timespec){0}, 0, _NSIG/8);
56 #endif
57 if (r<0) a_crash();
58 for (i=0; i<3; i++) if (pfd[i].revents&POLLNVAL)
59 if (__sys_open("/dev/null", O_RDWR)<0)
60 a_crash();
61 libc.secure = 1;
62 }
63
libc_start_init(void)64 static void libc_start_init(void)
65 {
66 _init();
67 uintptr_t a = (uintptr_t)&__init_array_start;
68 for (; a<(uintptr_t)&__init_array_end; a+=sizeof(void(*)()))
69 (*(void (**)(void))a)();
70 }
71
72 weak_alias(libc_start_init, __libc_start_init);
73
74 typedef int lsm2_fn(int (*)(int,char **,char **), int, char **);
75 static lsm2_fn libc_start_main_stage2;
76
77 #ifdef ENABLE_HWASAN
78 weak void __hwasan_library_loaded(unsigned long int base, const Elf64_Phdr* phdr, int phnum);
79 weak void __hwasan_library_unloaded(unsigned long int base, const Elf64_Phdr* phdr, int phnum);
80 weak void __hwasan_init();
81 extern int __hwasan_check_enabled;
82 __attribute__((no_sanitize("hwaddress")))
83 #endif
__libc_start_main(int (* main)(int,char **,char **),int argc,char ** argv,void (* init_dummy)(),void (* fini_dummy)(),void (* ldso_dummy)())84 int __libc_start_main(int (*main)(int,char **,char **), int argc, char **argv,
85 void (*init_dummy)(), void(*fini_dummy)(), void(*ldso_dummy)())
86 {
87 char **envp = argv+argc+1;
88
89 #ifdef ENABLE_HWASAN
90 libc.load_hook = __hwasan_library_loaded;
91 libc.unload_hook = __hwasan_library_unloaded;
92 __hwasan_init();
93 __hwasan_check_enabled = 1;
94 #endif
95 /* External linkage, and explicit noinline attribute if available,
96 * are used to prevent the stack frame used during init from
97 * persisting for the entire process lifetime. */
98 __init_libc(envp, argv[0]);
99
100 /* Barrier against hoisting application code or anything using ssp
101 * or thread pointer prior to its initialization above. */
102 lsm2_fn *stage2 = libc_start_main_stage2;
103 __asm__ ( "" : "+r"(stage2) : : "memory" );
104 return stage2(main, argc, argv);
105 }
106
libc_start_main_stage2(int (* main)(int,char **,char **),int argc,char ** argv)107 static int libc_start_main_stage2(int (*main)(int,char **,char **), int argc, char **argv)
108 {
109 char **envp = argv+argc+1;
110 __libc_start_init();
111 #ifdef RESERVE_SIGNAL_STACK
112 pthread_reserve_signal_stack();
113 #endif
114 errno = 0;
115
116 #ifdef __LITEOS_A__
117 __sig_init();
118 #endif
119
120 #ifdef __LITEOS_DEBUG__
121 parse_argv(argc, argv);
122 #endif
123
124 #ifdef SANITIZER_OHOS
125 if (!load_asan_logger()) {
126 MUSL_LOGI("[musl_log] dlopen and dlsym libasan_logger failed!");
127 }
128 #endif
129
130 g_dl_inited = true;
131 /* Pass control to the application */
132 exit(main(argc, argv, envp));
133 return 0;
134 }
135