diff options
| -rw-r--r-- | login-utils/su-common.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/login-utils/su-common.c b/login-utils/su-common.c index 925cef983..b9deeeab1 100644 --- a/login-utils/su-common.c +++ b/login-utils/su-common.c @@ -196,14 +196,28 @@ static int wait_for_child(struct su_context *su) return su->childstatus; if (su->child != (pid_t) -1) { + /* + * The "su" parent process spends all time here in waitpid(), + * but "su --pty" uses pty_proxy_master() and waitpid() is only + * called to pick up child status or to react to SIGSTOP. + */ DBG(SIG, ul_debug("waiting for child [%d]...", su->child)); for (;;) { pid = waitpid(su->child, &status, WUNTRACED); if (pid != (pid_t) - 1 && WIFSTOPPED(status)) { + DBG(SIG, ul_debug(" child got SIGSTOP -- stop all session")); kill(getpid(), SIGSTOP); /* once we get here, we must have resumed */ kill(pid, SIGCONT); + DBG(SIG, ul_debug(" session resumed -- continue")); +#ifdef USE_PTY + /* Let's go back to pty_proxy_master() */ + if (su->pty_sigfd != -1) { + DBG(SIG, ul_debug(" leaving on child SIGSTOP")); + return 0; + } +#endif } else break; } @@ -421,8 +435,14 @@ static int pty_handle_signal(struct su_context *su, int fd) switch (info.ssi_signo) { case SIGCHLD: DBG(SIG, ul_debug(" get signal SIGCHLD")); - wait_for_child(su); - su->poll_timeout = 10; + + /* The child terminated or stopped. Note that we ignore SIGCONT + * here, because stop/cont semantic is handled by wait_for_child() */ + if (info.ssi_code == CLD_EXITED || info.ssi_status == SIGSTOP) + wait_for_child(su); + /* The child is dead, force poll() timeout. */ + if (su->child == (pid_t) -1) + su->poll_timeout = 10; return 0; case SIGWINCH: DBG(SIG, ul_debug(" get signal SIGWINCH")); @@ -555,6 +575,8 @@ static void pty_proxy_master(struct su_context *su) } } + close(su->pty_sigfd); + su->pty_sigfd = -1; DBG(PTY, ul_debug("poll() done [signal=%d, rc=%d]", caught_signal, rc)); } #endif /* USE_PTY */ |