From 31d1d48e199e99077fb30f6fb9a793be7bec756f Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 6 Aug 2010 16:34:43 +0100 Subject: [PATCH] Fix init ordering of /dev/console vs callers of modprobe Make /dev/console get initialised before any initialisation routine that invokes modprobe because if modprobe fails, it's going to want to open /dev/console, presumably to write an error message to. The problem with that is that if the /dev/console driver is not yet initialised, the chardev handler will call request_module() to invoke modprobe, which will fail, because we never compile /dev/console as a module. This will lead to a modprobe loop, showing the following in the kernel log: request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 request_module: runaway loop modprobe char-major-5-1 This can happen, for example, when the built in md5 module can't find the built in cryptomgr module (because the latter fails to initialise). The md5 module comes before the call to tty_init(), presumably because 'crypto' comes before 'drivers' alphabetically. Fix this by calling tty_init() from chrdev_init(). Signed-off-by: David Howells Signed-off-by: Linus Torvalds --- drivers/char/mem.c | 2 +- drivers/char/tty_io.c | 4 ++-- fs/char_dev.c | 1 + include/linux/tty.h | 3 +++ 4 files changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/char/mem.c b/drivers/char/mem.c index f54dab8acdcd..a398ecdbd758 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -916,7 +916,7 @@ static int __init chr_dev_init(void) NULL, devlist[minor].name); } - return 0; + return tty_init(); } fs_initcall(chr_dev_init); diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index d71f0fc34b46..507441ac6edb 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -3128,7 +3128,7 @@ static struct cdev tty_cdev, console_cdev; * Ok, now we can initialize the rest of the tty devices and can count * on memory allocations, interrupts etc.. */ -static int __init tty_init(void) +int __init tty_init(void) { cdev_init(&tty_cdev, &tty_fops); if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || @@ -3149,4 +3149,4 @@ static int __init tty_init(void) #endif return 0; } -module_init(tty_init); + diff --git a/fs/char_dev.c b/fs/char_dev.c index d6db933df2b2..f80a4f25123c 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "internal.h" diff --git a/include/linux/tty.h b/include/linux/tty.h index 931078b73226..7802a243ee13 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -552,6 +552,9 @@ static inline void tty_audit_push_task(struct task_struct *tsk, } #endif +/* tty_io.c */ +extern int __init tty_init(void); + /* tty_ioctl.c */ extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg); -- 2.20.1