init: open code setting up stdin/stdout/stderr

Don't rely on the implicit set_fs(KERNEL_DS) for ksys_open to work, but
instead open a struct file for /dev/console and then install it as FD
0/1/2 manually.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christoph Hellwig 2020-06-07 17:44:28 +02:00
parent bf6419e4d5
commit 8f740636d9

View file

@ -1457,15 +1457,19 @@ static int __ref kernel_init(void *unused)
"See Linux Documentation/admin-guide/init.rst for guidance.");
}
/* Open /dev/console, for stdin/stdout/stderr, this should never fail */
void console_on_rootfs(void)
{
/* Open the /dev/console as stdin, this should never fail */
if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
pr_err("Warning: unable to open an initial console.\n");
struct file *file = filp_open("/dev/console", O_RDWR, 0);
/* create stdout/stderr */
(void) ksys_dup(0);
(void) ksys_dup(0);
if (IS_ERR(file)) {
pr_err("Warning: unable to open an initial console.\n");
return;
}
get_file_rcu_many(file, 2);
fd_install(get_unused_fd_flags(0), file);
fd_install(get_unused_fd_flags(0), file);
fd_install(get_unused_fd_flags(0), file);
}
static noinline void __init kernel_init_freeable(void)