diff options
Diffstat (limited to 'signal')
| -rw-r--r-- | signal/Makefile | 2 | ||||
| -rw-r--r-- | signal/tst-minsigstksz-1.c | 131 | ||||
| -rw-r--r-- | signal/tst-minsigstksz-2.c | 66 | ||||
| -rw-r--r-- | signal/tst-minsigstksz-3.c | 64 | ||||
| -rw-r--r-- | signal/tst-minsigstksz-3a.c | 69 | ||||
| -rw-r--r-- | signal/tst-minsigstksz-4.c | 65 |
6 files changed, 397 insertions, 0 deletions
diff --git a/signal/Makefile b/signal/Makefile index 647ce242e6..9597287bca 100644 --- a/signal/Makefile +++ b/signal/Makefile @@ -47,6 +47,8 @@ routines := signal raise killpg \ tests := tst-signal tst-sigset tst-sigsimple tst-raise tst-sigset2 \ tst-sigwait-eintr tst-sigaction \ + tst-minsigstksz-1 tst-minsigstksz-2 tst-minsigstksz-3 \ + tst-minsigstksz-3a tst-minsigstksz-4 \ include ../Rules diff --git a/signal/tst-minsigstksz-1.c b/signal/tst-minsigstksz-1.c new file mode 100644 index 0000000000..00344d5fbf --- /dev/null +++ b/signal/tst-minsigstksz-1.c @@ -0,0 +1,131 @@ +/* Tests of signal delivery on an alternate stack (nonlethal). + 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/check.h> + +/* C2011 7.4.1.1p5 specifies that only the following operations are + guaranteed to be well-defined inside an asynchronous signal handler: + * any operation on a lock-free atomic object + * assigning a value to an object declared as volatile sig_atomic_t + * calling abort, _Exit, quick_exit, or signal + * signal may only be called with its first argument equal to the + number of the signal that caused the handler to be called + + We use this list as a guideline for the set of operations that ought + also to be safe in a _synchronous_ signal delivered on an alternate + signal stack with only MINSIGSTKSZ bytes of space. + + This test program tests all of the above operations that do not, + one way or another, cause the program to be terminated. */ + +/* We do not try to test atomic operations exhaustively, only a simple + atomic counter increment. This is only safe if atomic_[u]int is + unconditionally lock-free. */ +#ifdef __STDC_NO_ATOMICS__ +# define TEST_ATOMIC_OPS 0 +#else +# include <stdatomic.h> +# if ATOMIC_INT_LOCK_FREE != 2 +# define TEST_ATOMIC_OPS 0 +# else +# define TEST_ATOMIC_OPS 1 +# endif +#endif + +static volatile sig_atomic_t signal_flag = 0; +static volatile sig_atomic_t signal_err = 0; +static void +handler_set_flag (int unused) +{ + signal_flag = 1; +} + +static void +handler_set_flag_once (int sig) +{ + signal_flag = 1; + if (signal (sig, SIG_IGN) == SIG_ERR) + /* It is not safe to call FAIL_EXIT1 here. Set another flag instead. */ + signal_err = 1; +} + +#if TEST_ATOMIC_OPS +static atomic_uint signal_count = 0; +static void +handler_count_up_1 (int unused) +{ + atomic_fetch_add (&signal_count, 1); +} +#endif + +int +do_test (void) +{ + void *sstk = xalloc_sigstack (0); + struct sigaction sa; + + /* Test 1: setting a volatile sig_atomic_t flag. */ + sa.sa_handler = handler_set_flag; + sa.sa_flags = SA_RESTART | SA_ONSTACK; + sigfillset (&sa.sa_mask); + if (sigaction (SIGUSR1, &sa, 0)) + FAIL_EXIT1 ("sigaction (SIGUSR1, handler_set_flag): %m\n"); + + TEST_VERIFY_EXIT (signal_flag == 0); + raise (SIGUSR1); + TEST_VERIFY_EXIT (signal_flag == 1); + signal_flag = 0; + raise (SIGUSR1); + TEST_VERIFY_EXIT (signal_flag == 1); + signal_flag = 0; + + /* Test 1: setting a volatile sig_atomic_t flag and then ignoring + further delivery of the signal. */ + sa.sa_handler = handler_set_flag_once; + if (sigaction (SIGUSR1, &sa, 0)) + FAIL_EXIT1 ("sigaction (SIGUSR1, handler_set_flag_once): %m\n"); + + raise (SIGUSR1); + TEST_VERIFY_EXIT (signal_flag == 1); + /* Note: if signal_err is 1, a system call failed, but we can't + report the error code because errno is indeterminate. */ + TEST_VERIFY_EXIT (signal_err == 0); + + signal_flag = 0; + raise (SIGUSR1); + TEST_VERIFY_EXIT (signal_flag == 0); + TEST_VERIFY_EXIT (signal_err == 0); + +#if TEST_ATOMIC_OPS + sa.sa_handler = handler_count_up_1; + if (sigaction (SIGUSR1, &sa, 0)) + FAIL_EXIT1 ("sigaction (SIGUSR1, handler_count_up_1): %m\n"); + + raise (SIGUSR1); + TEST_VERIFY_EXIT (atomic_load (&signal_count) == 1); + raise (SIGUSR1); + TEST_VERIFY_EXIT (atomic_load (&signal_count) == 2); +#endif + + xfree_sigstack (sstk); + return 0; +} + +#include <support/test-driver.c> diff --git a/signal/tst-minsigstksz-2.c b/signal/tst-minsigstksz-2.c new file mode 100644 index 0000000000..3368dde6b8 --- /dev/null +++ b/signal/tst-minsigstksz-2.c @@ -0,0 +1,66 @@ +/* Tests of signal delivery on an alternate stack (abort). + 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/check.h> +#include <stdlib.h> + +/* C2011 7.4.1.1p5 specifies that only the following operations are + guaranteed to be well-defined inside an asynchronous signal handler: + * any operation on a lock-free atomic object + * assigning a value to an object declared as volatile sig_atomic_t + * calling abort, _Exit, quick_exit, or signal + * signal may only be called with its first argument equal to the + number of the signal that caused the handler to be called + + We use this list as a guideline for the set of operations that ought + also to be safe in a _synchronous_ signal