6282038 For csh, solaris 10 command form program>`program` never executes. cannot ctrl C out of it either

3 files changed, 125 insertions, 101 deletions

diff --git a/usr/src/cmd/csh/sh.proc.c b/usr/src/cmd/csh/sh.proc.c
index 195d2b07a1..2e4bfc4ea9 100644
--- a/usr/src/cmd/csh/sh.proc.c
+++ b/usr/src/cmd/csh/sh.proc.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -230,7 +230,29 @@ pjwait(pp)
 		while ((fp = (fp->p_friends)) != pp);
 		if ((jobflags & PRUNNING) == 0)
 			break;
-		sigpause(sigblock(0) &~ sigmask(SIGCHLD));
+		/*
+		 * At this point, csh used to call:
+		 *	sigpause(sigblock(0) &~ sigmask(SIGCHLD));
+		 * expecting to receive a SIGCHLD signal from the
+		 * termination of the child and to invoke the
+		 * signal handler, pchild(), as a result.
+		 *
+		 * However, vfork() now causes a vfork()'d child to
+		 * have all of its active signal handlers reset to
+		 * SIG_DFL, to forstall parent memory corruption due
+		 * to race conditions with signal handling.
+		 *
+		 * If this instance of csh is itself a child of vfork(),
+		 * which can happen when the top-level csh performs a
+		 * command substitution inside an i/o redirection, like:
+		 *	/bin/echo foo >`/bin/echo trash`
+		 * then we will never receive SIGCHLD.  To accommodate
+		 * this, we wait until one of our children terminates
+		 * (without actually reaping the child) and call the
+		 * SIGCHLD signal handler (pchild()) directly.
+		 */
+		if (csh_wait_noreap() > 0)
+			pchild();	/* simulate receipt of SIGCHLD */
 	}
 	(void) sigsetmask(omask);
 	if (tpgrp > 0)			/* get tty back */
diff --git a/usr/src/cmd/csh/wait.h b/usr/src/cmd/csh/wait.h
index 97b3579bc8..95260be9d9 100644
--- a/usr/src/cmd/csh/wait.h
+++ b/usr/src/cmd/csh/wait.h
@@ -1,6 +1,9 @@
 /*
- * Copyright 1994 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
+ */
+
+/*
  *
  *	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T
  *	  All Rights Reserved
@@ -22,9 +25,9 @@
  */
 
 #ifndef _sys_wait_h
-#define _sys_wait_h
+#define	_sys_wait_h
 
-#include <sys/isa_defs.h>	/* included for _LITTLE_ENDIAN define */
+#include <sys/isa_defs.h>	/* included for _LITTLE_ENDIAN define	*/
 
 /*
  * Structure of the information in the first word returned by both
@@ -69,14 +72,14 @@ union wait	{
 	} w_S;
 };
 #define	w_termsig	w_T.w_Termsig
-#define w_coredump	w_T.w_Coredump
-#define w_retcode	w_T.w_Retcode
-#define w_stopval	w_S.w_Stopval
-#define w_stopsig	w_S.w_Stopsig
+#define	w_coredump	w_T.w_Coredump
+#define	w_retcode	w_T.w_Retcode
+#define	w_stopval	w_S.w_Stopval
+#define	w_stopsig	w_S.w_Stopsig
 
 
 #define	WSTOPPED	0177	/* value of s.stopval if process is stopped */
-#define	WCONTFLG	0177777 /* value of w.w_status due to SIGCONT, sysV */
+#define	WCONTFLG	0177777	/* value of w.w_status due to SIGCONT, sysV */
 
 /*
  * Option bits for the second argument of wait3.  WNOHANG causes the
@@ -87,24 +90,14 @@ union wait	{
  * this option is done, it is as though they were still running... nothing
  * about them is returned.
  */
-#define WNOHANG		1	/* dont hang in wait */
-#define WUNTRACED	2	/* tell about stopped, untraced children */
+#define	WNOHANG		1	/* dont hang in wait */
+#define	WUNTRACED	2	/* tell about stopped, untraced children */
 
