glibc/elf/tst-auditmod24a.c
Adhemerval Zanella 9e94f57484 hppa: Fix bind-now audit (BZ #28857)
On hppa, a function pointer returned by la_symbind is actually a function
descriptor has the plabel bit set (bit 30).  This must be cleared to get
the actual address of the descriptor.  If the descriptor has been bound,
the first word of the descriptor is the physical address of theA function,
otherwise, the first word of the descriptor points to a trampoline in the
PLT.

This patch also adds a workaround on tests because on hppa (and it seems
to be the only ABI I have see it), some shared library adds a dynamic PLT
relocation to am empty symbol name:

$ readelf -r elf/tst-audit25mod1.so
[...]
Relocation section '.rela.plt' at offset 0x464 contains 6 entries:
 Offset     Info    Type            Sym.Value  Sym. Name + Addend
00002008  00000081 R_PARISC_IPLT                508
[...]

It breaks some assumptions on the test, where a symbol with an empty
name ("") is passed on la_symbind.

Checked on x86_64-linux-gnu and hppa-linux-gnu.
2022-02-09 08:47:42 -03:00

117 lines
2.8 KiB
C

/* Audit modules for tst-audit24a.
Copyright (C) 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
<https://www.gnu.org/licenses/>. */
#include <link.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <tst-auditmod24.h>
#define AUDIT24_COOKIE 0x1
#define AUDIT24MOD1_COOKIE 0x2
#define AUDIT24MOD2_COOKIE 0x3
#ifndef TEST_NAME
# define TEST_NAME "tst-audit24a"
#endif
#ifndef TEST_MOD
# define TEST_MOD TEST_NAME
#endif
#ifndef TEST_FUNC
# define TEST_FUNC "tst_audit24a"
#endif
unsigned int
la_version (unsigned int version)
{
return LAV_CURRENT;
}
unsigned int
la_objopen (struct link_map *map, Lmid_t lmid, uintptr_t *cookie)
{
const char *p = strrchr (map->l_name, '/');
const char *l_name = p == NULL ? TEST_NAME : p + 1;
uintptr_t ck = -1;
if (strcmp (l_name, TEST_MOD "mod1.so") == 0)
ck = AUDIT24MOD1_COOKIE;
else if (strcmp (l_name, TEST_MOD "mod2.so") == 0)
ck = AUDIT24MOD2_COOKIE;
else if (strcmp (l_name, TEST_NAME) == 0)
ck = AUDIT24_COOKIE;
*cookie = ck;
return ck == -1 ? 0 : LA_FLG_BINDFROM | LA_FLG_BINDTO;
}
static int
tst_func1 (void)
{
return 1;
}
static int
tst_func2 (void)
{
return 10;
}
#if __ELF_NATIVE_CLASS == 64
uintptr_t
la_symbind64 (Elf64_Sym *sym, unsigned int ndx,
uintptr_t *refcook, uintptr_t *defcook,
unsigned int *flags, const char *symname)
#else
uintptr_t
la_symbind32 (Elf32_Sym *sym, unsigned int ndx,
uintptr_t *refcook, uintptr_t *defcook,
unsigned int *flags, const char *symname)
#endif
{
if (*refcook == AUDIT24_COOKIE)
{
if (*defcook == AUDIT24MOD1_COOKIE)
{
/* Check if bind-now symbols are advertised to not call the PLT
hooks. */
test_symbind_flags (*flags);
if (strcmp (symname, TEST_FUNC "mod1_func1") == 0)
return (uintptr_t) tst_func1;
else if (strcmp (symname, TEST_FUNC "mod1_func2") == 0)
return sym->st_value;
abort ();
}
if (*defcook == AUDIT24MOD2_COOKIE
&& (strcmp (symname, TEST_FUNC "mod2_func1") == 0))
{
test_symbind_flags (*flags);
return (uintptr_t) tst_func2;
}
/* malloc functions. */
return sym->st_value;
}
if (symname[0] != '\0')
abort ();
return sym->st_value;
}