/* Operating system support for run-time dynamic linker. Hurd version. Copyright (C) 1995-2022 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 . */ /* In the static library, this is all handled by dl-support.c or by the vanilla definitions in the rest of the C library. */ #ifdef SHARED #include #include #include #include #include #include #include #include #include #include #include #include #include #include "hurdstartup.h" #include #include #include #include #include #include #include #include #include #include #include #include #include extern void __mach_init (void); extern int _dl_argc; extern char **_dl_argv; extern char **_environ; int __libc_enable_secure = 0; rtld_hidden_data_def (__libc_enable_secure) /* This variable contains the lowest stack address ever used. */ void *__libc_stack_end = NULL; rtld_hidden_data_def(__libc_stack_end) /* TODO: Initialize. */ void *_dl_random attribute_relro = NULL; struct hurd_startup_data *_dl_hurd_data; ElfW(Addr) _dl_sysdep_start (void **start_argptr, void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phent, ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv)) { void go (intptr_t *argdata) { char *orig_argv0; char **p; /* Cache the information in various global variables. */ _dl_argc = *argdata; _dl_argv = 1 + (char **) argdata; _environ = &_dl_argv[_dl_argc + 1]; for (p = _environ; *p++;); /* Skip environ pointers and terminator. */ orig_argv0 = _dl_argv[0]; if ((void *) p == _dl_argv[0]) { static struct hurd_startup_data nodata; _dl_hurd_data = &nodata; nodata.user_entry = (vm_address_t) ENTRY_POINT; } else _dl_hurd_data = (void *) p; GLRO(dl_platform) = NULL; /* Default to nothing known about the platform. */ __libc_enable_secure = _dl_hurd_data->flags & EXEC_SECURE; __tunables_init (_environ); /* Initialize DSO sorting algorithm after tunables. */ _dl_sort_maps_init (); #ifdef DL_SYSDEP_INIT DL_SYSDEP_INIT; #endif #ifdef DL_PLATFORM_INIT DL_PLATFORM_INIT; #endif /* Determine the length of the platform name. */ if (GLRO(dl_platform) != NULL) GLRO(dl_platformlen) = strlen (GLRO(dl_platform)); if (_dl_hurd_data->flags & EXEC_STACK_ARGS && _dl_hurd_data->user_entry == 0) _dl_hurd_data->user_entry = (vm_address_t) ENTRY_POINT; #if 0 /* XXX make this work for real someday... */ if (_dl_hurd_data->user_entry == (vm_address_t) ENTRY_POINT) /* We were invoked as a command, not as the program interpreter. The generic ld.so code supports this: it will parse the args as "ld.so PROGRAM [ARGS...]". For booting the Hurd, we support an additional special syntax: ld.so [-LIBS...] PROGRAM [ARGS...] Each LIBS word consists of "FILENAME=MEMOBJ"; for example "-/lib/libc.so=123" says that the contents of /lib/libc.so are found in a memory object whose port name in our task is 123. */ while (_dl_argc > 2 && _dl_argv[1][0] == '-' && _dl_argv[1][1] != '-') { char *lastslash, *memobjname, *p; struct link_map *l; mach_port_t memobj; error_t err; --_dl_argc; p = _dl_argv++[1] + 1; memobjname = strchr (p, '='); if (! memobjname) _dl_sysdep_fatal ("Bogus library spec: ", p, "\n", NULL); *memobjname++ = '\0'; memobj = 0; while (*memobjname != '\0') memobj = (memobj * 10) + (*memobjname++ - '0'); /* Add a user reference on the memory object port, so we will still have one after _dl_map_object_from_fd calls our `close'. */ err = __mach_port_mod_refs (__mach_task_self (), memobj, MACH_PORT_RIGHT_SEND, +1); assert_perror (err); lastslash = strrchr (p, '/'); l = _dl_map_object_from_fd (lastslash ? lastslash + 1 : p, NULL, memobj, strdup (p), 0); /* Squirrel away the memory object port where it can be retrieved by the program later. */ l->l_info[DT_NULL] = (void *) memobj; } #endif /* Call elf/rtld.c's main program. It will set everything up and leave us to transfer control to USER_ENTRY. */ (*dl_main) ((const ElfW(Phdr) *) _dl_hurd_data->phdr, _dl_hurd_data->phdrsz / sizeof (ElfW(Phdr)), (ElfW(Addr) *) &_dl_hurd_data->user_entry, NULL); /* The call above might screw a few things up. P is the location after the terminating NULL of the list of environment variables. It has to point to the Hurd startup data or if that's missing then P == ARGV[0] must hold. The startup code in init-first.c will get confused if this is not the case, so we must rearrange things to make it so. We'll recompute P and move the Hurd data or the new ARGV[0] there. Note: directly invoked ld.so can move arguments and env vars. We use memmove, since the locations might overlap. */ char **newp; for (newp = _environ; *newp++;); if (newp != p || _dl_argv[0] != orig_argv0) { if (orig_argv0 == (char *) p) { if ((char *) newp != _dl_argv[0]) { assert ((char *) newp < _dl_argv[0]); _dl_argv[0] = memmove ((char *) newp, _dl_argv[0], strlen (_dl_argv[0]) + 1); } } else { if ((void *) newp != _dl_hurd_data) memmove (newp, _dl_hurd_data, sizeof (*_dl_hurd_data)); } } { extern void _dl_start_user (void); /* Unwind the stack to ARGDATA and simulate a return from _dl_start to the RTLD_START code which will run the user's entry point. */ RETURN_TO (argdata, &_dl_start_user, _dl_hurd_data->user_entry); } } /* Set up so we can do RPCs. */ __mach_init (); /* Initialize frequently used global variable. */ GLRO(dl_pagesize) = __getpagesize (); /* See hurd/hurdstartup.c; this deals with getting information from the exec server and slicing up the arguments. Then it will call `go', above. */ _hurd_startup (start_argptr, &go); LOSE; abort (); } void _dl_sysdep_start_cleanup (void) { /* Deallocate the reply port and task port rights acquired by __mach_init. We are done with them now, and the user will reacquire them for himself when he wants them. */ __mig_dealloc_reply_port (MACH_PORT_NULL); __mach_port_deallocate (__mach_task_self (), __mach_host_self_); __mach_port_deallocate (__mach_task_self (), __mach_task_self_); } /* Minimal open/close/mmap/etc. implementation sufficient for initial loading of shared libraries. These are weak definitions so that when the dynamic linker re-relocates itself to be user-visible (for -ldl), it will get the user's definition (i.e. usually libc's). They also need to be set in the libc and ld section of sysdeps/mach/hurd/Versions, to be overridable, and in libc.abilist and ld.abilist to be checked. */ /* This macro checks that the function does not get renamed to be hidden: we do need these to be overridable by libc's. */ #define check_no_hidden(name) \ __typeof (name) __check_##name##_no_hidden \ __attribute__ ((alias (#name))) \ __attribute_copy__ (name); /* Open FILE_NAME and return a Hurd I/O for it in *PORT, or return an error. If STAT is non-zero, stat the file into that stat buffer. */ static error_t open_file (const char *file_name, int flags, mach_port_t *port, struct stat64 *stat) { enum retry_type doretry; char retryname[1024]; /* XXX string_t LOSES! */ file_t startdir; error_t err; error_t use_init_port (int which, error_t (*operate) (file_t)) { return (which < _dl_hurd_data->portarraysize ? ((*operate) (_dl_hurd_data->portarray[which])) : EGRATUITOUS); } file_t get_dtable_port (int fd) { if ((unsigned int) fd < _dl_hurd_data->dtablesize && _dl_hurd_data->dtable[fd] != MACH_PORT_NULL) { __mach_port_mod_refs (__mach_task_self (), _dl_hurd_data->dtable[fd], MACH_PORT_RIGHT_SEND, +1); return _dl_hurd_data->dtable[fd]; } errno = EBADF; return MACH_PORT_NULL; } assert (!