diff options
Diffstat (limited to 'src/cmd/rc/exec.c')
| -rw-r--r-- | src/cmd/rc/exec.c | 32 |
1 files changed, 31 insertions, 1 deletions
diff --git a/src/cmd/rc/exec.c b/src/cmd/rc/exec.c index fc7b630b..e6cde9e1 100644 --- a/src/cmd/rc/exec.c +++ b/src/cmd/rc/exec.c @@ -1,3 +1,6 @@ +#include <u.h> +#include <signal.h> +#include <sys/ioctl.h> #include "rc.h" #include "getflags.h" #include "exec.h" @@ -220,6 +223,7 @@ void Xappend(void){ } void Xasync(void){ int null=open("/dev/null", 0); + int tty; int pid; char npid[10]; if(null<0){ @@ -232,7 +236,33 @@ void Xasync(void){ Xerror("try again"); break; case 0: - pushredir(ROPEN, null, 0); + /* + * 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; |