switch_root: don't bail out when console doesn't exist

Busybox is very often used in initramfs at the end of which usually
there is a switch_root to the actual rootfs. There are many cases where
the console kernel argument is either just a placeholder (for example
RaspberryPi uses serial0 and serial1) or configured as null to avoid any
console messages - usually you would see such of a setup in production
environments.

Currently busybox bails out if can't open the console argument. If this
happenes in initramfs and if the console=null for example, you get in a
blind kernel panic. Avoid this by only warning instead of dying.

function                                             old     new   delta
switch_root_main                                     371     368      -3

Signed-off-by: Andrei Gherzan <andrei@gherzan.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Andrei Gherzan 2017-03-24 16:39:08 +01:00 committed by Denys Vlasenko
parent 876c121ccb
commit e3b65ab43d

View File

@ -141,10 +141,12 @@ int switch_root_main(int argc UNUSED_PARAM, char **argv)
// If a new console specified, redirect stdin/stdout/stderr to it
if (console) {
close(0);
xopen(console, O_RDWR);
xdup2(0, 1);
xdup2(0, 2);
int fd = open_or_warn(console, O_RDWR);
if (fd >= 0) {
xmove_fd(fd, 0);
xdup2(0, 1);
xdup2(0, 2);
}
}
// Exec real init