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fix wait

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This commit is contained in:
rsc 2007-03-26 14:26:32 +00:00
parent bd1b0cc17e
commit 4b241872ef
5 changed files with 97 additions and 251 deletions
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51
src/cmd/rc/havefork.c
View file

@ -1,3 +1,9 @@
#include <u.h>
#include <signal.h>
#if defined(PLAN9PORT) && defined(__sun__)
# define BSD_COMP /* sigh. for TIOCNOTTY */
#endif
#include <sys/ioctl.h>
#include "rc.h"
#include "getflags.h"
#include "exec.h"
@ -10,6 +16,7 @@ void
Xasync(void)
{
int null = open("/dev/null", 0);
int tty;
int pid;
char npid[10];
if(null<0){
@ -22,11 +29,39 @@ Xasync(void)
Xerror("try again");
break;
case 0:
pushredir(ROPEN, null, 0);
clearwaitpids();
/*
* I don't know what the right thing to do here is,
* so this is all experimentally determined.
* If we just dup /dev/null onto 0, then running
* ssh foo & will reopen /dev/tty, try to read a password,
* get a signal, and repeat, in a tight loop, forever.
* Arguably this is a bug in ssh (it behaves the same
* way under bash as under rc) but I'm fixing it here
* anyway. If we dissociate the process from the tty,
* then it won't be able to open /dev/tty ever again.
* The SIG_IGN on SIGTTOU makes writing the tty
* (via fd 1 or 2, for example) succeed even though
* our pgrp is not the terminal's controlling pgrp.
*/
if((tty = open("/dev/tty", OREAD)) >= 0){
/*
* Should make reads of tty fail, writes succeed.
*/
signal(SIGTTIN, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
ioctl(tty, TIOCNOTTY);
close(tty);
}
if(isatty(0))
pushredir(ROPEN, null, 0);
else
close(null);
start(runq->code, runq->pc+1, runq->local);
runq->ret = 0;
break;
default:
addwaitpid(pid);
close(null);
runq->pc = runq->code[runq->pc].i;
inttoascii(npid, pid);
@ -52,12 +87,14 @@ Xpipe(void)
Xerror("try again");
break;
case 0:
clearwaitpids();
start(p->code, pc+2, runq->local);
runq->ret = 0;
close(pfd[PRD]);
pushredir(ROPEN, pfd[PWR], lfd);
break;
default:
addwaitpid(forkid);
start(p->code, p->code[pc].i, runq->local);
close(pfd[PWR]);
pushredir(ROPEN, pfd[PRD], rfd);
@ -93,11 +130,13 @@ Xbackq(void)
close(pfd[PWR]);
return;
case 0:
clearwaitpids();
close(pfd[PRD]);
start(runq->code, runq->pc+1, runq->local);
pushredir(ROPEN, pfd[PWR], 1);
return;
default:
addwaitpid(pid);
close(pfd[PWR]);
f = openfd(pfd[PRD]);
s = wd;
@ -134,7 +173,7 @@ void
Xpipefd(void)
{
struct thread *p = runq;
int pc = p->pc;
int pc = p->pc, pid;
char name[40];
int pfd[2];
int sidefd, mainfd;
@ -150,17 +189,19 @@ Xpipefd(void)
sidefd = pfd[PRD];
mainfd = pfd[PWR];
}
switch(fork()){
switch(pid = fork()){
case -1:
Xerror("try again");
break;
case 0:
clearwaitpids();
start(p->code, pc+2, runq->local);
close(mainfd);
pushredir(ROPEN, sidefd, p->code[pc].i==READ?1:0);
runq->ret = 0;
break;
default:
addwaitpid(pid);
close(sidefd);
pushredir(ROPEN, mainfd, mainfd); /* isn't this a noop? */
strcpy(name, Fdprefix);
@ -180,10 +221,12 @@ Xsubshell(void)
Xerror("try again");
break;
case 0:
clearwaitpids();
start(runq->code, runq->pc+1, runq->local);
runq->ret = 0;
break;
default:
addwaitpid(pid);
Waitfor(pid, 1);
runq->pc = runq->code[runq->pc].i;
break;
@ -201,6 +244,7 @@ execforkexec(void)
case -1:
return -1;
case 0:
clearwaitpids();
pushword("exec");
execexec();
strcpy(buf, "can't exec: ");
@ -208,5 +252,6 @@ execforkexec(void)
errstr(buf+n, ERRMAX-n);
Exit(buf);
}
addwaitpid(pid);
return pid;
}