delivered on an alternate + signal stack with only MINSIGSTKSZ bytes of space. + + This test program tests calls to abort. Note that it does _not_ + install a handler for SIGABRT, because that signal would also be + delivered on the alternate stack and MINSIGSTKSZ does not provide + enough space for delivery of nested signals. */ + +static void +handler (int unused) +{ + abort (); +} + +int +do_test (void) +{ + void *sstk = xalloc_sigstack (0); + 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); + + xfree_sigstack (sstk); + FAIL_RET ("test process was not terminated by abort in signal handler"); +} + +#define EXPECTED_SIGNAL SIGABRT +#include <support/test-driver.c> diff --git a/signal/tst-minsigstksz-3.c b/signal/tst-minsigstksz-3.c new file mode 100644 index 0000000000..a8d9a6369c --- /dev/null +++ b/signal/tst-minsigstksz-3.c @@ -0,0 +1,64 @@ +/* Tests of signal delivery on an alternate stack (_Exit). + 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/check.h> +#include <stdlib.h> + +/* C2011 7.4.1.1p5 specifies that only the following operations are + guaranteed to be well-defined inside an asynchronous signal handler: + * any operation on a lock-free atomic object + * assigning a value to an object declared as volatile sig_atomic_t + * calling abort, _Exit, quick_exit, or signal + * signal may only be called with its first argument equal to the + number of the signal that caused the handler to be called + + We use this list as a guideline for the set of operations that ought + also to be safe in a _synchronous_ signal delivered on an alternate + signal stack with only MINSIGSTKSZ bytes of space. + + This test program tests calls to _Exit. */ + +#define EXPECTED_STATUS 3 + +static void +handler (int unused) +{ + _Exit (EXPECTED_STATUS); +} + +int +do_test (void) +{ + void *sstk = xalloc_sigstack (0); + 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); + + xfree_sigstack (sstk); + FAIL_RET ("test process was not terminated by _Exit in signal handler"); +} + +#include <support/test-driver.c> diff --git a/signal/tst-minsigstksz-3a.c b/signal/tst-minsigstksz-3a.c new file mode 100644 index 0000000000..b58b8d01ba --- /dev/null +++ b/signal/tst-minsigstksz-3a.c @@ -0,0 +1,69 @@ +/* Tests of signal delivery on an alternate stack (_exit). + 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/check.h> +#include <unistd.h> + +/* C2011 7.4.1.1p5 specifies that only the following operations are + guaranteed to be well-defined inside an asynchronous signal handler: + * any operation on a lock-free atomic object + * assigning a value to an object declared as volatile sig_atomic_t + * calling abort, _Exit, quick_exit, or signal + * signal may only be called with its first argument equal to the + number of the signal that caused the handler to be called + + We use this list as a guideline for the set of operations that ought + also to be safe in a _synchronous_ signal delivered on an alternate + signal stack with only MINSIGSTKSZ bytes of space. + + This test program tests calls to _exit, which is the same function + as _Exit, but specified by POSIX rather than ISO C. For reasons + unknown to the author of this program, the C committee did not + think it could standardize _exit under that name; regardless, in a + POSIX-conformant environment, they should be completely + interchangeable. */ + +#define EXPECTED_STATUS 3 + +static void +handler (int unused) +{ + _exit (EXPECTED_STATUS); +} + +int +do_test (void) +{ + void *sstk = xalloc_sigstack (0); + 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); + + xfree_sigstack (sstk); + FAIL_RET ("test process was not terminated by _exit in signal handler"); +} + +#include <support/test-driver.c> diff --git a/signal/tst-minsigstksz-4.c b/signal/tst-minsigstksz-4.c new file mode 100644 index 0000000000..0dc63b4dd4 --- /dev/null +++ b/signal/tst-minsigstksz-4.c @@ -0,0 +1,65 @@ +/* Tests of signal delivery on an alternate stack (quick_exit). + 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/check.h> +#include <stdlib.h> + +/* C2011 7.4.1.1p5 specifies that only the following operations are + guaranteed to be well-defined inside an asynchronous signal handler: + * any operation on a lock-free atomic object + * assigning a value to an object declared as volatile sig_atomic_t + * calling abort, _Exit, quick_exit, or signal + * signal may only be called with its first argument equal to the + number of the signal that caused the handler to be called + + We use this list as a guideline for the set of operations that ought + also to be safe in a _synchronous_ signal delivered on an alternate + signal stack with only MINSIGSTKSZ bytes of space. + + This test program tests calls to quick_exit. Note that this is only + safe when there are no at_quick_exit callbacks. */ + +#define EXPECTED_STATUS 3 + +static void +handler (int unused) +{ + quick_exit (EXPECTED_STATUS); +} + +int +do_test (void) +{ + void *sstk = xalloc_sigstack (0); + 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); + + xfree_sigstack (sstk); + FAIL_RET ("test process was not terminated by quick_exit in signal handler"); +} + +#include <support/test-driver.c> |