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| author | Rusty Russell <rusty@rustcorp.com.au> | 2010-08-11 23:04:27 -0600 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2010-08-11 23:04:31 +0930 |
| commit | d6d1b650ae6acce73d55dd0246de22180303ae73 (patch) | |
| tree | 7a342999c119a5ee6395966cee91ddf5186f5665 /arch/um/drivers | |
| parent | dca41306395eab37e222ff9e72765e692fcc7251 (diff) | |
| download | linux-d6d1b650ae6acce73d55dd0246de22180303ae73.tar.gz linux-d6d1b650ae6acce73d55dd0246de22180303ae73.tar.bz2 linux-d6d1b650ae6acce73d55dd0246de22180303ae73.zip | |
param: simple locking for sysfs-writable charp parameters
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 <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Jing Huang <huangj@brocade.com>
Cc: James E.J. Bottomley <James.Bottomley@suse.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: David S. Miller <davem@davemloft.net>
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
Diffstat (limited to 'arch/um/drivers')
| -rw-r--r-- | arch/um/drivers/hostaudio_kern.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/um/drivers/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c index 68142df76608..0c46e398cd8f 100644 --- a/arch/um/drivers/hostaudio_kern.c +++ b/arch/um/drivers/hostaudio_kern.c @@ -187,7 +187,9 @@ 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); @@ -199,9 +201,11 @@ static int hostaudio_open(struct inode *inode, struct file *file) if (file->f_mode & FMODE_WRITE) w = 1; + kparam_block_sysfs_write(dsp); lock_kernel(); ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0); unlock_kernel(); + kparam_unblock_sysfs_write(dsp); if (ret < 0) { kfree(state); @@ -258,13 +262,17 @@ static int hostmixer_open_mixdev(struct inode *inode, struct file *file) if (file->f_mode & FMODE_WRITE) w = 1; + kparam_block_sysfs_write(mixer); lock_kernel(); ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0); unlock_kernel(); + 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; } @@ -320,8 +328,10 @@ 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) { |