70 lines
2.4 KiB
C
70 lines
2.4 KiB
C
/* Tests of signal delivery on an alternate stack (_exit).
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Copyright (C) 2019 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <support/xsignal.h>
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#include <support/support.h>
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#include <support/check.h>
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#include <unistd.h>
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/* C2011 7.4.1.1p5 specifies that only the following operations are
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guaranteed to be well-defined inside an asynchronous signal handler:
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* any operation on a lock-free atomic object
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* assigning a value to an object declared as volatile sig_atomic_t
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* calling abort, _Exit, quick_exit, or signal
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* signal may only be called with its first argument equal to the
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number of the signal that caused the handler to be called
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We use this list as a guideline for the set of operations that ought
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also to be safe in a _synchronous_ signal delivered on an alternate
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signal stack with only MINSIGSTKSZ bytes of space.
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This test program tests calls to _exit, which is the same function
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as _Exit, but specified by POSIX rather than ISO C. For reasons
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unknown to the author of this program, the C committee did not
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think it could standardize _exit under that name; regardless, in a
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POSIX-conformant environment, they should be completely
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interchangeable. */
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#define EXPECTED_STATUS 3
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static void
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handler (int unused)
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{
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_exit (EXPECTED_STATUS);
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}
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int
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do_test (void)
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{
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void *sstk = xalloc_sigstack (0);
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struct sigaction sa;
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sa.sa_handler = handler;
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sa.sa_flags = SA_RESTART | SA_ONSTACK;
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sigfillset (&sa.sa_mask);
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if (sigaction (SIGUSR1, &sa, 0))
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FAIL_RET ("sigaction (SIGUSR1, handler): %m\n");
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raise (SIGUSR1);
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xfree_sigstack (sstk);
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FAIL_RET ("test process was not terminated by _exit in signal handler");
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}
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#include <support/test-driver.c>
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