glibc/support/tst-xsigstack.c
Zack Weinberg fbbc9a4e34 Tests for minimal signal handler functionality in MINSIGSTKSZ space.
There is general agreement that the very short list of things that ISO
C says you can do in an async signal handler should all work when the
handler is running on an alternate signal stack with only MINSIGSTKSZ
space.  This patch adds tests to make sure those things do work.

To facilitate this, there is a new set of test support routines for
setting up alternate signal stacks; see support/xsignal.h for the API.

         * support/xsignal.h (xalloc_sigstack, xfree_sigstack)
         (xget_sigstack_location): New test support functions.
         * support/xsigstack.c: New file, implementing them.
         * support/tst-xsigstack.c: New test for them.
         * support/Makefile: Update.

         * signal/tst-minsigstksz-1.c
         * signal/tst-minsigstksz-2.c
         * signal/tst-minsigstksz-3.c
         * signal/tst-minsigstksz-3a.c
         * signal/tst-minsigstksz-4.c: New tests.
         * signal/Makefile: Run them.
2019-01-16 09:04:10 -05:00

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C

/* Test of sigaltstack wrappers.
Copyright (C) 2019 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 <support/xsignal.h>
#include <support/support.h>
#include <support/xunistd.h>
#include <support/check.h>
#include <stdint.h>
#include <stdio.h>
static volatile uintptr_t handler_stackaddr;
static void
handler (int unused)
{
int var;
handler_stackaddr = (uintptr_t) &var;
}
int
do_test (void)
{
void *sstk = xalloc_sigstack (0);
unsigned char *sp;
size_t size;
xget_sigstack_location (sstk, &sp, &size);
printf ("signal stack installed: sp=%p size=%zu\n", sp, size);
struct sigaction sa;
sa.sa_handler = handler;
sa.sa_flags = SA_RESTART | SA_ONSTACK;
sigfillset (&sa.sa_mask);
if (sigaction (SIGUSR1, &sa, 0))
FAIL_RET ("sigaction (SIGUSR1, handler): %m\n");
raise (SIGUSR1);
uintptr_t haddr = handler_stackaddr;
printf ("address of handler local variable: %p\n", (void *)haddr);
TEST_VERIFY ((uintptr_t)sp < haddr);
TEST_VERIFY (haddr < (uintptr_t)sp + size);
xfree_sigstack (sstk);
return 0;
}
#include <support/test-driver.c>