Don't acquire __environ_lock around exec*() calls; nothing requires
that these calls be thread-safe with respect to the environment, and it causes serious problems for threaded applications which call vfork() and exec*() (including indirectly, via popen() or system()). Acquire and release __environ_lock in the parent in popen() and system() to play safe and provide the child with a stable environment. __environ_lock should also have an atfork() handler; still under development.
This commit is contained in:
nathanw
parent
2ea5d53fe3
commit
f60f35f3ab
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@ -1,4 +1,4 @@
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/* $NetBSD: execl.c,v 1.9 2003/01/18 11:23:53 thorpej Exp $ */
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/* $NetBSD: execl.c,v 1.10 2003/03/04 19:44:09 nathanw Exp $ */
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/*-
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* Copyright (c) 1991, 1993
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@ -38,7 +38,7 @@
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#if 0
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static char sccsid[] = "@(#)exec.c 8.1 (Berkeley) 6/4/93";
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#else
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__RCSID("$NetBSD: execl.c,v 1.9 2003/01/18 11:23:53 thorpej Exp $");
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__RCSID("$NetBSD: execl.c,v 1.10 2003/03/04 19:44:09 nathanw Exp $");
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#endif
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#endif /* LIBC_SCCS and not lint */
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@ -54,18 +54,13 @@ __weak_alias(execl,_execl)
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extern char **environ;
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#ifdef _REENTRANT
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extern rwlock_t __environ_lock;
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#endif
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int
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execl(const char *name, const char *arg, ...)
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{
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int r;
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#if defined(__i386__) || defined(__m68k__) || defined(__ns32k__)
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rwlock_rdlock(&__environ_lock);
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r = execve(name, (char **) &arg, environ);
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rwlock_unlock(&__environ_lock);
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return (r);
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#else
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va_list ap;
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@ -85,9 +80,7 @@ execl(const char *name, const char *arg, ...)
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;
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va_end(ap);
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rwlock_rdlock(&__environ_lock);
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r = execve(name, argv, environ);
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rwlock_unlock(&__environ_lock);
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return (r);
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#endif
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}
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@ -1,4 +1,4 @@
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/* $NetBSD: execv.c,v 1.6 2003/01/18 11:23:53 thorpej Exp $ */
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/* $NetBSD: execv.c,v 1.7 2003/03/04 19:44:09 nathanw Exp $ */
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/*-
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* Copyright (c) 1991, 1993
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@ -38,7 +38,7 @@
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#if 0
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static char sccsid[] = "@(#)exec.c 8.1 (Berkeley) 6/4/93";
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#else
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__RCSID("$NetBSD: execv.c,v 1.6 2003/01/18 11:23:53 thorpej Exp $");
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__RCSID("$NetBSD: execv.c,v 1.7 2003/03/04 19:44:09 nathanw Exp $");
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#endif
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#endif /* LIBC_SCCS and not lint */
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@ -51,9 +51,6 @@ __weak_alias(execv,_execv)
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#endif
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extern char **environ;
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#ifdef _REENTRANT
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extern rwlock_t __environ_lock;
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#endif
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int
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execv(name, argv)
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@ -62,8 +59,6 @@ execv(name, argv)
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{
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int r;
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rwlock_rdlock(&__environ_lock);
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r = execve(name, argv, environ);
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rwlock_unlock(&__environ_lock);
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return (r);
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}
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@ -1,4 +1,4 @@
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/* $NetBSD: execvp.c,v 1.21 2003/01/18 11:23:53 thorpej Exp $ */
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/* $NetBSD: execvp.c,v 1.22 2003/03/04 19:44:10 nathanw Exp $ */
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/*-
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* Copyright (c) 1991, 1993
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@ -38,7 +38,7 @@
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#if 0
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static char sccsid[] = "@(#)exec.c 8.1 (Berkeley) 6/4/93";
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#else
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__RCSID("$NetBSD: execvp.c,v 1.21 2003/01/18 11:23:53 thorpej Exp $");
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__RCSID("$NetBSD: execvp.c,v 1.22 2003/03/04 19:44:10 nathanw Exp $");
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#endif
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#endif /* LIBC_SCCS and not lint */
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@ -58,9 +58,6 @@ __weak_alias(execvp,_execvp)
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#endif
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extern char **environ;
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#ifdef _REENTRANT
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extern rwlock_t __environ_lock;
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#endif
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int
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execvp(const char *name, char * const *argv)
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@ -123,9 +120,7 @@ execvp(const char *name, char * const *argv)
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memcpy(buf + lp + 1, name, ln);
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buf[lp + ln + 1] = '\0';
