glibc/sysdeps/aarch64/tst-audit26mod.h
Ben Woodard b118bce87a elf: Fix runtime linker auditing on aarch64 (BZ #26643)
The rtld audit support show two problems on aarch64:

  1. _dl_runtime_resolve does not preserve x8, the indirect result
      location register, which might generate wrong result calls
      depending of the function signature.

  2. The NEON Q registers pushed onto the stack by _dl_runtime_resolve
     were twice the size of D registers extracted from the stack frame by
     _dl_runtime_profile.

While 2. might result in wrong information passed on the PLT tracing,
1. generates wrong runtime behaviour.

The aarch64 rtld audit support is changed to:

  * Both La_aarch64_regs and La_aarch64_retval are expanded to include
    both x8 and the full sized NEON V registers, as defined by the
    ABI.

  * dl_runtime_profile needed to extract registers saved by
    _dl_runtime_resolve and put them into the new correctly sized
    La_aarch64_regs structure.

  * The LAV_CURRENT check is change to only accept new audit modules
    to avoid the undefined behavior of not save/restore x8.

  * Different than other architectures, audit modules older than
    LAV_CURRENT are rejected (both La_aarch64_regs and La_aarch64_retval
    changed their layout and there are no requirements to support multiple
    audit interface with the inherent aarch64 issues).

  * A new field is also reserved on both La_aarch64_regs and
    La_aarch64_retval to support variant pcs symbols.

Similar to x86, a new La_aarch64_vector type to represent the NEON
register is added on the La_aarch64_regs (so each type can be accessed
directly).

Since LAV_CURRENT was already bumped to support bind-now, there is
no need to increase it again.

Checked on aarch64-linux-gnu.

Co-authored-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit ce9a68c57c)

Resolved conflicts:
	NEWS
	elf/rtld.c
2022-04-12 13:33:10 -04:00

51 lines
1.4 KiB
C

/* Check LD_AUDIT for aarch64 specific ABI.
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/>. */
#ifndef _TST_AUDIT27MOD_H
#define _TST_AUDIT27MOD_H 1
#include <array_length.h>
struct large_struct
{
char a[16];
short b[8];
long int c[4];
};
static inline struct large_struct
set_large_struct (char a, short b, long int c)
{
struct large_struct r;
for (int i = 0; i < array_length (r.a); i++)
r.a[i] = a;
for (int i = 0; i < array_length (r.b); i++)
r.b[i] = b;
for (int i = 0; i < array_length (r.c); i++)
r.c[i] = c;
return r;
}
#define ARG1 0x12
#define ARG2 0x1234
#define ARG3 0x12345678
struct large_struct tst_audit26_func (char a, short b, long int c);
#endif