diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/posix/system.c | 12 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/i386/system.c | 67 |
2 files changed, 79 insertions, 0 deletions
diff --git a/sysdeps/posix/system.c b/sysdeps/posix/system.c index bca1c2ec3e..08852801a6 100644 --- a/sysdeps/posix/system.c +++ b/sysdeps/posix/system.c @@ -112,7 +112,15 @@ do_system (const char *line) } } +#ifdef CLEANUP_HANDLER + CLEANUP_HANDLER; +#endif + +#ifdef FORK + pid = FORK (); +#else pid = __fork (); +#endif if (pid == (pid_t) 0) { /* Child side. */ @@ -158,6 +166,10 @@ do_system (const char *line) #endif } +#ifdef CLEANUP_HANDLER + CLEANUP_RESET; +#endif + save = errno; DO_LOCK (); if ((SUB_REF () == 0 diff --git a/sysdeps/unix/sysv/linux/i386/system.c b/sysdeps/unix/sysv/linux/i386/system.c new file mode 100644 index 0000000000..1107fd6668 --- /dev/null +++ b/sysdeps/unix/sysv/linux/i386/system.c @@ -0,0 +1,67 @@ +/* Copyright (C) 2002 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sched.h> +#include <signal.h> +#include <sysdep.h> +#include <unistd.h> +#include <sys/wait.h> +#include <bits/libc-lock.h> + +/* We have to and actually can handle cancelable system(). The big + problem: we have to kill the child process if necessary. To do + this a cleanup handler has to be registered and is has to be able + to find the PID of the child. The main problem is to reliable have + the PID when needed. It is not necessary for the parent thread to + return. It might still be in the kernel when the cancellation + request comes. Therefore we have to use the clone() calls ability + to have the kernel write the PID into the user-level variable. */ +#define FORK() \ + INLINE_SYSCALL (clone, 3, CLONE_PARENT_SETTID | SIGCHLD, 0, &pid) + +static void cancel_handler (void *arg); + +#define CLEANUP_HANDLER \ + __libc_cleanup_region_start (0, cancel_handler, &pid) + +#define CLEANUP_RESET \ + __libc_cleanup_region_end (0) + + +/* Linux has waitpid(), so override the generic unix version. */ +#include <sysdeps/posix/system.c> + + +/* The cancellation handler. */ +static void +cancel_handler (void *arg) +{ + __kill (SIGKILL, *(pid_t *) arg); + + TEMP_FAILURE_RETRY (waitpid (*(pid_t *) arg, NULL, 0)); + + DO_LOCK (); + + if (SUB_REF () == 0) + { + (void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL); + (void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL); + } + + DO_UNLOCK (); +} |