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