don't set up console for lxc-execute

Currently due to some safety checks for !rootfs.path, lxc-execute works ok if you do not set lxc.rootfs at all in your lxc.conf. But if you set lxc.rootfs = '/', then it sets up console, and when you do an lxc-execute, the console appears hung. However the lxc.rootfs NULL check was just incidental to not dereference a NULL pointer. In fact we should not be setting up a console if the container isn't running a full-fledged distro with a getty/login running on the container's /dev/console. Have lxc_execute() mark in lxc_conf that this is a lxc-execute and not an lxc-start, and don't set up the console. The issue is documented at https://sourceforge.net/p/lxc/bugs/67/ . Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Acked-by: Stéphane Graber <stgraber@ubuntu.com> Acked-by: Dwight Engen <dwight.engen@oracle.com>

don't set up console for lxc-execute
37903589 · Serge Hallyn · b5159817 · 37903589 · 37903589 · 37903589
Commit 37903589 authored Jun 13, 2013 by Serge Hallyn
Show whitespace changes
Inline Side-by-side

Showing with 14 additions and 2 deletions

conf.c src/lxc/conf.c +2 -2

conf.h src/lxc/conf.h +1 -0

console.c src/lxc/console.c +10 -0

execute.c src/lxc/execute.c +1 -0

No files found.
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -2836,7 +2836,7 @@ int lxc_setup(const char *name, struct lxc_conf *lxc_conf)
 		}
 	}
-	if (setup_console(&lxc_conf->rootfs, &lxc_conf->console, lxc_conf->ttydir)) {
+	if (!lxc_conf->is_execute && setup_console(&lxc_conf->rootfs, &lxc_conf->console, lxc_conf->ttydir)) {
 		ERROR("failed to setup the console for '%s'", name);
 		return -1;
 	}
@@ -2846,7 +2846,7 @@ int lxc_setup(const char *name, struct lxc_conf *lxc_conf)
 			ERROR("failed to setup kmsg for '%s'", name);
 	}
-	if (setup_tty(&lxc_conf->rootfs, &lxc_conf->tty_info, lxc_conf->ttydir)) {
+	if (!lxc_conf->is_execute && setup_tty(&lxc_conf->rootfs, &lxc_conf->tty_info, lxc_conf->ttydir)) {
 		ERROR("failed to setup the ttys for '%s'", name);
 		return -1;
 	}

--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -251,6 +251,7 @@ struct saved_nic {
 };
 struct lxc_conf {
+	int is_execute;
 	char *fstab;
 	int tty;
 	int pts;

--- a/src/lxc/console.c
+++ b/src/lxc/console.c
@@ -272,6 +272,11 @@ int lxc_console_mainloop_add(struct lxc_epoll_descr *descr,
 	struct lxc_conf *conf = handler->conf;
 	struct lxc_console *console = &conf->console;
+	if (conf->is_execute) {
+		INFO("no console for lxc-execute.");
+		return 0;
+	}
 	if (!conf->rootfs.path) {
 		INFO("no rootfs, no console.");
 		return 0;
@@ -559,6 +564,11 @@ int lxc_console_create(struct lxc_conf *conf)
 {
 	struct lxc_console *console = &conf->console;
+	if (conf->is_execute) {
+		INFO("no console for lxc-execute.");
+		return 0;
+	}
 	if (!conf->rootfs.path)
 		return 0;

--- a/src/lxc/execute.c
+++ b/src/lxc/execute.c
@@ -165,5 +165,6 @@ int lxc_execute(const char *name, char *const argv[], int quiet,
 	if (lxc_check_inherited(conf, -1))
 		return -1;
+	conf->is_execute = 1;
 	return __lxc_start(name, conf, &execute_start_ops, &args, lxcpath);
 }