/* Store the lowest stack address. This is done in ld.so if this is the code for the DSO. */ __libc_stack_end = stack_end;
# ifdef HAVE_AUX_VECTOR /* First process the auxiliary vector since we need to find the program header to locate an eventually present PT_TLS entry. */ # ifndef LIBC_START_MAIN_AUXVEC_ARG ElfW(auxv_t) *auxvec; { char **evp = ev; while (*evp++ != NULL) ; auxvec = (ElfW(auxv_t) *) evp; } # endif _dl_aux_init (auxvec); if (GL(dl_phdr) == NULL) # endif { /* Starting from binutils-2.23, the linker will define the magic symbol __ehdr_start to point to our own ELF header if it is visible in a segment that also includes the phdrs. So we can set up _dl_phdr and _dl_phnum even without any information from auxv. */
/* The stack guard goes into the TCB, so initialize it early. */ ARCH_SETUP_TLS ();
/* In some architectures, IREL{,A} relocations happen after TLS setup in order to let IFUNC resolvers benefit from TCB information, e.g. powerpc's hwcap and platform fields available in the TCB. */ ARCH_APPLY_IREL ();
/* Set up the stack checker's canary. */ uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random); # ifdef THREAD_SET_STACK_GUARD THREAD_SET_STACK_GUARD (stack_chk_guard); # else __stack_chk_guard = stack_chk_guard; # endif
# ifdef DL_SYSDEP_OSCHECK if (!__libc_multiple_libcs) { /* This needs to run to initiliaze _dl_osversion before TLS setup might check it. */ DL_SYSDEP_OSCHECK (__libc_fatal); } # endif
/* Initialize libpthread if linked in. */ if (__pthread_initialize_minimal != NULL) __pthread_initialize_minimal ();
/* Set up the pointer guard value. */ uintptr_t pointer_chk_guard = _dl_setup_pointer_guard (_dl_random, stack_chk_guard); # ifdef THREAD_SET_POINTER_GUARD THREAD_SET_POINTER_GUARD (pointer_chk_guard); # else __pointer_chk_guard_local = pointer_chk_guard; # endif
#endif/* !SHARED */
/* Register the destructor of the dynamic linker if there is any. */ if (__glibc_likely (rtld_fini != NULL)) __cxa_atexit ((void (*) (void *)) rtld_fini, NULL, NULL);
#ifndef SHARED /* Call the initializer of the libc. This is only needed here if we are compiling for the static library in which case we haven't run the constructors in `_dl_start_user'. */ __libc_init_first (argc, argv, __environ);
/* Register the destructor of the program, if any. */ if (fini) __cxa_atexit ((void (*) (void *)) fini, NULL, NULL);
/* Some security at this point. Prevent starting a SUID binary where the standard file descriptors are not opened. We have to do this only for statically linked applications since otherwise the dynamic loader did the work already. */ if (__builtin_expect (__libc_enable_secure, 0)) __libc_check_standard_fds (); #endif
/* Call the initializer of the program, if any. */ #ifdef SHARED if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0)) GLRO(dl_debug_printf) ("\ninitialize program: %s\n\n", argv[0]); #endif if (init) (*init) (argc, argv, __environ MAIN_AUXVEC_PARAM);
#ifdef SHARED /* Auditing checkpoint: we have a new object. */ if (__glibc_unlikely (GLRO(dl_naudit) > 0)) { structaudit_ifaces *afct = GLRO(dl_audit); structlink_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded; for (unsignedint cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->preinit != NULL) afct->preinit (&link_map_audit_state (head, cnt)->cookie);
#ifndef SHARED _dl_debug_initialize (0, LM_ID_BASE); #endif #ifdef HAVE_CLEANUP_JMP_BUF /* Memory for the cancellation buffer. */ structpthread_unwind_bufunwind_buf;
int not_first_call; not_first_call = setjmp ((struct __jmp_buf_tag *) unwind_buf.cancel_jmp_buf); if (__glibc_likely (! not_first_call)) { structpthread *self = THREAD_SELF;
/* Store old info. */ unwind_buf.priv.data.prev = THREAD_GETMEM (self, cleanup_jmp_buf); unwind_buf.priv.data.cleanup = THREAD_GETMEM (self, cleanup);
/* Store the new cleanup handler info. */ THREAD_SETMEM (self, cleanup_jmp_buf, &unwind_buf);
/* Run the program. */ result = main (argc, argv, __environ MAIN_AUXVEC_PARAM); } else { /* Remove the thread-local data. */ # ifdef SHARED PTHFCT_CALL (ptr__nptl_deallocate_tsd, ()); # else externvoid __nptl_deallocate_tsd (void) __attribute ((weak)); __nptl_deallocate_tsd (); # endif
/* One less thread. Decrement the counter. If it is zero we terminate the entire process. */ result = 0; # ifdef SHARED unsignedint *ptr = __libc_pthread_functions.ptr_nthreads; # ifdef PTR_DEMANGLE PTR_DEMANGLE (ptr); # endif # else externunsignedint __nptl_nthreads __attribute ((weak)); unsignedint *const ptr = &__nptl_nthreads; # endif
if (! atomic_decrement_and_test (ptr)) /* Not much left to do but to exit the thread, not the process. */ __exit_thread (); } #else /* Nothing fancy, just call the function. */ result = main (argc, argv, __environ MAIN_AUXVEC_PARAM); #endif
if (buffer->data == buffer->__space.__c) { /* Move buffer to the heap. No overflow is possible because buffer->length describes a small buffer on the stack. */ new_ptr = malloc (new_length); if (new_ptr == NULL) returnfalse; memcpy (new_ptr, buffer->__space.__c, buffer->length); } else { /* Buffer was already on the heap. Check for overflow. */ if (__glibc_likely (new_length >= buffer->length)) new_ptr = realloc (buffer->data, new_length); else { __set_errno (ENOMEM); new_ptr = NULL; }
if (__glibc_unlikely (new_ptr == NULL)) { /* Deallocate, but buffer must remain valid to free. */ free (buffer->data); scratch_buffer_init (buffer); returnfalse; } }
typedefstruct { void *tcb; /* Pointer to the TCB. Not necessarily the thread descriptor used by libpthread. */ dtv_t *dtv; void *self; /* Pointer to the thread descriptor. */ int multiple_threads; int gscope_flag; uintptr_t sysinfo; uintptr_t stack_guard; uintptr_t pointer_guard; unsignedlongint unused_vgetcpu_cache[2]; /* Bit 0: X86_FEATURE_1_IBT. Bit 1: X86_FEATURE_1_SHSTK. */ unsignedint feature_1; int __glibc_unused1; /* Reservation of some values for the TM ABI. */ void *__private_tm[4]; /* GCC split stack support. */ void *__private_ss; /* The lowest address of shadow stack, */ unsignedlonglongint ssp_base; /* Must be kept even if it is no longer used by glibc since programs, like AddressSanitizer, depend on the size of tcbhead_t. */ __128bits __glibc_unused2[8][4] __attribute__ ((aligned (32)));
