diff options
Diffstat (limited to 'stdlib/tst-sigcontext.c')
| -rw-r--r-- | stdlib/tst-sigcontext.c | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/stdlib/tst-sigcontext.c b/stdlib/tst-sigcontext.c new file mode 100644 index 0000000000..45b1a06a28 --- /dev/null +++ b/stdlib/tst-sigcontext.c @@ -0,0 +1,312 @@ +/* Copyright (C) 2009 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Maciej W. Rozycki <macro@codesourcery.com>. + + 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, write to the Free + Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA + 02110-1301, USA. */ + +#include <errno.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <ucontext.h> +#include <unistd.h> + +static volatile ucontext_t ctx[3]; +static volatile int flags[3]; +static volatile int oflag; +static volatile int flag; + +static volatile int sig_errno_set; +static volatile int sig_errno; +static volatile int sig_ready; + +static int was_in_f1; +static int was_in_f2; + +static char st2[32768]; + +static long long int max; +static volatile long long int count; + +/* These have to be run with the caller's frame. */ +static inline int sig_getcontext (int) __attribute__ ((always_inline)); +static inline int sig_swapcontext (int, int) __attribute__ ((always_inline)); + +static void +sig_gethandler (int signo, siginfo_t *info, void *context) +{ + ucontext_t *ucp = context; + + if (! sig_ready) + { + alarm (1); + return; + } + + ctx[flag] = *ucp; + flags[flag] = 1; + + sig_errno_set = 1; + sig_errno = 0; +} + +static void +sig_swaphandler (int signo, siginfo_t *info, void *context) +{ + ucontext_t *oucp = context; + ucontext_t *ucp = (ucontext_t *) (ctx + flag); + + if (! sig_ready) + { + alarm (1); + return; + } + + ctx[oflag] = *oucp; + flags[oflag] = 1; + + sig_errno_set = 1; + sig_errno = setcontext (ucp); +} + +static int +sig_getcontext (int uci) +{ + struct sigaction sa; + + sigemptyset (&sa.sa_mask); + sa.sa_flags = SA_SIGINFO; + sa.sa_sigaction = sig_gethandler; + if (sigaction (SIGALRM, &sa, NULL) < 0) + { + printf ("%s: sigaction ALRM failed: %m\n", __FUNCTION__); + exit (1); + } + + flag = uci; + sig_errno_set = 0; + sig_ready = 0; + alarm (1); + + /* Need to get the signal in this frame. */ + sig_ready = 1; + for (count = max; count > 0; count--) + if (sig_errno_set) + break; + + if (! sig_errno_set) + { + printf ("%s: ALRM signal not received\n", __FUNCTION__); + exit (1); + } + + return 0; +} + +static int +sig_swapcontext (int ouci, int uci) +{ + struct sigaction sa; + + sigemptyset (&sa.sa_mask); + sa.sa_flags = SA_SIGINFO; + sa.sa_sigaction = sig_swaphandler; + if (sigaction (SIGALRM, &sa, NULL) < 0) + { + printf ("%s: sigaction ALRM failed: %m\n", __FUNCTION__); + exit (1); + } + + flag = uci; + oflag = ouci; + sig_errno_set = 0; + sig_ready = 0; + alarm (1); + + /* Need to get the signal in this frame. */ + sig_ready = 1; + for (count = max; count > 0; count--) + if (sig_errno_set) + break; + + if (! sig_errno_set) + { + printf ("%s: ALRM signal not received\n", __FUNCTION__); + exit (1); + } + + return sig_errno; +} + + +static void +f1 (int a0, int a1, int a2, int a3) +{ + int status; + + printf ("start f1(a0=%x,a1=%x,a2=%x,a3=%x)\n", a0, a1, a2, a3); + + if (a0 != 1 || a1 != 2 || a2 != 3 || a3 != -4) + { + puts ("arg mismatch"); + exit (-1); + } + + status = sig_swapcontext (1, 2); + if (status != 0) + { + printf ("%s: swapping contexts failed: %s\n", + __FUNCTION__, strerror (status)); + exit (1); + } + puts ("finish f1"); + was_in_f1 = 1; +} + +static void +f2 (void) +{ + int status; + + puts ("start f2"); + + status = sig_swapcontext (2, 1); + if (status != 0) + { + printf ("%s: swapping contexts failed: %s\n", + __FUNCTION__, strerror (status)); + exit (1); + } + puts ("finish f2"); + was_in_f2 = 1; +} + + +static int back_in_main; + +static void +check_called (void) +{ + if (back_in_main == 0) + { + printf ("%s: program did not reach main again", __FUNCTION__); + _exit (1); + } +} + + +volatile int global; + +int +main (void) +{ + char st1[32768]; + time_t t0, t1; + int status; + + atexit (check_called); + + puts ("calibrating delay loop"); + for (max = 0x10000; max < LLONG_MAX / 2; max *= 2) + { + t0 = time (NULL); + for (count = max; count > 0; count--); + t1 = time (NULL); + if (difftime (t1, t0) > 10.0) + break; + } + + puts ("making contexts"); + + sig_getcontext (1); + if (! flags[1]) + { + printf ("%s: context not retrieved\n", __FUNCTION__); + exit (1); + } + + /* Play some tricks with this context. */ + if (++global == 1) + if (setcontext ((ucontext_t *) &ctx[1]) != 0) + { + if (errno == ENOSYS) + { + back_in_main = 1; + exit (0); + } + printf ("%s: setcontext: %m\n", __FUNCTION__); + exit (1); + } + if (global != 2) + { + printf ("%s: 'global' not incremented twice\n", __FUNCTION__); + exit (1); + } + + ctx[1].uc_stack.ss_sp = st1; + ctx[1].uc_stack.ss_size = sizeof st1; + ctx[1].uc_link = (ucontext_t *) &ctx[0]; + { + ucontext_t tempctx = ctx[1]; + makecontext ((ucontext_t *) &ctx[1], (void (*) (void)) f1, 4, 1, 2, 3, -4); + + /* Without this check, a stub makecontext can make us spin forever. */ + if (memcmp (&tempctx, (void *) &ctx[1], sizeof ctx[1]) == 0) + { + puts ("makecontext was a no-op, presuming not implemented"); + return 0; + } + } + + sig_getcontext (2); + if (! flags[2]) + { + printf ("%s: second context not retrieved\n", __FUNCTION__); + exit (1); + } + + ctx[2].uc_stack.ss_sp = st2; + ctx[2].uc_stack.ss_size = sizeof st2; + ctx[2].uc_link = (ucontext_t *) &ctx[1]; + makecontext ((ucontext_t *) &ctx[2], f2, 0); + + puts ("swapping contexts"); + status = sig_swapcontext (0, 2); + if (status != 0) + { + printf ("%s: swapping contexts failed: %s\n", + __FUNCTION__, strerror (status)); + exit (1); + } + puts ("back at main program"); + back_in_main = 1; + + if (was_in_f1 == 0) + { + puts ("didn't reach f1"); + exit (1); + } + if (was_in_f2 == 0) + { + puts ("didn't reach f2"); + exit (1); + } + + puts ("test succeeded"); + return 0; +} |