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
diff --git a/arch/um/drivers/hostaudio_kern.c b/arch/um/drivers/hostaudio_kern.c
index 68142df..0c46e39 100644
--- a/arch/um/drivers/hostaudio_kern.c
+++ b/arch/um/drivers/hostaudio_kern.c
@@ -187,7 +187,9 @@
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 @@
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 @@
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 @@
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) {
diff --git a/drivers/net/wireless/libertas/if_usb.c b/drivers/net/wireless/libertas/if_usb.c
index 07ece9d..3ff6106 100644
--- a/drivers/net/wireless/libertas/if_usb.c
+++ b/drivers/net/wireless/libertas/if_usb.c
@@ -289,10 +289,13 @@
}
/* Upload firmware */
+ kparam_block_sysfs_write(fw_name);
if (__if_usb_prog_firmware(cardp, lbs_fw_name, BOOT_CMD_FW_BY_USB)) {
+ kparam_unblock_sysfs_write(fw_name);
lbs_deb_usbd(&udev->dev, "FW upload failed\n");
goto err_prog_firmware;
}
+ kparam_unblock_sysfs_write(fw_name);
if (!(priv = lbs_add_card(cardp, &udev->dev)))
goto err_prog_firmware;
diff --git a/drivers/net/wireless/libertas_tf/if_usb.c b/drivers/net/wireless/libertas_tf/if_usb.c
index b172f5d..41a4f21 100644
--- a/drivers/net/wireless/libertas_tf/if_usb.c
+++ b/drivers/net/wireless/libertas_tf/if_usb.c
@@ -811,12 +811,15 @@
lbtf_deb_enter(LBTF_DEB_USB);
+ kparam_block_sysfs_write(fw_name);
ret = request_firmware(&cardp->fw, lbtf_fw_name, &cardp->udev->dev);
if (ret < 0) {
pr_err("request_firmware() failed with %#x\n", ret);
pr_err("firmware %s not found\n", lbtf_fw_name);
+ kparam_unblock_sysfs_write(fw_name);
goto done;
}
+ kparam_unblock_sysfs_write(fw_name);
if (check_fwfile_format(cardp->fw->data, cardp->fw->size))
goto release_fw;
diff --git a/drivers/scsi/bfa/bfad.c b/drivers/scsi/bfa/bfad.c
index 915a29d..ca04cc9 100644
--- a/drivers/scsi/bfa/bfad.c
+++ b/drivers/scsi/bfa/bfad.c
@@ -788,6 +788,7 @@
memset(&driver_info, 0, sizeof(driver_info));
strncpy(driver_info.version, BFAD_DRIVER_VERSION,
sizeof(driver_info.version) - 1);
+ __kernel_param_lock();
if (host_name)
strncpy(driver_info.host_machine_name, host_name,
sizeof(driver_info.host_machine_name) - 1);
@@ -797,6 +798,7 @@
if (os_patch)
strncpy(driver_info.host_os_patch, os_patch,
sizeof(driver_info.host_os_patch) - 1);
+ __kernel_param_unlock();
strncpy(driver_info.os_device_name, bfad->pci_name,
sizeof(driver_info.os_device_name - 1));
diff --git a/drivers/usb/atm/ueagle-atm.c b/drivers/usb/atm/ueagle-atm.c
index 5b3f555..ea071a5 100644
--- a/drivers/usb/atm/ueagle-atm.c
+++ b/drivers/usb/atm/ueagle-atm.c
@@ -1577,6 +1577,7 @@
char file_arr[] = "CMVxy.bin";
char *file;
+ kparam_block_sysfs_write(cmv_file);
/* set proper name corresponding modem version and line type */
if (cmv_file[sc->modem_index] == NULL) {
if (UEA_CHIP_VERSION(sc) == ADI930)
@@ -1595,6 +1596,7 @@
strlcat(cmv_name, file, UEA_FW_NAME_MAX);
if (ver == 2)
strlcat(cmv_name, ".v2", UEA_FW_NAME_MAX);
+ kparam_unblock_sysfs_write(cmv_file);
}
static int request_cmvs_old(struct uea_softc *sc,
diff --git a/drivers/video/vt8623fb.c b/drivers/video/vt8623fb.c
index d31dc96..85d76ec 100644
--- a/drivers/video/vt8623fb.c
+++ b/drivers/video/vt8623fb.c
@@ -726,7 +726,9 @@
/* Prepare startup mode */
+ kparam_block_sysfs_write(mode_option);
rc = fb_find_mode(&(info->var), info, mode_option, NULL, 0, NULL, 8);
+ kparam_unblock_sysfs_write(mode_option);
if (! ((rc == 1) || (rc == 2))) {
rc = -EINVAL;
dev_err(info->device, "mode %s not found\n", mode_option);
diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
index 6d0bd19..be04d461 100644
--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -103,6 +103,7 @@
struct rate_control_ops *ops;
const char *alg_name;
+ kparam_block_sysfs_write(ieee80211_default_rc_algo);
if (!name)
alg_name = ieee80211_default_rc_algo;
else
@@ -120,6 +121,7 @@
/* try built-in one if specific alg requested but not found */
if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
+ kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
return ops;
}