/* Initialization code run first thing by the ELF startup code. For i386/Hurd. Copyright (C) 1995,96,97,98,99,2000,01,02,03,04,05 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include <assert.h> #include <hurd.h> #include <stdio.h> #include <unistd.h> #include <string.h> #include <sysdep.h> #include <set-hooks.h> #include "hurdstartup.h" #include "hurdmalloc.h" /* XXX */ #include "../locale/localeinfo.h" #include <ldsodefs.h> #include <fpu_control.h> extern void __mach_init (void); extern void __init_misc (int, char **, char **); #ifdef USE_NONOPTION_FLAGS extern void __getopt_clean_environment (char **); #endif #ifndef SHARED extern void _dl_non_dynamic_init (void) internal_function; #endif extern void __libc_global_ctors (void); unsigned int __hurd_threadvar_max; unsigned long int __hurd_threadvar_stack_offset; unsigned long int __hurd_threadvar_stack_mask; #ifndef SHARED int __libc_enable_secure; #endif int __libc_multiple_libcs attribute_hidden = 1; extern int __libc_argc attribute_hidden; extern char **__libc_argv attribute_hidden; extern char **_dl_argv; extern void *(*_cthread_init_routine) (void) __attribute__ ((weak)); void (*_cthread_exit_routine) (int status) __attribute__ ((__noreturn__)); /* Things that want to be run before _hurd_init or much anything else. Importantly, these are called before anything tries to use malloc. */ DEFINE_HOOK (_hurd_preinit_hook, (void)); /* We call this once the Hurd magic is all set up and we are ready to be a Posixoid program. This does the same things the generic version does. */ static void posixland_init (int argc, char **argv, char **envp) { __libc_multiple_libcs = &_dl_starting_up && !_dl_starting_up; /* Make sure we don't initialize twice. */ if (!__libc_multiple_libcs) { /* Set the FPU control word to the proper default value. */ __setfpucw (__fpu_control); } /* Save the command-line arguments. */ __libc_argc = argc; __libc_argv = argv; __environ = envp; #ifndef SHARED _dl_non_dynamic_init (); #endif __init_misc (argc, argv, envp); #ifdef USE_NONOPTION_FLAGS /* This is a hack to make the special getopt in GNU libc working. */ __getopt_clean_environment (envp); #endif #if defined SHARED && !defined NO_CTORS_DTORS_SECTIONS __libc_global_ctors (); #endif } static void init1 (int argc, char *arg0, ...) { char **argv = &arg0; char **envp = &argv[argc + 1]; struct hurd_startup_data *d; #ifndef SHARED extern ElfW(Phdr) *_dl_phdr; extern size_t _dl_phnum; #endif while (*envp) ++envp; d = (void *) ++envp; /* If we are the bootstrap task started by the kernel, then after the environment pointers there is no Hurd data block; the argument strings start there. */ if ((void *) d == argv[0]) { #ifndef SHARED /* We may need to see our own phdrs, e.g. for TLS setup. Try the usual kludge to find the headers without help from the exec server. */ extern const void _start; const ElfW(Ehdr) *const ehdr = &_start; _dl_phdr = (ElfW(Phdr) *) ((const void *) ehdr + ehdr->e_phoff); _dl_phnum = ehdr->e_phnum; assert (ehdr->e_phentsize == sizeof (ElfW(Phdr))); #endif return; } #ifndef SHARED __libc_enable_secure = d->flags & EXEC_SECURE; _dl_phdr = (ElfW(Phdr) *) d->phdr; _dl_phnum = d->phdrsz / sizeof (ElfW(Phdr)); assert (d->phdrsz % sizeof (ElfW(Phdr)) == 0); #endif _hurd_init_dtable = d->dtable; _hurd_init_dtablesize = d->dtablesize; { /* Check if the stack we are now on is different from the one described by _hurd_stack_{base,size}. */ char dummy; const vm_address_t newsp = (vm_address_t) &dummy; if (d->stack_size != 0 && (newsp < d->stack_base || newsp - d->stack_base > d->stack_size)) /* The new stack pointer does not intersect with the stack the exec server set up for us, so free that stack. */ __vm_deallocate (__mach_task_self (), d->stack_base, d->stack_size); } if (d->portarray || d->intarray) /* Initialize library data structures, start signal processing, etc. */ _hurd_init (d->flags, argv, d->portarray, d->portarraysize, d->intarray, d->intarraysize); } static inline void init (int *data) { int argc = *data; char **argv = (void *) (data + 1); char **envp = &argv[argc + 1]; struct hurd_startup_data *d; unsigned long int threadvars[_HURD_THREADVAR_MAX]; /* Provide temporary storage for thread-specific variables on the startup stack so the cthreads initialization code can use them for malloc et al, or so we can use malloc below for the real threadvars array. */ memset (threadvars, 0, sizeof threadvars); threadvars[_HURD_THREADVAR_LOCALE] = (unsigned long int) &_nl_global_locale; __hurd_threadvar_stack_offset = (unsigned long int) threadvars; /* Since the cthreads initialization code uses malloc, and the malloc initialization code needs to get at the environment, make sure we can find it. We'll need to do this again later on since switching stacks changes the location where the environment is stored. */ __environ = envp; while (*envp) ++envp; d = (void *) ++envp; /* The user might have defined a value for this, to get more variables. Otherwise it will be zero on startup. We must make sure it is set properly before before cthreads initialization, so cthreads can know how much space to leave for thread variables. */ if (__hurd_threadvar_max < _HURD_THREADVAR_MAX) __hurd_threadvar_max = _HURD_THREADVAR_MAX; /* After possibly switching stacks, call `init1' (above) with the user code as the return address, and the argument data immediately above that on the stack. */ if (&_cthread_init_routine && _cthread_init_routine) { /* Initialize cthreads, which will allocate us a new stack to run on. */ int *newsp = (*_cthread_init_routine) (); struct hurd_startup_data *od; void switch_stacks (void); /* Copy