-#define WIFSTOPPED(x)	((x).w_stopval == WSTOPPED)
-#define WIFSIGNALED(x)	((x).w_stopval != WSTOPPED && (x).w_termsig != 0)
-#define WIFEXITED(x)	((x).w_stopval != WSTOPPED && (x).w_termsig == 0)
+#define	WIFSTOPPED(x)	((x).w_stopval == WSTOPPED)
+#define	WIFSIGNALED(x)	((x).w_stopval != WSTOPPED && (x).w_termsig != 0)
+#define	WIFEXITED(x)	((x).w_stopval != WSTOPPED && (x).w_termsig == 0)
 
-#ifdef KERNEL
-/* 
- * Arguments to wait4() system call, included here so it may be called by
- * other routines in the kernel 
- */
-struct wait4_args {
-	int pid;
-	union wait *status;
-	int options;
-	struct rusage *rusage;
-};
-#endif KERNEL
+extern pid_t csh_wait3(union wait *w, int options, struct rusage *rp);
+extern pid_t csh_wait_noreap(void);
 
-#endif /*!_sys_wait_h*/
+#endif /* _sys_wait_h */
diff --git a/usr/src/cmd/csh/wait3.c b/usr/src/cmd/csh/wait3.c
index b2ae68c95a..75c3ce366e 100644
--- a/usr/src/cmd/csh/wait3.c
+++ b/usr/src/cmd/csh/wait3.c
@@ -1,10 +1,10 @@
 /*
- * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
-/*	  All Rights Reserved  	*/
+/*	  All Rights Reserved	*/
 
 /*
  * Copyright (c) 1980 Regents of the University of California.
@@ -15,9 +15,9 @@
 #pragma ident	"%Z%%M%	%I%	%E% SMI"
 
 /*
- *      Compatibility lib for BSD's wait3(). It is not
- *      binary compatible, since BSD's WNOHANG and WUNTRACED
- *      carry different #define values.
+ * Compatibility lib for BSD's wait3(). It is not
+ * binary compatible, since BSD's WNOHANG and WUNTRACED
+ * carry different #define values.
  */
 #include <errno.h>
 #include <sys/types.h>
@@ -32,17 +32,17 @@
 /*
  * Since sysV does not support rusage as in BSD, an approximate approach
  * is:
- *      ...
- *      call times
- *      call waitid
- *      if ( a child is found )
- *              call times again
- *              rusage ~= diff in the 2 times call
- *      ...
- * 
+ *	...
+ *	call times
+ *	call waitid
+ *	if ( a child is found )
+ *		call times again
+ *		rusage ~= diff in the 2 times call
+ *	...
+ *
  */
 
-/* 
+/*
  * XXX:  There is now a wait3 function in libc which should be used instead
  * of this local version of wait3.  With the addition of a wait3 prototype
  * in <sys/wait.h> as per the X/Open XPG4v2 specification, compilation of
@@ -50,87 +50,96 @@
  * version.  Using the libc wait3 rather than the local version results in
  * a failure with csh, however, this version should eventually be dropped
  * in favor of the libc wait3 with appropriate updates made to sh.proc.c
- * to account for the difference in implementation of the local versus 
+ * to account for the difference in implementation of the local versus
  * the libc versions.  This should probably be done as part of an overall
  * effort to rid csh of local versions of functions now in libc.
  */
 
-csh_wait3(status, options, rp)
-        int	*status;
-        int     options;
-	struct	rusage	*rp;
- 
+static int wstat(int code, int status);
+
+pid_t
+csh_wait3(int *status, int options, struct rusage *rp)
 {
-        struct  tms     before_tms;
-        struct  tms     after_tms;
-        siginfo_t       info;
-        int             error;
+	struct tms before_tms;
+	struct tms after_tms;
+	siginfo_t info;
+	int error;
 
 	if (rp)
-		memset((void *)rp, 0, sizeof(struct rusage));
-	memset((void *)&info, 0, sizeof(siginfo_t));
-        if ( times(&before_tms) == -1 ) 
-                return (-1);            /* errno is set by times() */
+		memset((void *)rp, 0, sizeof (struct rusage));
+	memset((void *)&info, 0, sizeof (siginfo_t));
+	if (times(&before_tms) == -1)
+		return (-1);	/* errno is set by times() */
 
