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Diffstat (limited to 'sysdeps/mach/hurd/start.c')
| -rw-r--r-- | sysdeps/mach/hurd/start.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/start.c b/sysdeps/mach/hurd/start.c new file mode 100644 index 0000000000..91be7eaefe --- /dev/null +++ b/sysdeps/mach/hurd/start.c @@ -0,0 +1,316 @@ +/* Copyright (C) 1991, 1992, 1993, 1994, 1995 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <errno.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <hurd.h> +#include <hurd/exec.h> +#include <sysdep.h> +#include <hurd/threadvar.h> +#include "set-hooks.h" +#include "hurdmalloc.h" /* XXX */ + +/* The first piece of initialized data. */ +int __data_start = 0; +weak_alias (__data_start, data_start) + +mach_port_t *_hurd_init_dtable; +mach_msg_type_number_t _hurd_init_dtablesize; + +unsigned int __hurd_threadvar_max; +unsigned long int __hurd_threadvar_stack_mask; +unsigned long int __hurd_threadvar_stack_offset; + +/* These are set up by _hurdsig_init. */ +unsigned long int __hurd_sigthread_stack_base; +unsigned long int __hurd_sigthread_stack_end; +unsigned long int *__hurd_sigthread_variables; + +vm_address_t _hurd_stack_base; +vm_size_t _hurd_stack_size; + +char **__environ; +weak_alias (__environ, environ) + +/* 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)); + +extern void __mach_init (void); +extern void __libc_init (int argc, char **argv, char **envp); +extern int main (int argc, char **argv, char **envp); + +void *(*_cthread_init_routine) (void); /* Returns new SP to use. */ +void (*_cthread_exit_routine) (int status) __attribute__ ((__noreturn__)); + +int _hurd_split_args (char *, size_t, char **); + +/* These communicate values from _start to start1, + where we cannot use the stack for anything. */ +static char *args, *env; +static mach_port_t *portarray; +static int *intarray; +static mach_msg_type_number_t argslen, envlen, portarraysize, intarraysize; +static int flags; +static char **argv, **envp; +static int argc; + + +static void start1 (void) __attribute__ ((__noreturn__)); + + +/* Entry point. This is the first thing in the text segment. + + The exec server started the initial thread in our task with this spot the + PC, and a stack that is presumably big enough. We do basic Mach + initialization so mig-generated stubs work, and then do an exec_startup + RPC on our bootstrap port, to which the exec server responds with the + information passed in the exec call, as well as our original bootstrap + port, and the base address and size of the preallocated stack. + + If using cthreads, we are given a new stack by cthreads initialization and + deallocate the stack set up by the exec server. On the new stack we call + `start1' (above) to do the rest of the startup work. Since the stack may + disappear out from under us in a machine-dependent way, we use a pile of + static variables to communicate the information from exec_startup to start1. + This is unfortunate but preferable to machine-dependent frobnication to copy + the state from the old stack to the new one. */ + +#ifndef START_ARGS +#define START_ARGS void +#endif +#ifdef START_MACHDEP +START_MACHDEP +#define _start _start0 +#endif + +void +_start (START_ARGS) +{ + error_t err; + mach_port_t in_bootstrap; + + /* Basic Mach initialization, must be done before RPCs can be done. */ + __mach_init (); + + /* Run things that want to do initialization as soon as possible. We do + this before exec_startup so that no out of line data arrives and + clutters up the address space before brk initialization. */ + + RUN_HOOK (_hurd_preinit_hook, ()); + + if (err = __task_get_special_port (__mach_task_self (), TASK_BOOTSTRAP_PORT, + &in_bootstrap)) + LOSE; + + if (in_bootstrap != MACH_PORT_NULL) + { + /* Call the exec server on our bootstrap port and + get all our standard information from it. */ + + argslen = envlen = 0; + _hurd_init_dtablesize = portarraysize = intarraysize = 0; + + err = __exec_startup (in_bootstrap, + &_hurd_stack_base, &_hurd_stack_size, + &flags, + &args, &argslen, &env, &envlen, + &_hurd_init_dtable, &_hurd_init_dtablesize, + &portarray, &portarraysize, + &intarray, &intarraysize); + __mach_port_deallocate (__mach_task_self (), in_bootstrap); + } + + if (err || in_bootstrap == MACH_PORT_NULL) + { + /* Either we have no bootstrap port, or the RPC to the exec server + failed. Try to snarf the args in the canonical Mach way. + Hopefully either they will be on the stack as expected, or the + stack will be zeros so we don't crash. Set all our other + variables to have empty information. */ + + /* SNARF_ARGS (ARGC, ARGV, ENVP) snarfs the arguments and environment + from the stack, assuming they were put there by the microkernel. */ + SNARF_ARGS (argc, argv, envp); + + flags = 0; + args = env = NULL; + argslen = envlen = 0; + _hurd_init_dtable = NULL; + _hurd_init_dtablesize = 0; + portarray = NULL; + portarraysize = 0; + intarray = NULL; + intarraysize = 0; + } + else + argv = envp = NULL; + + + /* 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; + + /* Do cthreads initialization and switch to the cthread stack. */ + + if (_cthread_init_routine != NULL) + CALL_WITH_SP (start1, (*_cthread_init_routine) ()); + else + start1 (); + + /* Should never get here. */ + LOSE; +} + + +static void +start1 (void) +{ + register int envc = 0; + + { + /* 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 (_hurd_stack_size != 0 && (newsp < _hurd_stack_base || + newsp - _hurd_stack_base > _hurd_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 (), + _hurd_stack_base, _hurd_stack_size); + } + + if (__hurd_threadvar_stack_mask == 0) + { + /* 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 i; + __hurd_threadvar_stack_offset + = (unsigned long int) malloc (__hurd_threadvar_max * + sizeof (unsigned long int)); + if (__hurd_threadvar_stack_offset == 0) + __libc_fatal ("Can't allocate single-threaded per-thread variables."); + for (i = 0; i < __hurd_threadvar_max; ++i) + ((unsigned long int *) __hurd_threadvar_stack_offset)[i] = 0; + } + + + /* Turn the block of null-separated strings we were passed for the + arguments and environment into vectors of pointers to strings. */ + + if (! argv) + { + if (args) + /* Count up the arguments so we can allocate ARGV. */ + argc = _hurd_split_args (args, argslen, NULL); + if (! args || argc == 0) + { + /* No arguments passed; set argv to { NULL }. */ + argc = 0; + args = NULL; + argv = (char **) &args; + } + } + + if (! envp) + { + if (env) + /* Count up the environment variables so we can allocate ENVP. */ + envc = _hurd_split_args (env, envlen, NULL); + if (! env || envc == 0) + { + /* No environment passed; set __environ to { NULL }. */ + env = NULL; + envp = (char **) &env; + } + } + + if (! argv) + { + /* There were some arguments. + Allocate space for the vectors of pointers and fill them in. */ + argv = __alloca ((argc + 1) * sizeof (char *)); + _hurd_split_args (args, argslen, argv); + } + + if (! envp) + { + /* There was some environment. + Allocate space for the vectors of pointers and fill them in. */ + envp = __alloca ((envc + 1) * sizeof (char *)); + _hurd_split_args (env, envlen, envp); + } + + __environ = envp; + + if (portarray || intarray) + /* Initialize library data structures, start signal processing, etc. */ + _hurd_init (flags, argv, portarray, portarraysize, intarray, intarraysize); + + /* Random library initialization. These functions may assume that + _hurd_init has already run (if it is going to), and POSIX.1 facilities + are initialized and available. */ + __libc_init (argc, argv, __environ); + + /* Finally, run the user program. */ + (_cthread_exit_routine != NULL ? *_cthread_exit_routine : exit) + (main (argc, argv, __environ)); + + /* Should never get here. */ + LOSE; +} + +/* Split ARGSLEN bytes at ARGS into words, breaking at NUL characters. If + ARGV is not a null pointer, store a pointer to the start of each word in + ARGV[n], and null-terminate ARGV. Return the number of words split. */ + +int +_hurd_split_args (char *args, size_t argslen, char **argv) +{ + char *p = args; + size_t n = argslen; + int argc = 0; + + while (n > 0) + { + char *end = memchr (p, '\0', n); + + if (argv) + argv[argc] = p; + ++argc; + + if (end == NULL) + /* The last argument is unterminated. */ + break; + + n -= end + 1 - p; + p = end + 1; + } + + if (argv) + argv[argc] = NULL; + return argc; +} |