[PATCH 0/3 V2] iFixes for b43 and b43legacy

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4 messages, 2 authors, 2014-01-12 · open the first message on its own page

[PATCH 0/3 V2] iFixes for b43 and b43legacy

From: Larry Finger <hidden>
Date: 2014-01-12 21:11:36

These 3 fixes should be applied as soon as possible. I understand that 3.13
will be released soon. As all 3 are marked for stable, inclusion in 3.14
will be satisfactory.

V2 - Patch 1 is unchanged, but 2 and 3 are fixed to remove any race conditions.

Larry


Larry Finger (3):
  b43: Fix lockdep splat
  b43: Fix unload oops if firmware is not available
  b43legacy: Fix unload oops if firmware is not available

 drivers/net/wireless/b43/b43.h        |  4 ++--
 drivers/net/wireless/b43/main.c       | 27 ++++++++++++++++-----------
 drivers/net/wireless/b43legacy/main.c |  1 +
 3 files changed, 19 insertions(+), 13 deletions(-)

-- 
1.8.4

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[PATCH 1/3 V2] b43: Fix lockdep splat

From: Larry Finger <hidden>
Date: 2014-01-12 21:11:37

In https://bugzilla.kernel.org/show_bug.cgi?id=67561, a locking dependency is reported
when b43 is used with hostapd, and rfkill is used to kill the radio output.

The lockdep splat (in part) is as follows:

======================================================
[ INFO: possible circular locking dependency detected ]
3.12.0 #1 Not tainted
-------------------------------------------------------
rfkill/10040 is trying to acquire lock:
 (rtnl_mutex){+.+.+.}, at: [<ffffffff8146f282>] rtnl_lock+0x12/0x20

but task is already holding lock:
 (rfkill_global_mutex){+.+.+.}, at: [<ffffffffa04832ca>] rfkill_fop_write+0x6a/0x170 [rfkill]

--snip--

Chain exists of:
  rtnl_mutex --> misc_mtx --> rfkill_global_mutex

The fix is to move the initialization of the hardware random number generator
outside the code range covered by the rtnl_mutex.

Reported-by: yury <redacted>
Tested-by: yury <redacted>
Signed-off-by: Larry Finger <redacted>
Cc: Stable <redacted>
---

V2 is identical to V1.

 drivers/net/wireless/b43/main.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index ccd24f0a..86b2030 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -2424,6 +2424,7 @@ error:
 
 static int b43_one_core_attach(struct b43_bus_dev *dev, struct b43_wl *wl);
 static void b43_one_core_detach(struct b43_bus_dev *dev);
+static int b43_rng_init(struct b43_wl *wl);
 
 static void b43_request_firmware(struct work_struct *work)
 {
@@ -2475,6 +2476,10 @@ start_ieee80211:
 		goto err_one_core_detach;
 	wl->hw_registred = true;
 	b43_leds_register(wl->current_dev);
+
+	/* Register HW RNG driver */
+	b43_rng_init(wl);
+
 	goto out;
 
 err_one_core_detach:
@@ -4636,9 +4641,6 @@ static void b43_wireless_core_exit(struct b43_wldev *dev)
 	if (!dev || b43_status(dev) != B43_STAT_INITIALIZED)
 		return;
 
-	/* Unregister HW RNG driver */
-	b43_rng_exit(dev->wl);
-
 	b43_set_status(dev, B43_STAT_UNINIT);
 
 	/* Stop the microcode PSM. */
@@ -4795,9 +4797,6 @@ static int b43_wireless_core_init(struct b43_wldev *dev)
 
 	b43_set_status(dev, B43_STAT_INITIALIZED);
 
-	/* Register HW RNG driver */
-	b43_rng_init(dev->wl);
-
 out:
 	return err;
 
@@ -5464,6 +5463,9 @@ static void b43_bcma_remove(struct bcma_device *core)
 
 	b43_one_core_detach(wldev->dev);
 
+	/* Unregister HW RNG driver */
+	b43_rng_exit(wl);
+
 	b43_leds_unregister(wl);
 
 	ieee80211_free_hw(wl->hw);
@@ -5541,6 +5543,9 @@ static void b43_ssb_remove(struct ssb_device *sdev)
 
 	b43_one_core_detach(dev);
 
+	/* Unregister HW RNG driver */
+	b43_rng_exit(wl);
+
 	if (list_empty(&wl->devlist)) {
 		b43_leds_unregister(wl);
 		/* Last core on the chip unregistered.
-- 
1.8.4

[PATCH 2/3 V2] b43: Fix unload oops if firmware is not available

From: Larry Finger <hidden>
Date: 2014-01-12 21:11:38

The asyncronous firmware load uses a completion struct to hold firmware
processing until the user-space routines are up and running. There is.
however, a problem in that the waiter is nevered canceled during teardown.
As a result, unloading the driver when firmware is not available causes an oops.