 	/*
 	 * BSD's wait3() only supports WNOHANG & WUNTRACED
 	 */
 	options |= (WNOHANG|WUNTRACED|WEXITED|WSTOPPED|WTRAPPED|WCONTINUED);
-        error = waitid(P_ALL, 0, &info, options);
-        if ( error == 0 ) {
-                clock_t	diffu;  /* difference in usertime (ticks) */
-                clock_t	diffs;  /* difference in systemtime (ticks) */
+	error = waitid(P_ALL, 0, &info, options);
+	if (error == 0) {
+		clock_t	diffu;	/* difference in usertime (ticks) */
+		clock_t	diffs;	/* difference in systemtime (ticks) */
 
-                if ( (options & WNOHANG) && (info.si_pid == 0) )
-                        return (0);     /* no child found */
+		if ((options & WNOHANG) && (info.si_pid == 0))
+			return (0);	/* no child found */
 
 		if (rp) {
-                	if ( times(&after_tms) == -1 )
-                        	return (-1);    /* errno set by times() */
-                	/*
-                 	 * The system/user time is an approximation only !!!
-                 	 */
-                	diffu = after_tms.tms_cutime - before_tms.tms_cutime;
-                	diffs = after_tms.tms_cstime - before_tms.tms_cstime;
-                	rp->ru_utime.tv_sec = diffu/HZ;
-                	rp->ru_utime.tv_usec = (diffu % HZ) / HZ * 1000000;
-                	rp->ru_stime.tv_sec = diffs/HZ;
-                	rp->ru_stime.tv_usec = (diffs % HZ) / HZ * 1000000;
+			if (times(&after_tms) == -1)
+				return (-1);	/* errno set by times() */
+			/*
+			 * The system/user time is an approximation only !!!
+			 */
+			diffu = after_tms.tms_cutime - before_tms.tms_cutime;
+			diffs = after_tms.tms_cstime - before_tms.tms_cstime;
+			rp->ru_utime.tv_sec = diffu/HZ;
+			rp->ru_utime.tv_usec = (diffu % HZ) / HZ * 1000000;
+			rp->ru_stime.tv_sec = diffs/HZ;
+			rp->ru_stime.tv_usec = (diffs % HZ) / HZ * 1000000;
 		}
-               	*status = wstat(info.si_code, info.si_status);
-                return (info.si_pid);
+		*status = wstat(info.si_code, info.si_status);
+		return (info.si_pid);
 
-        } else {
-                return (-1);            /* error number is set by waitid() */
-        }
+	} else {
+		return (-1);	/* error number is set by waitid() */
+	}
 }
 
 /*
  * Convert the status code to old style wait status
  */
-wstat(code, status)
-        int     code;
-        int     status;
+static int
+wstat(int code, int status)
 {
-        register stat = (status & 0377);
-
-        switch (code) {
-                case CLD_EXITED:
-                        stat <<= 8;
-                        break;
-                case CLD_DUMPED:
-                        stat |= WCOREFLG;
-                        break;
-                case CLD_KILLED:
-                        break;
-                case CLD_TRAPPED:
-                case CLD_STOPPED:
-                        stat <<= 8;
-                        stat |= WSTOPFLG;
-                        break;
+	int stat = (status & 0377);
+
+	switch (code) {
+		case CLD_EXITED:
+			stat <<= 8;
+			break;
+		case CLD_DUMPED:
+			stat |= WCOREFLG;
+			break;
+		case CLD_KILLED:
+			break;
+		case CLD_TRAPPED:
+		case CLD_STOPPED:
+			stat <<= 8;
+			stat |= WSTOPFLG;
+			break;
 		case CLD_CONTINUED:
-                        stat = WCONTFLG;
-                        break;
-        }
-        return (stat);
+			stat = WCONTFLG;
+			break;
+	}
+	return (stat);
+}
+
+pid_t
+csh_wait_noreap(void)
+{
+	siginfo_t info;
+
+	if (waitid(P_ALL, 0, &info,
+	    WEXITED | WTRAPPED | WSTOPPED | WCONTINUED | WNOWAIT) != 0)
+		return (-1);
+	return (info.si_pid);
 }