(flags & ~(O_READ | O_EXEC | O_CLOEXEC))); flags &= ~O_CLOEXEC; startdir = _dl_hurd_data->portarray[file_name[0] == '/' ? INIT_PORT_CRDIR : INIT_PORT_CWDIR]; while (file_name[0] == '/') file_name++; err = __dir_lookup (startdir, (char *)file_name, flags, 0, &doretry, retryname, port); if (!err) err = __hurd_file_name_lookup_retry (use_init_port, get_dtable_port, __dir_lookup, doretry, retryname, O_RDONLY, 0, port); if (!err && stat) { err = __io_stat (*port, stat); if (err) __mach_port_deallocate (__mach_task_self (), *port); } return err; } check_no_hidden(__open); check_no_hidden (__open64); check_no_hidden (__open_nocancel); int weak_function __open (const char *file_name, int mode, ...) { mach_port_t port; error_t err = open_file (file_name, mode, &port, 0); if (err) return __hurd_fail (err); else return (int)port; } weak_alias (__open, __open64) weak_alias (__open, __open_nocancel) check_no_hidden(__close); check_no_hidden(__close_nocancel); int weak_function __close (int fd) { if (fd != (int) MACH_PORT_NULL) __mach_port_deallocate (__mach_task_self (), (mach_port_t) fd); return 0; } weak_alias (__close, __close_nocancel) check_no_hidden(__pread64); check_no_hidden(__pread64_nocancel); __ssize_t weak_function __pread64 (int fd, void *buf, size_t nbytes, off64_t offset) { error_t err; char *data; mach_msg_type_number_t nread; data = buf; nread = nbytes; err = __io_read ((mach_port_t) fd, &data, &nread, offset, nbytes); if (err) return __hurd_fail (err); if (data != buf) { memcpy (buf, data, nread); __vm_deallocate (__mach_task_self (), (vm_address_t) data, nread); } return nread; } libc_hidden_weak (__pread64) weak_alias (__pread64, __pread64_nocancel) check_no_hidden(__read); check_no_hidden(__read_nocancel); __ssize_t weak_function __read (int fd, void *buf, size_t nbytes) { return __pread64 (fd, buf, nbytes, -1); } libc_hidden_weak (__read) weak_alias (__read, __read_nocancel) check_no_hidden(__write); check_no_hidden(__write_nocancel); __ssize_t weak_function __write (int fd, const void *buf, size_t nbytes) { error_t err; vm_size_t nwrote; assert (fd < _hurd_init_dtablesize); err = __io_write (_hurd_init_dtable[fd], buf, nbytes, -1, &nwrote); if (err) return __hurd_fail (err); return nwrote; } libc_hidden_weak (__write) weak_alias (__write, __write_nocancel) /* This is only used for printing messages (see dl-misc.c). */ check_no_hidden(__writev); __ssize_t weak_function __writev (int fd, const struct iovec *iov, int niov) { if (fd >= _hurd_init_dtablesize) { errno = EBADF; return -1; } int i; size_t total = 0; for (i = 0; i < niov; ++i) total += iov[i].iov_len; if (total != 0) { char buf[total], *bufp = buf; error_t err; vm_size_t nwrote; for (i = 0; i < niov; ++i) bufp = (memcpy (bufp, iov[i].iov_base, iov[i].iov_len) + iov[i].iov_len); err = __io_write (_hurd_init_dtable[fd], buf, total, -1, &nwrote); if (err) return __hurd_fail (err); return nwrote; } return 0; } check_no_hidden(__libc_lseek64); off64_t weak_function __libc_lseek64 (int fd, off64_t offset, int whence) { error_t err; err = __io_seek ((mach_port_t) fd, offset, whence, &offset); if (err) return __hurd_fail (err); return offset; } check_no_hidden(__mmap); void *weak_function __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) { error_t err; vm_prot_t vmprot; vm_address_t mapaddr; mach_port_t memobj_rd, memobj_wr; vmprot = VM_PROT_NONE; if (prot & PROT_READ) vmprot |= VM_PROT_READ; if (prot & PROT_WRITE) vmprot |= VM_PROT_WRITE; if (prot & PROT_EXEC) vmprot |= VM_PROT_EXECUTE; if (flags & MAP_ANON) memobj_rd = MACH_PORT_NULL; else { assert (!(flags & MAP_SHARED)); err = __io_map ((mach_port_t) fd, &memobj_rd, &memobj_wr); if (err) return __hurd_fail (err), MAP_FAILED; if (memobj_wr != MACH_PORT_NULL) __mach_port_deallocate (__mach_task_self (), memobj_wr); } mapaddr = (vm_address_t) addr; err = __vm_map (__mach_task_self (), &mapaddr, (vm_size_t) len, 0, !(flags & MAP_FIXED), memobj_rd, (vm_offset_t) offset, flags & (MAP_COPY|MAP_PRIVATE), vmprot, VM_PROT_ALL, (flags & MAP_SHARED) ? VM_INHERIT_SHARE : VM_INHERIT_COPY); if (err == KERN_NO_SPACE && (flags & MAP_FIXED)) { /* XXX this is not atomic as it is in unix! */ /* The region is already allocated; deallocate it first. */ err = __vm_deallocate (__mach_task_self (), mapaddr, len); if (! err) err = __vm_map (__mach_task_self (), &mapaddr, (vm_size_t) len, 0, !