#include <poll.h>
#include <fcntl.h>
#include <signal.h>
+#include <unistd.h>
#include "syscall.h"
#include "atomic.h"
#include "libc.h"
-void __init_tls(size_t *);
-
static void dummy(void) {}
weak_alias(dummy, _init);
-__attribute__((__weak__, __visibility__("hidden")))
-extern void (*const __init_array_start)(void), (*const __init_array_end)(void);
+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 };
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];
- __sysinfo = aux[AT_SYSINFO];
+ if (aux[AT_SYSINFO]) __sysinfo = aux[AT_SYSINFO];
libc.page_size = aux[AT_PAGESZ];
if (!pn) pn = (void*)aux[AT_EXECFN];
&& !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();
_init();
uintptr_t a = (uintptr_t)&__init_array_start;
for (; a<(uintptr_t)&__init_array_end; a+=sizeof(void(*)()))
- (*(void (**)())a)();
+ (*(void (**)(void))a)();
}
weak_alias(libc_start_init, __libc_start_init);
-int __libc_start_main(int (*main)(int,char **,char **), int argc, char **argv)
+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,
+ void (*init_dummy)(), void(*fini_dummy)(), void(*ldso_dummy)())
{
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 */