glibc/sysdeps/aarch64/tst-vpcs.c
Szabolcs Nagy e156dabc76 aarch64: Add variant PCS lazy binding test [BZ #26798]
This test fails without bug 26798 fixed because some integer registers
likely get clobbered by lazy binding and variant PCS only allows x16
and x17 to be clobbered at call time.

The test requires binutils 2.32.1 or newer for handling variant PCS
symbols. SVE registers are not covered by this test, to avoid the
complexity of handling multiple compile- and runtime feature support
cases.
2020-11-02 09:39:24 +00:00

79 lines
2.3 KiB
C

/* Test that variant PCS calls don't clobber registers with lazy binding.
Copyright (C) 2020 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 <stdint.h>
#include <stdio.h>
#include <support/check.h>
struct regs
{
uint64_t x[32];
union {
long double q[32];
uint64_t u[64];
} v;
};
/* Gives the registers in the caller and callee around a variant PCS call.
Most registers are initialized from BEFORE in the caller so they can
have values that likely show clobbers. Register state extensions such
as SVE is not covered here, only the base registers. */
void vpcs_call_regs (struct regs *after, struct regs *before);
static int
do_test (void)
{
struct regs before, after;
int err = 0;
unsigned char *p = (unsigned char *)&before;
for (int i = 0; i < sizeof before; i++)
p[i] = i & 0xff;
vpcs_call_regs (&after, &before);
for (int i = 0; i < 32; i++)
if (before.x[i] != after.x[i])
{
if (i == 16 || i == 17)
/* Variant PCS allows clobbering x16 and x17. */
continue;
err++;
printf ("x%d: before: 0x%016llx after: 0x%016llx\n",
i,
(unsigned long long)before.x[i],
(unsigned long long)after.x[i]);
}
for (int i = 0; i < 64; i++)
if (before.v.u[i] != after.v.u[i])
{
err++;
printf ("v%d: before: 0x%016llx %016llx after: 0x%016llx %016llx\n",
i/2,
(unsigned long long)before.v.u[2*(i/2)+1],
(unsigned long long)before.v.u[2*(i/2)],
(unsigned long long)after.v.u[2*(i/2)+1],
(unsigned long long)after.v.u[2*(i/2)]);
}
if (err)
FAIL_EXIT1 ("The variant PCS call clobbered %d registers.\n", err);
return 0;
}
#include <support/test-driver.c>