glibc/sysdeps/hppa/dl-fptr.c

212 lines
5.1 KiB
C

/* Make dynamic PLABELs for function pointers. HPPA version.
Copyright (C) 1999, 2000, 2002 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 <unistd.h>
#include <string.h>
#include <sys/param.h>
#include <sys/mman.h>
#include <link.h>
#include <errno.h>
#include <ldsodefs.h>
#include <elf/dynamic-link.h>
#include <dl-machine.h>
#ifdef _LIBC_REENTRANT
# include <pt-machine.h>
/* Remember, we use 0 to mean that a lock is taken on PA-RISC. */
static int __hppa_fptr_lock = 1;
#endif
/* Because ld.so is now versioned, these functions can be in their own
file; no relocations need to be done to call them. Of course, if
ld.so is not versioned... */
#if 0
#ifndef DO_VERSIONING
# error "This will not work with versioning turned off, sorry."
#endif
#endif
#ifdef MAP_ANON
/* The fd is not examined when using MAP_ANON. */
# define ANONFD -1
#else
# define ANONFD GL(dl_zerofd)
#endif
struct hppa_fptr __boot_ldso_fptr[HPPA_BOOT_FPTR_SIZE];
struct hppa_fptr *__fptr_root = NULL;
struct hppa_fptr *__fptr_next = __boot_ldso_fptr;
static struct hppa_fptr *__fptr_free = NULL;
int __fptr_count = HPPA_BOOT_FPTR_SIZE;
Elf32_Addr
__hppa_make_fptr (const struct link_map *sym_map, Elf32_Addr value,
struct hppa_fptr **root, struct hppa_fptr *mem)
{
struct hppa_fptr **loc;
struct hppa_fptr *f;
#ifdef _LIBC_REENTRANT
/* Make sure we are alone. We don't need a lock during bootstrap. */
if (mem == NULL)
while (testandset (&__hppa_fptr_lock));
#endif
/* Search the sorted linked list for an existing entry for this
symbol. */
loc = root;
f = *loc;
while (f != NULL && f->func <= value)
{
if (f->func == value)
goto found;
loc = &f->next;
f = *loc;
}
/* Not found. Create a new one. */
if (mem != NULL)
f = mem;
else if (__fptr_free != NULL)
{
f = __fptr_free;
__fptr_free = f->next;
}
else
{
if (__fptr_count == 0)
{
#ifndef MAP_ANON
# define MAP_ANON 0
if (GL(dl_zerofd) == -1)
{
GL(dl_zerofd) = _dl_sysdep_open_zero_fill ();
if (GL(dl_zerofd) == -1)
{
__close (fd);
_dl_signal_error (errno, NULL, NULL,
"cannot open zero fill device");
}
}
#endif
__fptr_next = __mmap (0, GL(dl_pagesize), PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE, ANONFD, 0);
if (__fptr_next == MAP_FAILED)
_dl_signal_error(errno, NULL, NULL, "cannot map page for fptr");
__fptr_count = GL(dl_pagesize) / sizeof (struct hppa_fptr);
}
f = __fptr_next++;
__fptr_count--;
}
f->func = value;
/* GOT has already been relocated in elf_get_dynamic_info - don't
try to relocate it again. */
f->gp = sym_map->l_info[DT_PLTGOT]->d_un.d_ptr;
f->next = *loc;
*loc = f;
found:
#ifdef _LIBC_REENTRANT
/* Release the lock. Again, remember, zero means the lock is taken! */
if (mem == NULL)
__hppa_fptr_lock = 1;
#endif
/* Set bit 30 to indicate to $$dyncall that this is a PLABEL. */
return (Elf32_Addr) f | 2;
}
void
_dl_unmap (struct link_map *map)
{
struct hppa_fptr **floc;
struct hppa_fptr *f;
struct hppa_fptr **lloc;
struct hppa_fptr *l;
__munmap ((void *) map->l_map_start, map->l_map_end - map->l_map_start);
#ifdef _LIBC_REENTRANT
/* Make sure we are alone. */
while (testandset (&__hppa_fptr_lock));
#endif
/* Search the sorted linked list for the first entry for this object. */
floc = &__fptr_root;
f = *floc;
while (f != NULL && f->func < map->l_map_start)
{
floc = &f->next;
f = *floc;
}
/* We found one. */
if (f != NULL && f->func < map->l_map_end)
{
/* Get the last entry. */
lloc = floc;
l = f;
while (l && l->func < map->l_map_end)
{
lloc = &l->next;
l = *lloc;
}
/* Updated FPTR. */
*floc = l;
/* Prepend them to the free list. */
*lloc = __fptr_free;
__fptr_free = f;
}
#ifdef _LIBC_REENTRANT
/* Release the lock. */
__hppa_fptr_lock = 1;
#endif
}
Elf32_Addr
_dl_lookup_address (const void *address)
{
Elf32_Addr addr = (Elf32_Addr) address;
struct hppa_fptr *f;
#ifdef _LIBC_REENTRANT
/* Make sure we are alone. */
while (testandset (&__hppa_fptr_lock));
#endif
for (f = __fptr_root; f != NULL; f = f->next)
if (f == address)
{
addr = f->func;
break;
}
#ifdef _LIBC_REENTRANT
/* Release the lock. */
__hppa_fptr_lock = 1;
#endif
return addr;
}