diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/posix/system.c | 72 |
1 files changed, 57 insertions, 15 deletions
diff --git a/sysdeps/posix/system.c b/sysdeps/posix/system.c index 6df7984889..0881a3a431 100644 --- a/sysdeps/posix/system.c +++ b/sysdeps/posix/system.c @@ -16,13 +16,14 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ +#include <errno.h> +#include <signal.h> #include <stddef.h> #include <stdlib.h> #include <unistd.h> -#include <sys/wait.h> -#include <signal.h> #include <sys/types.h> -#include <errno.h> +#include <sys/wait.h> +#include <bits/libc-lock.h> #ifndef HAVE_GNU_LD @@ -32,13 +33,36 @@ #define SHELL_PATH "/bin/sh" /* Path of the shell. */ #define SHELL_NAME "sh" /* Name to give it. */ + +#ifdef _LIBC_REENTRANT +static struct sigaction intr, quit; +static int sa_refcntr; +__libc_lock_define_initialized (static, lock); + +# define DO_LOCK() __libc_lock_lock (lock) +# define DO_UNLOCK() __libc_lock_unlock (lock) +# define INIT_LOCK() ({ __libc_lock_init (lock); sa_refcntr = 0; }) +# define ADD_REF() sa_refcntr++ +# define SUB_REF() --sa_refcntr +#else +# define DO_LOCK() +# define DO_UNLOCK() +# define INIT_LOCK() +# define ADD_REF() (void) 0 +# define SUB_REF() 0 +#endif + + /* Execute LINE as a shell command, returning its status. */ static int do_system (const char *line) { int status, save; pid_t pid; - struct sigaction sa, intr, quit; + struct sigaction sa; +#ifndef _LIBC_REENTRANT + struct sigaction intr, quit; +#endif #ifndef WAITPID_CANNOT_BLOCK_SIGCHLD sigset_t block, omask; #endif @@ -47,13 +71,22 @@ do_system (const char *line) sa.sa_flags = 0; __sigemptyset (&sa.sa_mask); - if (__sigaction (SIGINT, &sa, &intr) < 0) - return -1; - if (__sigaction (SIGQUIT, &sa, &quit) < 0) + DO_LOCK (); + if (ADD_REF () == 0) { - save = errno; - goto out_restore_sigint; + if (__sigaction (SIGINT, &sa, &intr) < 0) + { + SUB_REF (); + DO_UNLOCK (); + return -1; + } + if (__sigaction (SIGQUIT, &sa, &quit) < 0) + { + save = errno; + goto out_restore_sigint; + } } + DO_UNLOCK (); __sigemptyset (&block); __sigaddset (&block, SIGCHLD); @@ -65,9 +98,14 @@ do_system (const char *line) else { save = errno; - (void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL); + DO_LOCK (); + if (SUB_REF () == 0) + { + (void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL); out_restore_sigint: - (void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL); + (void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL); + } + DO_UNLOCK (); __set_errno (save); return -1; } @@ -87,6 +125,7 @@ do_system (const char *line) (void) __sigaction (SIGINT, &intr, (struct sigaction *) NULL); (void) __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL); (void) __sigprocmask (SIG_SETMASK, &omask, (sigset_t *) NULL); + INIT_LOCK (); /* Exec the shell. */ (void) __execve (SHELL_PATH, (char *const *) new_argv, __environ); @@ -119,9 +158,11 @@ do_system (const char *line) } save = errno; - if ((__sigaction (SIGINT, &intr, (struct sigaction *) NULL) - | __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL) - | __sigprocmask (SIG_SETMASK, &omask, (sigset_t *) NULL)) != 0) + DO_LOCK (); + if ((SUB_REF () == 0 + && (__sigaction (SIGINT, &intr, (struct sigaction *) NULL) + | __sigaction (SIGQUIT, &quit, (struct sigaction *) NULL)) != 0) + || __sigprocmask (SIG_SETMASK, &omask, (sigset_t *) NULL) != 0) { #ifndef _LIBC /* glibc cannot be used on systems without waitpid. */ @@ -129,8 +170,9 @@ do_system (const char *line) __set_errno (save); else #endif - return -1; + status = -1; } + DO_UNLOCK (); return status; } |