From a7c888650fbb35aac7b6d963b6c6d9a655c0c9be Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 27 Jul 2010 10:40:16 +1000 Subject: param:lock-charp-simple Since the writing to sysfs can free the old one, we need to block that when we access the charp variables. Signed-off-by: Rusty Russell Reviewed-by: Takashi Iwai Tested-by: Phil Carmody Cc: Jeff Dike Cc: Dan Williams Cc: John W. Linville Cc: Jing Huang Cc: James E.J. Bottomley Cc: Greg Kroah-Hartman Cc: Johannes Berg Cc: David S. Miller Cc: user-mode-linux-devel@lists.sourceforge.net Cc: libertas-dev@lists.infradead.org Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-usb@vger.kernel.org --- arch/um/drivers/hostaudio_kern.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/um') diff --git a/arch/um/drivers/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c index ae42695c3597..162855ce32b4 100644 --- a/arch/um/drivers/hostaudio_kern.c +++ b/arch/um/drivers/hostaudio_kern.c @@ -186,7 +186,9 @@ static int hostaudio_open(struct inode *inode, struct file *file) int ret; #ifdef DEBUG + kparam_block_sysfs_write(dsp); printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp); + kparam_unblock_sysfs_write(dsp); #endif state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL); @@ -198,7 +200,9 @@ static int hostaudio_open(struct inode *inode, struct file *file) if (file->f_mode & FMODE_WRITE) w = 1; + kparam_block_sysfs_write(dsp); ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0); + kparam_unblock_sysfs_write(dsp); if (ret < 0) { kfree(state); return ret; @@ -254,11 +258,15 @@ static int hostmixer_open_mixdev(struct inode *inode, struct file *file) if (file->f_mode & FMODE_WRITE) w = 1; + kparam_block_sysfs_write(mixer); ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0); + kparam_unblock_sysfs_write(mixer); if (ret < 0) { + kparam_block_sysfs_write(dsp); printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', " "err = %d\n", dsp, -ret); + kparam_unblock_sysfs_write(dsp); kfree(state); return ret; } @@ -314,8 +322,10 @@ MODULE_LICENSE("GPL"); static int __init hostaudio_init_module(void) { + __kernel_param_lock(); printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n", dsp, mixer); + __kernel_param_unlock(); module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1); if (module_data.dev_audio < 0) { -- cgit v1.2.3