glibc/sysdeps/generic/dl-prop.h
H.J. Lu 1bd888d0b7 Initial support for GNU_PROPERTY_1_NEEDED
1. Add GNU_PROPERTY_1_NEEDED:

 #define GNU_PROPERTY_1_NEEDED      GNU_PROPERTY_UINT32_OR_LO

to indicate the needed properties by the object file.
2. Add GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS:

 #define GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS (1U << 0)

to indicate that the object file requires canonical function pointers and
cannot be used with copy relocation.
3. Scan GNU_PROPERTY_1_NEEDED property and store it in l_1_needed.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-10-07 10:26:08 -07:00

61 lines
2.1 KiB
C

/* Support for GNU properties. Generic version.
Copyright (C) 2018-2021 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
<https://www.gnu.org/licenses/>. */
#ifndef _DL_PROP_H
#define _DL_PROP_H
/* The following functions are used by the dynamic loader and the
dlopen machinery to process PT_NOTE and PT_GNU_PROPERTY entries in
the binary or shared object. The notes can be used to change the
behaviour of the loader, and as such offer a flexible mechanism
for hooking in various checks related to ABI tags or implementing
"flag day" ABI transitions. */
static inline void __attribute__ ((always_inline))
_rtld_main_check (struct link_map *m, const char *program)
{
}
static inline void __attribute__ ((always_inline))
_dl_open_check (struct link_map *m)
{
}
static inline void __attribute__ ((always_inline))
_dl_process_pt_note (struct link_map *l, int fd, const ElfW(Phdr) *ph)
{
}
/* Called for each property in the NT_GNU_PROPERTY_TYPE_0 note of L,
processing of the properties continues until this returns 0. */
static inline int __attribute__ ((always_inline))
_dl_process_gnu_property (struct link_map *l, int fd, uint32_t type,
uint32_t datasz, void *data)
{
/* Continue until GNU_PROPERTY_1_NEEDED is found. */
if (type == GNU_PROPERTY_1_NEEDED)
{
if (datasz == 4)
l->l_1_needed = *(unsigned int *) data;
return 0;
}
return 1;
}
#endif /* _DL_PROP_H */