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retry: rwlock_rdlock(&__environ_lock);
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(void)execve(bp, argv, environ);
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rwlock_unlock(&__environ_lock);
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retry: (void)execve(bp, argv, environ);
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switch (errno) {
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case EACCES:
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eacces = 1;
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@ -140,10 +135,8 @@ retry: rwlock_rdlock(&__environ_lock);
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memp[0] = _PATH_BSHELL;
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memp[1] = bp;
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(void)memcpy(&memp[2], &argv[1], cnt * sizeof(*memp));
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rwlock_rdlock(&__environ_lock);
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(void)execve(_PATH_BSHELL, (char * const *)memp,
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environ);
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rwlock_unlock(&__environ_lock);
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goto done;
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case ETXTBSY:
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if (etxtbsy < 3)
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@ -1,4 +1,4 @@
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/* $NetBSD: popen.c,v 1.25 2000/01/22 22:19:11 mycroft Exp $ */
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/* $NetBSD: popen.c,v 1.26 2003/03/04 19:44:10 nathanw Exp $ */
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/*
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* Copyright (c) 1988, 1993
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@ -41,7 +41,7 @@
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#if 0
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static char sccsid[] = "@(#)popen.c 8.3 (Berkeley) 5/3/95";
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#else
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__RCSID("$NetBSD: popen.c,v 1.25 2000/01/22 22:19:11 mycroft Exp $");
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__RCSID("$NetBSD: popen.c,v 1.26 2003/03/04 19:44:10 nathanw Exp $");
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#endif
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#endif /* LIBC_SCCS and not lint */
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@ -58,12 +58,17 @@ __RCSID("$NetBSD: popen.c,v 1.25 2000/01/22 22:19:11 mycroft Exp $");
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "reentrant.h"
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#ifdef __weak_alias
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__weak_alias(popen,_popen)
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__weak_alias(pclose,_pclose)
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#endif
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#ifdef _REENTRANT
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extern rwlock_t __environ_lock;
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#endif
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static struct pid {
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struct pid *next;
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FILE *fp;
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return (NULL);
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}
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rwlock_rdlock(&__environ_lock);
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switch (pid = vfork()) {
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case -1: /* Error. */
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serrno = errno;
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rwlock_unlock(&__environ_lock);
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free(cur);
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(void)close(pdes[0]);
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(void)close(pdes[1]);
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_exit(127);
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/* NOTREACHED */
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}
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rwlock_unlock(&__environ_lock);
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/* Parent; assume fdopen can't fail. */
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if (*type == 'r') {
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@ -1,4 +1,4 @@
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/* $NetBSD: system.c,v 1.17 2001/10/31 13:31:26 kleink Exp $ */
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/* $NetBSD: system.c,v 1.18 2003/03/04 19:44:10 nathanw Exp $ */
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/*
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* Copyright (c) 1988, 1993
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@ -38,7 +38,7 @@
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#if 0
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static char sccsid[] = "@(#)system.c 8.1 (Berkeley) 6/4/93";
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#else
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__RCSID("$NetBSD: system.c,v 1.17 2001/10/31 13:31:26 kleink Exp $");
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__RCSID("$NetBSD: system.c,v 1.18 2003/03/04 19:44:10 nathanw Exp $");
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#endif
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#endif /* LIBC_SCCS and not lint */
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@ -50,7 +50,11 @@ __RCSID("$NetBSD: system.c,v 1.17 2001/10/31 13:31:26 kleink Exp $");
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#include <stdlib.h>
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#include <unistd.h>
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#include <paths.h>
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#include "reentrant.h"
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#ifdef _REENTRANT
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extern rwlock_t __environ_lock;
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#endif
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extern char **environ;
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int
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@ -80,8 +84,10 @@ system(command)
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if (sigprocmask(SIG_BLOCK, &nmask, &omask) == -1)
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return -1;
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rwlock_rdlock(&__environ_lock);
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switch(pid = vfork()) {
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case -1: /* error */
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rwlock_unlock(&__environ_lock);
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sigaction(SIGINT, &intsa, NULL);
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sigaction(SIGQUIT, &quitsa, NULL);
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(void)sigprocmask(SIG_SETMASK, &omask, NULL);
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execve(_PATH_BSHELL, argp, environ);
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_exit(127);
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}
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rwlock_unlock(&__environ_lock);
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while (waitpid(pid, &pstat, 0) == -1) {
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if (errno != EINTR) {
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