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#include <elf.h>
#include <poll.h>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include "syscall.h"
#include "atomic.h"
#include "libc.h"
static void dummy(void) {}
weak_alias(dummy, _init);
extern weak hidden void (*const __init_array_start)(void), (*const __init_array_end)(void);
static void dummy1(void *p) {}
weak_alias(dummy1, __init_ssp);
#define AUX_CNT 38
#ifdef __GNUC__
__attribute__((__noinline__))
#endif
void __init_libc(char **envp, char *pn)
{
size_t i, *auxv, aux[AUX_CNT] = { 0 };
__environ = envp;
for (i=0; envp[i]; i++);
libc.auxv = auxv = (void *)(envp+i+1);
for (i=0; auxv[i]; i+=2) if (auxv[i]<AUX_CNT) aux[auxv[i]] = auxv[i+1];
__hwcap = aux[AT_HWCAP];
if (aux[AT_SYSINFO]) __sysinfo = aux[AT_SYSINFO];
libc.page_size = aux[AT_PAGESZ];
if (!pn) pn = (void*)aux[AT_EXECFN];
if (!pn) pn = "";
__progname = __progname_full = pn;
for (i=0; pn[i]; i++) if (pn[i]=='/') __progname = pn+i+1;
__init_tls(aux);
__init_ssp((void *)aux[AT_RANDOM]);
if (aux[AT_UID]==aux[AT_EUID] && aux[AT_GID]==aux[AT_EGID]
&& !aux[AT_SECURE]) return;
struct pollfd pfd[3] = { {.fd=0}, {.fd=1}, {.fd=2} };
int r =
#ifdef SYS_poll
__syscall(SYS_poll, pfd, 3, 0);
#else
__syscall(SYS_ppoll, pfd, 3, &(struct timespec){0}, 0, _NSIG/8);
#endif
if (r<0) a_crash();
for (i=0; i<3; i++) if (pfd[i].revents&POLLNVAL)
if (__sys_open("/dev/null", O_RDWR)<0)
a_crash();
libc.secure = 1;
}
static void libc_start_init(void)
{
_init();
uintptr_t a = (uintptr_t)&__init_array_start;
for (; a<(uintptr_t)&__init_array_end; a+=sizeof(void(*)()))
(*(void (**)(void))a)();
}
weak_alias(libc_start_init, __libc_start_init);
typedef int lsm2_fn(int (*)(int,char **,char **), int, char **);
static lsm2_fn libc_start_main_stage2;
int __libc_start_main(int (*main)(int,char **,char **), int argc, char **argv)
{
char **envp = argv+argc+1;
/* External linkage, and explicit noinline attribute if available,
* are used to prevent the stack frame used during init from
* persisting for the entire process lifetime. */
__init_libc(envp, argv[0]);
/* Barrier against hoisting application code or anything using ssp
* or thread pointer prior to its initialization above. */
lsm2_fn *stage2 = libc_start_main_stage2;
__asm__ ( "" : "+r"(stage2) : : "memory" );
return stage2(main, argc, argv);
}
static int libc_start_main_stage2(int (*main)(int,char **,char **), int argc, char **argv)
{
char **envp = argv+argc+1;
__libc_start_init();
/* Pass control to the application */
exit(main(argc, argv, envp));
return 0;
}
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