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Diffstat (limited to 'REORG.TODO/sysdeps/mach/hurd/i386/init-first.c')
| -rw-r--r-- | REORG.TODO/sysdeps/mach/hurd/i386/init-first.c | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/mach/hurd/i386/init-first.c b/REORG.TODO/sysdeps/mach/hurd/i386/init-first.c new file mode 100644 index 0000000000..6a6a694719 --- /dev/null +++ b/REORG.TODO/sysdeps/mach/hurd/i386/init-first.c @@ -0,0 +1,410 @@ +/* Initialization code run first thing by the ELF startup code. For i386/Hurd. + Copyright (C) 1995-2017 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, see + <http://www.gnu.org/licenses/>. */ + +#include <assert.h> +#include <ctype.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 **); +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); + } + else + { + /* Initialize data structures so the additional libc can do RPCs. */ + __mach_init (); + } + + /* 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); + + /* Initialize ctype data. */ + __ctype_init (); + +#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; + + 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 + /* With a new enough linker (binutils-2.23 or better), + the magic __ehdr_start symbol will be available and + __libc_start_main will have done this that way already. */ + if (_dl_phdr == NULL) + { + /* 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 __executable_start; + const ElfW(Ehdr) *const ehdr = &__executable_start; + _dl_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); + + __libc_stack_end = newsp; + + /* 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. */ + /* The following expression would typically be written as + ``__builtin_return_address (0)''. But, for example, GCC 4.4.6 doesn't + recognize that this read operation may alias the following write + operation, and thus is free to reorder the two, clobbering the + original return address. */ + *--newsp = *((int *) __builtin_frame_address (0) + 1); + /* GCC 4.4.6 also wants us to force loading *NEWSP already here. */ + asm volatile ("# %0" : : "X" (*newsp)); + *((void **) __builtin_frame_address (0) + 1) = &switch_stacks; + /* Force NEWSP into %eax and &init1 into %ecx, 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. */ + /* The following expression would typically be written as + ``__builtin_return_address (0)''. But, for example, GCC 4.4.6 doesn't + recognize that this read operation may alias the following write + operation, and thus is free to reorder the two, clobbering the + original return address. */ + usercode = *((int *) __builtin_frame_address (0) + 1); + /* GCC 4.4.6 also wants us to force loading USERCODE already here. */ + asm volatile ("# %0" : : "X" (usercode)); + *((void **) __builtin_frame_address (0) + 1) = &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 (int argc, ...) +{ + first_init (); + + /* If we use ``__builtin_frame_address (0) + 2'' here, GCC gets confused. */ + init (&argc); +} +#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 (int argc, ...) + { + /* If we use ``__builtin_frame_address (0) + 2'' here, GCC gets + confused. */ + init ((int *) &argc); + } + + /* 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 (); +} |