(flags & MAP_FIXED), memobj_rd, (vm_offset_t) offset, flags & (MAP_COPY|MAP_PRIVATE), vmprot, VM_PROT_ALL, (flags & MAP_SHARED) ? VM_INHERIT_SHARE : VM_INHERIT_COPY); } if ((flags & MAP_ANON) == 0) __mach_port_deallocate (__mach_task_self (), memobj_rd); if (err) return __hurd_fail (err), MAP_FAILED; return (void *) mapaddr; } check_no_hidden(__fstat64); int weak_function __fstat64 (int fd, struct stat64 *buf) { error_t err; err = __io_stat ((mach_port_t) fd, buf); if (err) return __hurd_fail (err); return 0; } libc_hidden_def (__fstat64) check_no_hidden(__stat64); int weak_function __stat64 (const char *file, struct stat64 *buf) { error_t err; mach_port_t port; err = open_file (file, 0, &port, buf); if (err) return __hurd_fail (err); __mach_port_deallocate (__mach_task_self (), port); return 0; } libc_hidden_def (__stat64) /* This function is called by the dynamic linker (rtld.c) to check whether debugging malloc is allowed even for SUID binaries. This stub will always fail, which means that malloc-debugging is always disabled for SUID binaries. */ check_no_hidden(__access); int weak_function __access (const char *file, int type) { errno = ENOSYS; return -1; } check_no_hidden(__access_noerrno); int weak_function __access_noerrno (const char *file, int type) { return -1; } int __rtld_execve (const char *file_name, char *const argv[], char *const envp[]) { file_t file; error_t err; char *args, *env; size_t argslen, envlen; mach_port_t *ports = _dl_hurd_data->portarray; unsigned int portarraysize = _dl_hurd_data->portarraysize; file_t *dtable = _dl_hurd_data->dtable; unsigned int dtablesize = _dl_hurd_data->dtablesize; int *intarray = _dl_hurd_data->intarray; unsigned int i, j; mach_port_t *please_dealloc, *pdp; mach_port_t *portnames = NULL; mach_msg_type_number_t nportnames = 0; mach_port_type_t *porttypes = NULL; mach_msg_type_number_t nporttypes = 0; int flags; err = open_file (file_name, O_EXEC, &file, NULL); if (err) goto out; if (argv == NULL) args = NULL, argslen = 0; else if (err = __argz_create (argv, &args, &argslen)) goto outfile; if (envp == NULL) env = NULL, envlen = 0; else if (err = __argz_create (envp, &env, &envlen)) goto outargs; please_dealloc = __alloca ((portarraysize + dtablesize) * sizeof (mach_port_t)); pdp = please_dealloc; /* Get all ports that we may not know about and we should thus destroy. */ err = __mach_port_names (__mach_task_self (), &portnames, &nportnames, &porttypes, &nporttypes); if (err) goto outenv; if (nportnames != nporttypes) { err = EGRATUITOUS; goto outenv; } for (i = 0; i < portarraysize; ++i) if (ports[i] != MACH_PORT_NULL) { *pdp++ = ports[i]; for (j = 0; j < nportnames; j++) if (portnames[j] == ports[i]) portnames[j] = MACH_PORT_NULL; } for (i = 0; i < dtablesize; ++i) if (dtable[i] != MACH_PORT_NULL) { *pdp++ = dtable[i]; for (j = 0; j < nportnames; j++) if (portnames[j] == dtable[i]) portnames[j] = MACH_PORT_NULL; } /* Pack ports to be destroyed together. */ for (i = 0, j = 0; i < nportnames; i++) { if (portnames[i] == MACH_PORT_NULL) continue; if (j != i) portnames[j] = portnames[i]; j++; } nportnames = j; flags = 0; #ifdef EXEC_SIGTRAP if (__sigismember (&intarray[INIT_TRACEMASK], SIGKILL)) flags |= EXEC_SIGTRAP; #endif err = __file_exec_paths (file, __mach_task_self (), flags, file_name, file_name[0] == '/' ? file_name : "", args, argslen, env, envlen, dtable, MACH_MSG_TYPE_COPY_SEND, dtablesize, ports, MACH_MSG_TYPE_COPY_SEND, portarraysize, intarray, INIT_INT_MAX, please_dealloc, pdp - please_dealloc, portnames, nportnames); /* Oh well. Might as well be tidy. */ outenv: free (env); outargs: free (args); outfile: __mach_port_deallocate (__mach_task_self (), file); out: return err; } check_no_hidden(__getpid); pid_t weak_function __getpid (void) { pid_t pid, ppid; int orphaned; if (__proc_getpids (_dl_hurd_data->portarray[INIT_PORT_PROC], &pid, &ppid, &orphaned)) return -1; return pid; } /* We need this alias to satisfy references from libc_pic.a objects that were affected by the libc_hidden_proto declaration for __getpid. */ strong_alias (__getpid, __GI___getpid) /* This is called only in some strange cases trying to guess a value for $ORIGIN for the executable. The dynamic linker copes with getcwd failing (dl-object.c), and it's too much hassle to include the functionality here. (We could, it just requires duplicating or reusing getcwd.c's code but using our special lookup function as in `open', above.) */ check_no_hidden(__getcwd); char *weak_function __getcwd (char *buf, size_t size) { errno = ENOSYS; return NULL; } /* This is used by dl-tunables.c to strdup strings. We can just make this a mere allocation. */ check_no_hidden(__sbrk); void *weak_function __sbrk (intptr_t increment) { vm_address_t addr; __vm_allocate (__mach_task_self (), &addr, increment, 1); return (void *) addr; } /* This is only used by hurdlookup for the /dev/fd/nnn magic. * We avoid pulling the whole libc implementation, and we can keep this hidden. */ unsigned long int weak_function __strtoul_internal (const char *nptr, char **endptr, int base, int group) { assert (base == 0 || base == 10); assert (group == 0); return _dl_strtoul (nptr, endptr); } /* We need this alias to satisfy references from libc_pic.a objects that were affected by the libc_hidden_proto declaration for __strtoul_internal. */ strong_alias (__strtoul_internal, __GI___strtoul_internal) strong_alias (__strtoul_internal, __GI_____strtoul_internal) check_no_hidden(_exit); void weak_function attribute_hidden _exit (int status) { __proc_mark_exit (_dl_hurd_data->portarray[INIT_PORT_PROC], W_EXITCODE (status, 0), 0); while (__task_terminate (__mach_task_self ())) __mach_task_self_ = (__mach_task_self) (); LOSE; abort (); } /* We need this alias to satisfy references from libc_pic.a objects that were affected by the libc_hidden_proto declaration for _exit. */ strong_alias (_exit, __GI__exit) /* Try to get a machine dependent instruction which will make the program crash. This is used in case everything else fails. */ #include #ifndef ABORT_INSTRUCTION /* No such instruction is available. */ # define ABORT_INSTRUCTION #endif check_no_hidden(abort); void weak_function abort (void) { /* Try to abort using the system specific command. */ ABORT_INSTRUCTION; /* If the abort instruction failed, exit. */ _exit (127); /* If even this fails, make sure we never return. */ while (1) /* Try for ever and ever. */ ABORT_INSTRUCTION; } /* We need this alias to satisfy references from libc_pic.a objects that were affected by the libc_hidden_proto declaration for abort. */ strong_alias (abort, __GI_abort) strong_alias (abort, __GI___fortify_fail) strong_alias (abort, __GI___assert_fail) strong_alias (abort, __GI___assert_perror_fail) /* This function is called by interruptible RPC stubs. For initial dynamic linking, just use the normal mach_msg. Since this defn is weak, the real defn in libc.so will override it if we are linked into the user program (-ldl). */ error_t weak_function _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg, mach_msg_option_t option, mach_msg_size_t send_size, mach_msg_size_t rcv_size, mach_port_t rcv_name, mach_msg_timeout_t timeout, mach_port_t notify) { return __mach_msg (msg, option, send_size, rcv_size, rcv_name, timeout, notify); } void _dl_show_auxv (void) { /* There is nothing to print. Hurd has no auxiliary vector. */ } void weak_function _dl_init_first (int argc, ...) { /* This no-op definition only gets used if libc is not linked in. */ } #endif /* SHARED */