per-thread variables from that temporary area onto the new cthread stack. */ memcpy (__hurd_threadvar_location_from_sp (0, newsp), threadvars, sizeof threadvars); /* Copy the argdata from the old stack to the new one. */ newsp = memcpy (newsp - ((char *) &d[1] - (char *) data), data, (char *) d - (char *) data); #ifdef SHARED /* And readjust the dynamic linker's idea of where the argument vector lives. */ assert (_dl_argv == argv); _dl_argv = (void *) (newsp + 1); #endif /* Set up the Hurd startup data block immediately following the argument and environment pointers on the new stack. */ od = ((void *) newsp + ((char *) d - (char *) data)); if ((void *) argv[0] == d) /* We were started up by the kernel with arguments on the stack. There is no Hurd startup data, so zero the block. */ memset (od, 0, sizeof *od); else /* Copy the Hurd startup data block to the new stack. */ *od = *d; /* Push the user code address on the top of the new stack. It will be the return address for `init1'; we will jump there with NEWSP as the stack pointer. */ *--newsp = data[-1]; ((void **) data)[-1] = switch_stacks; /* Force NEWSP into %ecx and &init1 into %eax, which are not restored by function return. */ asm volatile ("# a %0 c %1" : : "a" (newsp), "c" (&init1)); } else { /* We are not using cthreads, so we will have just a single allocated area for the per-thread variables of the main user thread. */ unsigned long int *array; unsigned int i; int usercode; void call_init1 (void); array = malloc (__hurd_threadvar_max * sizeof (unsigned long int)); if (array == NULL) __libc_fatal ("Can't allocate single-threaded thread variables."); /* Copy per-thread variables from the temporary array into the newly malloc'd space. */ memcpy (array, threadvars, sizeof threadvars); __hurd_threadvar_stack_offset = (unsigned long int) array; for (i = _HURD_THREADVAR_MAX; i < __hurd_threadvar_max; ++i) array[i] = 0; /* The argument data is just above the stack frame we will unwind by returning. Mutate our own return address to run the code below. */ usercode = data[-1]; data[-1] = (int) &call_init1; /* Force USERCODE into %eax and &init1 into %ecx, which are not restored by function return. */ asm volatile ("# a %0 c %1" : : "a" (usercode), "c" (&init1)); } } /* These bits of inline assembler used to be located inside `init'. However they were optimized away by gcc 2.95. */ /* The return address of `init' above, was redirected to here, so at this point our stack is unwound and callers' registers restored. Only %ecx and %eax are call-clobbered and thus still have the values we set just above. Fetch from there the new stack pointer we will run on, and jmp to the run-time address of `init1'; when it returns, it will run the user code with the argument data at the top of the stack. */ asm ("switch_stacks:\n" " movl %eax, %esp\n" " jmp *%ecx"); /* As in the stack-switching case, at this point our stack is unwound and callers' registers restored, and only %ecx and %eax communicate values from the lines above. In this case we have stashed in %eax the user code return address. Push it on the top of the stack so it acts as init1's return address, and then jump there. */ asm ("call_init1:\n" " push %eax\n" " jmp *%ecx\n"); /* Do the first essential initializations that must precede all else. */ static inline void first_init (void) { /* Initialize data structures so we can do RPCs. */ __mach_init (); RUN_HOOK (_hurd_preinit_hook, ()); } #ifdef SHARED /* This function is called specially by the dynamic linker to do early initialization of the shared C library before normal initializers expecting a Posixoid environment can run. It gets called with the stack set up just as the user will see it, so it can switch stacks. */ void _dl_init_first (void) { first_init (); init ((int *) __builtin_frame_address (0) + 2); } #endif #ifdef SHARED /* The regular posixland initialization is what goes into libc's normal initializer. */ /* NOTE! The linker notices the magical name `_init' and sets the DT_INIT pointer in the dynamic section based solely on that. It is convention for this function to be in the `.init' section, but the symbol name is the only thing that really matters!! */ strong_alias (posixland_init, _init); void __libc_init_first (int argc, char **argv, char **envp) { /* Everything was done in the shared library initializer, _init. */ } #else strong_alias (posixland_init, __libc_init_first); /* XXX This is all a crock and I am not happy with it. This poorly-named function is called by static-start.S, which should not exist at all. */ void _hurd_stack_setup (void) { intptr_t caller = (intptr_t) __builtin_return_address (0); void doinit (intptr_t *data) { /* This function gets called with the argument data at TOS. */ void doinit1 (void) { init ((int *) __builtin_frame_address (0) + 2); } /* Push the user return address after the argument data, and then jump to `doinit1' (above), so it is as if __libc_init_first's caller had called `doinit1' with the argument data already on the stack. */ *--data = caller; asm volatile ("movl %0, %%esp\n" /* Switch to new outermost stack. */ "movl $0, %%ebp\n" /* Clear outermost frame pointer. */ "jmp *%1" : : "r" (data), "r" (&doinit1) : "sp"); /* NOTREACHED */ } first_init (); _hurd_startup ((void **) __builtin_frame_address (0) + 2, &doinit); } #endif /* This function is defined here so that if this file ever gets into ld.so we will get a link error. Having this file silently included in ld.so causes disaster, because the _init definition above will cause ld.so to gain an init function, which is not a cool thing. */ void _dl_start (void) { abort (); }