mirror of
https://sourceware.org/git/glibc.git
synced 2025-11-03 20:53:13 +03:00
08ac6bed14
Verify that setcontext works with gaps above and below the newly allocated shadow stack. * sysdeps/unix/sysv/linux/x86/Makefile (tests): Add tst-cet-setcontext-1 if CET is enabled. (CFLAGS-tst-cet-setcontext-1.c): Add -mshstk. * sysdeps/unix/sysv/linux/x86/tst-cet-setcontext-1.c: New file.
128 lines
3.5 KiB
C
128 lines
3.5 KiB
C
/* Check getcontext and setcontext on the context from makecontext
|
|
with shadow stack.
|
|
Copyright (C) 2018 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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <stdio.h>
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <ucontext.h>
|
|
#include <unistd.h>
|
|
#include <sys/mman.h>
|
|
#include <stdatomic.h>
|
|
#include <x86intrin.h>
|
|
|
|
static ucontext_t ctx[5];
|
|
static atomic_int done;
|
|
|
|
static void
|
|
__attribute__((noinline, noclone))
|
|
f2 (void)
|
|
{
|
|
printf ("start f2\n");
|
|
done++;
|
|
if (setcontext (&ctx[2]) != 0)
|
|
{
|
|
printf ("%s: setcontext: %m\n", __FUNCTION__);
|
|
exit (EXIT_FAILURE);
|
|
}
|
|
}
|
|
|
|
static void
|
|
f1 (void)
|
|
{
|
|
printf ("start f1\n");
|
|
if (getcontext (&ctx[2]) != 0)
|
|
{
|
|
printf ("%s: getcontext: %m\n", __FUNCTION__);
|
|
exit (EXIT_FAILURE);
|
|
}
|
|
if (done)
|
|
exit (EXIT_SUCCESS);
|
|
f2 ();
|
|
}
|
|
|
|
static int
|
|
do_test (void)
|
|
{
|
|
char st1[32768];
|
|
puts ("making contexts");
|
|
if (getcontext (&ctx[0]) != 0)
|
|
{
|
|
printf ("%s: getcontext: %m\n", __FUNCTION__);
|
|
exit (EXIT_FAILURE);
|
|
}
|
|
if (getcontext (&ctx[1]) != 0)
|
|
{
|
|
printf ("%s: getcontext: %m\n", __FUNCTION__);
|
|
exit (EXIT_FAILURE);
|
|
}
|
|
|
|
ctx[3].uc_stack.ss_sp = st1;
|
|
ctx[3].uc_stack.ss_size = sizeof st1;
|
|
ctx[3].uc_link = &ctx[0];
|
|
makecontext (&ctx[3], (void (*) (void)) f1, 0);
|
|
|
|
ctx[1].uc_stack.ss_sp = st1;
|
|
ctx[1].uc_stack.ss_size = sizeof st1;
|
|
ctx[1].uc_link = &ctx[0];
|
|
makecontext (&ctx[1], (void (*) (void)) f1, 0);
|
|
|
|
ctx[4].uc_stack.ss_sp = st1;
|
|
ctx[4].uc_stack.ss_size = sizeof st1;
|
|
ctx[4].uc_link = &ctx[0];
|
|
makecontext (&ctx[4], (void (*) (void)) f1, 0);
|
|
|
|
/* NB: When shadow stack is enabled, makecontext calls arch_prctl
|
|
with ARCH_CET_ALLOC_SHSTK to allocate a new shadow stack which
|
|
can be unmapped. The base address and size of the new shadow
|
|
stack are returned in __ssp[1] and __ssp[2]. makecontext is
|
|
called for CTX1, CTX3 and CTX4. But only CTX1 is used. New
|
|
shadow stacks are allocated in the order of CTX3, CTX1, CTX4.
|
|
It is very likely that CTX1's shadow stack is placed between
|
|
CTX3 and CTX4. We munmap CTX3's and CTX4's shadow stacks to
|
|
create gaps above and below CTX1's shadow stack. We check
|
|
that setcontext CTX1 works correctly in this case. */
|
|
if (_get_ssp () != 0)
|
|
{
|
|
if (ctx[3].__ssp[1] != 0
|
|
&& munmap ((void *) (uintptr_t) ctx[3].__ssp[1],
|
|
(size_t) ctx[3].__ssp[2]) != 0)
|
|
{
|
|
printf ("%s: munmap: %m\n", __FUNCTION__);
|
|
exit (EXIT_FAILURE);
|
|
}
|
|
|
|
if (ctx[4].__ssp[1] != 0
|
|
&& munmap ((void *) (uintptr_t) ctx[4].__ssp[1],
|
|
(size_t) ctx[4].__ssp[2]) != 0)
|
|
{
|
|
printf ("%s: munmap: %m\n", __FUNCTION__);
|
|
exit (EXIT_FAILURE);
|
|
}
|
|
}
|
|
|
|
if (setcontext (&ctx[1]) != 0)
|
|
{
|
|
printf ("%s: setcontext: %m\n", __FUNCTION__);
|
|
exit (EXIT_FAILURE);
|
|
}
|
|
exit (EXIT_FAILURE);
|
|
}
|
|
|
|
#include <support/test-driver.c>
|