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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
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7 files changed

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‎arch/um/drivers/hostaudio_kern.c

Lines changed: 10 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -187,7 +187,9 @@ static int hostaudio_open(struct inode *inode, struct file *file)
187187
int ret;
188188

189189
#ifdef DEBUG
190+
kparam_block_sysfs_write(dsp);
190191
printk(KERN_DEBUG "hostaudio: open called (host: %s)\n", dsp);
192+
kparam_unblock_sysfs_write(dsp);
191193
#endif
192194

193195
state = kmalloc(sizeof(struct hostaudio_state), GFP_KERNEL);
@@ -199,9 +201,11 @@ static int hostaudio_open(struct inode *inode, struct file *file)
199201
if (file->f_mode & FMODE_WRITE)
200202
w = 1;
201203

204+
kparam_block_sysfs_write(dsp);
202205
lock_kernel();
203206
ret = os_open_file(dsp, of_set_rw(OPENFLAGS(), r, w), 0);
204207
unlock_kernel();
208+
kparam_unblock_sysfs_write(dsp);
205209

206210
if (ret < 0) {
207211
kfree(state);
@@ -258,13 +262,17 @@ static int hostmixer_open_mixdev(struct inode *inode, struct file *file)
258262
if (file->f_mode & FMODE_WRITE)
259263
w = 1;
260264

265+
kparam_block_sysfs_write(mixer);
261266
lock_kernel();
262267
ret = os_open_file(mixer, of_set_rw(OPENFLAGS(), r, w), 0);
263268
unlock_kernel();
269+
kparam_unblock_sysfs_write(mixer);
264270

265271
if (ret < 0) {
272+
kparam_block_sysfs_write(dsp);
266273
printk(KERN_ERR "hostaudio_open_mixdev failed to open '%s', "
267274
"err = %d\n", dsp, -ret);
275+
kparam_unblock_sysfs_write(dsp);
268276
kfree(state);
269277
return ret;
270278
}
@@ -320,8 +328,10 @@ MODULE_LICENSE("GPL");
320328

321329
static int __init hostaudio_init_module(void)
322330
{
331+
__kernel_param_lock();
323332
printk(KERN_INFO "UML Audio Relay (host dsp = %s, host mixer = %s)\n",
324333
dsp, mixer);
334+
__kernel_param_unlock();
325335

326336
module_data.dev_audio = register_sound_dsp(&hostaudio_fops, -1);
327337
if (module_data.dev_audio < 0) {

‎drivers/net/wireless/libertas/if_usb.c

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -289,10 +289,13 @@ static int if_usb_probe(struct usb_interface *intf,
289289
}
290290

291291
/* Upload firmware */
292+
kparam_block_sysfs_write(fw_name);
292293
if (__if_usb_prog_firmware(cardp, lbs_fw_name, BOOT_CMD_FW_BY_USB)) {
294+
kparam_unblock_sysfs_write(fw_name);
293295
lbs_deb_usbd(&udev->dev, "FW upload failed\n");
294296
goto err_prog_firmware;
295297
}
298+
kparam_unblock_sysfs_write(fw_name);
296299

297300
if (!(priv = lbs_add_card(cardp, &udev->dev)))
298301
goto err_prog_firmware;

‎drivers/net/wireless/libertas_tf/if_usb.c

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -811,12 +811,15 @@ static int if_usb_prog_firmware(struct if_usb_card *cardp)
811811

812812
lbtf_deb_enter(LBTF_DEB_USB);
813813

814+
kparam_block_sysfs_write(fw_name);
814815
ret = request_firmware(&cardp->fw, lbtf_fw_name, &cardp->udev->dev);
815816
if (ret < 0) {
816817
pr_err("request_firmware() failed with %#x\n", ret);
817818
pr_err("firmware %s not found\n", lbtf_fw_name);
819+
kparam_unblock_sysfs_write(fw_name);
818820
goto done;
819821
}
822+
kparam_unblock_sysfs_write(fw_name);
820823

821824
if (check_fwfile_format(cardp->fw->data, cardp->fw->size))
822825
goto release_fw;

‎drivers/scsi/bfa/bfad.c

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -788,6 +788,7 @@ bfad_drv_init(struct bfad_s *bfad)
788788
memset(&driver_info, 0, sizeof(driver_info));
789789
strncpy(driver_info.version, BFAD_DRIVER_VERSION,
790790
sizeof(driver_info.version) - 1);
791+
__kernel_param_lock();
791792
if (host_name)
792793
strncpy(driver_info.host_machine_name, host_name,
793794
sizeof(driver_info.host_machine_name) - 1);
@@ -797,6 +798,7 @@ bfad_drv_init(struct bfad_s *bfad)
797798
if (os_patch)
798799
strncpy(driver_info.host_os_patch, os_patch,
799800
sizeof(driver_info.host_os_patch) - 1);
801+
__kernel_param_unlock();
800802

801803
strncpy(driver_info.os_device_name, bfad->pci_name,
802804
sizeof(driver_info.os_device_name - 1));

‎drivers/usb/atm/ueagle-atm.c

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1577,6 +1577,7 @@ static void cmvs_file_name(struct uea_softc *sc, char *const cmv_name, int ver)
15771577
char file_arr[] = "CMVxy.bin";
15781578
char *file;
15791579

1580+
kparam_block_sysfs_write(cmv_file);
15801581
/* set proper name corresponding modem version and line type */
15811582
if (cmv_file[sc->modem_index] == NULL) {
15821583
if (UEA_CHIP_VERSION(sc) == ADI930)
@@ -1595,6 +1596,7 @@ static void cmvs_file_name(struct uea_softc *sc, char *const cmv_name, int ver)
15951596
strlcat(cmv_name, file, UEA_FW_NAME_MAX);
15961597
if (ver == 2)
15971598
strlcat(cmv_name, ".v2", UEA_FW_NAME_MAX);
1599+
kparam_unblock_sysfs_write(cmv_file);
15981600
}
15991601

16001602
static int request_cmvs_old(struct uea_softc *sc,

‎drivers/video/vt8623fb.c

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -726,7 +726,9 @@ static int __devinit vt8623_pci_probe(struct pci_dev *dev, const struct pci_devi
726726

727727
/* Prepare startup mode */
728728

729+
kparam_block_sysfs_write(mode_option);
729730
rc = fb_find_mode(&(info->var), info, mode_option, NULL, 0, NULL, 8);
731+
kparam_unblock_sysfs_write(mode_option);
730732
if (! ((rc == 1) || (rc == 2))) {
731733
rc = -EINVAL;
732734
dev_err(info->device, "mode %s not found\n", mode_option);

‎net/mac80211/rate.c

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -103,6 +103,7 @@ ieee80211_rate_control_ops_get(const char *name)
103103
struct rate_control_ops *ops;
104104
const char *alg_name;
105105

106+
kparam_block_sysfs_write(ieee80211_default_rc_algo);
106107
if (!name)
107108
alg_name = ieee80211_default_rc_algo;
108109
else
@@ -120,6 +121,7 @@ ieee80211_rate_control_ops_get(const char *name)
120121
/* try built-in one if specific alg requested but not found */
121122
if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
122123
ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
124+
kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
123125

124126
return ops;
125127
}

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