To be able to access the completion structure at teardown, it had to be moved
into the b43_wldev structure.

This patch also fixes a typo in a comment.

Signed-off-by: Larry Finger <redacted>
Cc: Stable <redacted>
---

V2 - Addresses the comments of Ben Hutchings and removes the race condition.

 drivers/net/wireless/b43/b43.h  |  4 ++--
 drivers/net/wireless/b43/main.c | 10 +++++-----
 2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index 7f3d461..54376fd 100644
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -731,8 +731,6 @@ enum b43_firmware_file_type {
 struct b43_request_fw_context {
 	/* The device we are requesting the fw for. */
 	struct b43_wldev *dev;
-	/* a completion event structure needed if this call is asynchronous */
-	struct completion fw_load_complete;
 	/* a pointer to the firmware object */
 	const struct firmware *blob;
 	/* The type of firmware to request. */
@@ -809,6 +807,8 @@ enum {
 struct b43_wldev {
 	struct b43_bus_dev *dev;
 	struct b43_wl *wl;
+	/* a completion event structure needed if this call is asynchronous */
+	struct completion fw_load_complete;
 
 	/* The device initialization status.
 	 * Use b43_status() to query. */
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 86b2030..c75237e 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -2070,6 +2070,7 @@ void b43_do_release_fw(struct b43_firmware_file *fw)
 
 static void b43_release_firmware(struct b43_wldev *dev)
 {
+	complete(&dev->fw_load_complete);
 	b43_do_release_fw(&dev->fw.ucode);
 	b43_do_release_fw(&dev->fw.pcm);
 	b43_do_release_fw(&dev->fw.initvals);
@@ -2095,7 +2096,7 @@ static void b43_fw_cb(const struct firmware *firmware, void *context)
 	struct b43_request_fw_context *ctx = context;
 
 	ctx->blob = firmware;
-	complete(&ctx->fw_load_complete);
+	complete(&ctx->dev->fw_load_complete);
 }
 
 int b43_do_request_fw(struct b43_request_fw_context *ctx,
@@ -2142,7 +2143,7 @@ int b43_do_request_fw(struct b43_request_fw_context *ctx,
 	}
 	if (async) {
 		/* do this part asynchronously */
-		init_completion(&ctx->fw_load_complete);
+		init_completion(&ctx->dev->fw_load_complete);
 		err = request_firmware_nowait(THIS_MODULE, 1, ctx->fwname,
 					      ctx->dev->dev->dev, GFP_KERNEL,
 					      ctx, b43_fw_cb);
@@ -2150,12 +2151,11 @@ int b43_do_request_fw(struct b43_request_fw_context *ctx,
 			pr_err("Unable to load firmware\n");
 			return err;
 		}
-		/* stall here until fw ready */
-		wait_for_completion(&ctx->fw_load_complete);
+		wait_for_completion(&ctx->dev->fw_load_complete);
 		if (ctx->blob)
 			goto fw_ready;
 	/* On some ARM systems, the async request will fail, but the next sync
-	 * request works. For this reason, we dall through here
+	 * request works. For this reason, we fall through here
 	 */
 	}
 	err = request_firmware(&ctx->blob, ctx->fwname,
-- 
1.8.4

[PATCH 3/3 V2] b43legacy: Fix unload oops if firmware is not available

From: Larry Finger <hidden>
Date: 2014-01-12 21:11:39

The asyncronous firmware load uses a completion struct to hold firmware
processing until the user-space routines are up and running. There is.
however, a problem in that the waiter is nevered canceled during teardown.
As a result, unloading the driver when firmware is not available causes an oops.

Signed-off-by: Larry Finger <redacted>
Cc: Stable <redacted>
---
V2 - Addresses the comments of Ben Hutchings and removes the race condition.

 drivers/net/wireless/b43legacy/main.c | 1 +
 1 file changed, 1 insertion(+)
diff --git a/drivers/net/wireless/b43legacy/main.c b/drivers/net/wireless/b43legacy/main.c
index 5726688..349c776 100644
--- a/drivers/net/wireless/b43legacy/main.c
+++ b/drivers/net/wireless/b43legacy/main.c
@@ -3919,6 +3919,7 @@ static void b43legacy_remove(struct ssb_device *dev)
 	 * as the ieee80211 unreg will destroy the workqueue. */
 	cancel_work_sync(&wldev->restart_work);
 	cancel_work_sync(&wl->firmware_load);
+	complete(&wldev->fw_load_complete);
 
 	B43legacy_WARN_ON(!wl);
 	if (!wldev->fw.ucode)
-- 
1.8.4
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