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On Wed, Jul 11, 2001 at 11:08:56AM -0700, Ulrich Drepper wrote: > Jakub Jelinek <jakub@redhat.com> writes: > > > How about this? > > This one does not have callback, but of course can be easily changed into > > one if that is desired. > > This is not good. The reason to use a callback function is for the > caller (i.e., this new function) to allocate the memory for the data > structure which is passed. This way the implementation can extend the > data structure without having compatibility problems. The callback > should take a pointer to a data structure and a parameter with the > size. > > > It does not do any locking (yet), but AFAIC dlsym and other > > functions don't do any locking either. > > dlopen does locking. dlsym doesn't have to. If you call dlsym while > unloading the object it's your own fault. Ok, is this what you meant? Users of dl_iterate_phdr will just need to be careful not to do anything which would result in dlopen or dlclose, because that would be a deadlock. BTW: It is not just gcc/ia-64 fde-glibc.c which will need to use this interface, apparently boehm-gc has the same issues and I've run into them on i686 today. This still does nothing about dynamic linker's phdr/phnum, what's your opinion about it? 2001-07-11 Jakub Jelinek <jakub@redhat.com> * elf/Makefile (routines): Add dl-iteratephdr and dl-iteratephdrs. (elide-routines.os): Add dl-iteratephdrs. * elf/dl-iteratephdr.c: New. * elf/link.h (struct dl_phdr_info, dl_iterate_phdr): New. * elf/Versions (dl_iterate_phdr): Add at GLIBC_2.2.4. * include/link.h (struct dl_phdr_info): New. (dl_iterate_phdr, __dl_iterate_phdr): New. * sysdeps/generic/dl-iteratephdrs.c: New. * sysdeps/unix/sysv/linux/ia64/dl-iteratephdrs.c: New. --- libc/elf/Makefile.jj Mon Jun 25 10:50:33 2001 +++ libc/elf/Makefile Wed Jul 11 20:35:30 2001 @@ -21,8 +21,9 @@ subdir := elf headers = elf.h bits/elfclass.h link.h -routines = $(dl-routines) dl-open dl-close dl-support \ - dl-addr enbl-secure dl-profstub dl-origin dl-libc dl-sym +routines = $(dl-routines) dl-open dl-close dl-support dl-iteratephdr \ + dl-iteratephdrs dl-addr enbl-secure dl-profstub dl-origin \ + dl-libc dl-sym # The core dynamic linking functions are in libc for the static and # profiled libraries. @@ -31,7 +32,7 @@ dl-routines = $(addprefix dl-,load cache version profile) all-dl-routines = $(dl-routines) $(sysdep-dl-routines) # But they are absent from the shared libc, because that code is in ld.so. -elide-routines.os = $(all-dl-routines) dl-support enbl-secure +elide-routines.os = $(all-dl-routines) dl-support enbl-secure dl-iteratephdrs # ld.so uses those routines, plus some special stuff for being the program # interpreter and operating independent of libc. --- libc/elf/link.h.jj Wed May 23 09:21:40 2001 +++ libc/elf/link.h Wed Jul 11 20:53:15 2001 @@ -1,6 +1,6 @@ /* Data structure for communication from the run-time dynamic linker for loaded ELF shared objects. - Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc. + Copyright (C) 1995-1999, 2000, 2001 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 @@ -91,5 +91,24 @@ struct link_map ElfW(Dyn) *l_ld; /* Dynamic section of the shared object. */ struct link_map *l_next, *l_prev; /* Chain of loaded objects. */ }; + +#ifdef __USE_GNU + +struct dl_phdr_info + { + ElfW(Addr) dlpi_addr; + const char *dlpi_name; + const ElfW(Phdr) *dlpi_phdr; + ElfW(Half) dlpi_phnum; + }; + +__BEGIN_DECLS + +int dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, + size_t size)) __THROW; + +__END_DECLS + +#endif #endif /* link.h */ --- libc/elf/Versions.jj Wed May 23 09:21:37 2001 +++ libc/elf/Versions Wed Jul 11 20:20:20 2001 @@ -14,6 +14,9 @@ libc { # functions used in other libraries _dl_sym; _dl_vsym; } + GLIBC_2.2.4 { + dl_iterate_phdr; + } } ld { --- libc/elf/dl-iteratephdr.c.jj Wed Jul 11 17:19:29 2001 +++ libc/elf/dl-iteratephdr.c Wed Jul 11 20:53:51 2001 @@ -0,0 +1,60 @@ +/* Get loaded objects program headers. + Copyright (C) 2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Jakub Jelinek <jakub@redhat.com>, 2001. + + 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <errno.h> +#include <ldsodefs.h> +#include <stddef.h> +#include <bits/libc-lock.h> + +#ifdef SHARED + +__libc_lock_define (extern, _dl_load_lock) + +int +__dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, + size_t size)) +{ + struct link_map *l; + struct dl_phdr_info info; + int ret = 0; + + /* Make sure we are alone. */ + __libc_lock_lock (_dl_load_lock); + + for (l = _dl_loaded; l != NULL; l = l->l_next) + { + info.dlpi_addr = l->l_addr; + info.dlpi_name = l->l_name; + info.dlpi_phdr = l->l_phdr; + info.dlpi_phnum = l->l_phnum; + ret = callback (&info, sizeof (struct dl_phdr_info)); + if (ret) + break; + } + + /* Release the lock. */ + __libc_lock_unlock (_dl_load_lock); + + return ret; +} + +weak_alias (__dl_iterate_phdr, dl_iterate_phdr); + +#endif --- libc/include/link.h.jj Mon Jun 25 10:50:33 2001 +++ libc/include/link.h Wed Jul 11 20:52:46 2001 @@ -239,4 +239,17 @@ struct link_map ElfW(Word) l_machine_specific[2]; }; +struct dl_phdr_info + { + ElfW(Addr) dlpi_addr; + const char *dlpi_name; + const ElfW(Phdr) *dlpi_phdr; + ElfW(Half) dlpi_phnum; + }; + +int dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, + size_t size)); +int __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, + size_t size)); + #endif /* link.h */ --- libc/sysdeps/generic/dl-iteratephdrs.c.jj Wed Jul 11 17:52:27 2001 +++ libc/sysdeps/generic/dl-iteratephdrs.c Wed Jul 11 20:54:17 2001 @@ -0,0 +1,31 @@ +/* Get static program's program headers. + Copyright (C) 2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Jakub Jelinek <jakub@redhat.com>, 2001. + + 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <errno.h> +#include <elf/link.h> +#include <stddef.h> + +int +dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, + size_t size)) +{ + __set_errno (ENOSYS); + return -1; +} --- libc/sysdeps/unix/sysv/linux/ia64/dl-iteratephdrs.c.jj Wed Jul 11 17:52:27 2001 +++ libc/sysdeps/unix/sysv/linux/ia64/dl-iteratephdrs.c Wed Jul 11 20:55:02 2001 @@ -0,0 +1,56 @@ +/* Get static program's program headers. IA-64 version. + Copyright (C) 2001 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Jakub Jelinek <jakub@redhat.com>, 2001. + + 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <assert.h> +#include <errno.h> +#include <elf/link.h> +#include <stddef.h> + +extern unsigned long ip_segrel; + +asm (".section .rodata; ip_segrel: data8 @segrel(ip#); .previous"); + +int +dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, + size_t size)) +{ + char *ip; + ElfW(Ehdr) *ehdr; + struct dl_phdr_info info; + + asm ("ip: mov %0 = ip" : "=r" (ip)); + ehdr = (ElfW(Ehdr) *) (ip - ip_segrel); + + assert (ehdr->e_ident[0] == 0x7f + && ehdr->e_ident[1] == 'E' + && ehdr->e_ident[2] == 'L' + && ehdr->e_ident[3] == 'F' + && ehdr->e_ident[EI_CLASS] == ELFCLASS64 + && ehdr->e_ident[EI_DATA] == ELFDATA2LSB + && ehdr->e_machine == EM_IA_64 + && ehdr->e_type == ET_EXEC); + + info.dlpi_addr = 0; + info.dlpi_name = NULL; + info.dlpi_phdr = (ElfW(Phdr) *) ((char *) ehdr + ehdr->e_phoff); + info.dlpi_phnum = ehdr->e_phnum; + + return callback (&info, sizeof (struct dl_phdr_info)); +} Jakub
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