FAILED: patch "[PATCH] Drivers: hv: vmbus: Check for ring when getting debug info" failed to apply to 4.4-stable tree

PATCH [email protected] 2 participants 2 messages Jan 27, 2019 – Jan 28, 2019

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Stable branch Hyper-V/Azure core and drivers

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lore

[email protected]

author maintainer

2019-01-27 15:42 UTC #0 lore raw

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ba50bf1ce9a51fc97db58b96d01306aa70bc3979 Mon Sep 17 00:00:00 2001
From: Dexuan Cui <[email protected]>
Date: Mon, 17 Dec 2018 20:16:09 +0000
Subject: [PATCH] Drivers: hv: vmbus: Check for ring when getting debug info

fc96df16a1ce is good and can already fix the "return stack garbage" issue, but let's also improve hv_ringbuffer_get_debuginfo(), which would silently return stack garbage, if people forget to check channel->state or ring_info->ring_buffer, when using the function in the future.

Having an error check in the function would eliminate the potential risk.

Add a Fixes tag to indicate the patch depdendency.

Fixes fc96df16a1ce ("Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels")

Cc [email protected]

Cc K. Y. Srinivasan <[email protected]>

Cc Haiyang Zhang <[email protected]>

Signed-off-by Stephen Hemminger <[email protected]>

Signed-off-by Dexuan Cui <[email protected]>

Signed-off-by Sasha Levin <[email protected]>

drivers/hv/ring_buffer.c +15 ~~-16~~

index 64d0c85d5161..1f1a55e07733 100644
@@ -164,26 +164,25 @@ hv_get_ringbuffer_availbytes(const struct hv_ring_buffer_info *rbi,
 }
 
 /* Get various debug metrics for the specified ring buffer. */
-void hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
-				 struct hv_ring_buffer_debug_info *debug_info)
+int hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
+				struct hv_ring_buffer_debug_info *debug_info)
 {
 	u32 bytes_avail_towrite;
 	u32 bytes_avail_toread;
 
-	if (ring_info->ring_buffer) {
-		hv_get_ringbuffer_availbytes(ring_info,
-					&bytes_avail_toread,
-					&bytes_avail_towrite);
-
-		debug_info->bytes_avail_toread = bytes_avail_toread;
-		debug_info->bytes_avail_towrite = bytes_avail_towrite;
-		debug_info->current_read_index =
-			ring_info->ring_buffer->read_index;
-		debug_info->current_write_index =
-			ring_info->ring_buffer->write_index;
-		debug_info->current_interrupt_mask =
-			ring_info->ring_buffer->interrupt_mask;
-	}
+	if (!ring_info->ring_buffer)
+		return -EINVAL;
+
+	hv_get_ringbuffer_availbytes(ring_info,
+				     &bytes_avail_toread,
+				     &bytes_avail_towrite);
+	debug_info->bytes_avail_toread = bytes_avail_toread;
+	debug_info->bytes_avail_towrite = bytes_avail_towrite;
+	debug_info->current_read_index = ring_info->ring_buffer->read_index;
+	debug_info->current_write_index = ring_info->ring_buffer->write_index;
+	debug_info->current_interrupt_mask
+		= ring_info->ring_buffer->interrupt_mask;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(hv_ringbuffer_get_debuginfo);

drivers/hv/vmbus_drv.c +61 ~~-30~~

181 lines not on this page · raw message

include/linux/hyperv.h +3 -2

index f0885cc01db6..dcb6977afce9 100644
@@ -1159,8 +1159,9 @@ struct hv_ring_buffer_debug_info {
 	u32 bytes_avail_towrite;
 };
 
-void hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
-			    struct hv_ring_buffer_debug_info *debug_info);
+
+int hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
+				struct hv_ring_buffer_debug_info *debug_info);
 
 /* Vmbus interface */
 #define vmbus_driver_register(driver)	\

Dexuan Cui

maintainer

2019-01-28 02:13 UTC #1 lore raw

Quoted 324 lines

From: [email protected] <[email protected]>
Sent: Sunday, January 27, 2019 7:43 AM
To: Dexuan Cui <[email protected]>; Haiyang Zhang <[email protected]>; KY Srinivasan <[email protected]>; [email protected]; Stephen Hemminger <[email protected]>
Cc: [email protected]
Subject: FAILED: patch "[PATCH] Drivers: hv: vmbus: Check for ring when getting debug info" failed to apply to 4.4-stable tree

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Having an error check in the function would eliminate the potential risk.

Add a Fixes tag to indicate the patch depdendency.

Fixes fc96df16a1ce ("Drivers: hv: vmbus: Return -EINVAL for the sys files for

unopened channels")

Cc [email protected]

Cc K. Y. Srinivasan <[email protected]>

Cc Haiyang Zhang <[email protected]>

Signed-off-by Stephen Hemminger <[email protected]>

Signed-off-by Dexuan Cui <[email protected]>

Signed-off-by Sasha Levin <[email protected]>

drivers/hv/ring_buffer.c +15 ~~-16~~

index 64d0c85d5161..1f1a55e07733 100644
@@ -164,26 +164,25 @@ hv_get_ringbuffer_availbytes(const struct
 hv_ring_buffer_info *rbi,
 }
 
 /* Get various debug metrics for the specified ring buffer. */
-void hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info
 *ring_info,
-				 struct hv_ring_buffer_debug_info *debug_info)
+int hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
+				struct hv_ring_buffer_debug_info *debug_info)
 {
 	u32 bytes_avail_towrite;
 	u32 bytes_avail_toread;
 
-	if (ring_info->ring_buffer) {
-		hv_get_ringbuffer_availbytes(ring_info,
-					&bytes_avail_toread,
-					&bytes_avail_towrite);
-
-		debug_info->bytes_avail_toread = bytes_avail_toread;
-		debug_info->bytes_avail_towrite = bytes_avail_towrite;
-		debug_info->current_read_index =
-			ring_info->ring_buffer->read_index;
-		debug_info->current_write_index =
-			ring_info->ring_buffer->write_index;
-		debug_info->current_interrupt_mask =
-			ring_info->ring_buffer->interrupt_mask;
-	}
+	if (!ring_info->ring_buffer)
+		return -EINVAL;
+
+	hv_get_ringbuffer_availbytes(ring_info,
+				     &bytes_avail_toread,
+				     &bytes_avail_towrite);
+	debug_info->bytes_avail_toread = bytes_avail_toread;
+	debug_info->bytes_avail_towrite = bytes_avail_towrite;
+	debug_info->current_read_index = ring_info->ring_buffer->read_index;
+	debug_info->current_write_index = ring_info->ring_buffer->write_index;
+	debug_info->current_interrupt_mask
+		= ring_info->ring_buffer->interrupt_mask;
+	return 0;
 }

EXPORT_SYMBOL_GPL(hv_ringbuffer_get_debuginfo);

drivers/hv/vmbus_drv.c +7 -3

index d0ff65675292..403fee01572c 100644
@@ -313,12 +313,16 @@ static ssize_t out_intr_mask_show(struct device
 *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info outbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 &outbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
+					  &outbound);
+	if (ret < 0)
+		return ret;
+
 	return sprintf(buf, "%d\n", outbound.current_interrupt_mask);

}
static DEVICE_ATTR_RO(out_intr_mask);

drivers/hv/vmbus_drv.c +6 -3

@@ -328,12 +332,15 @@ static ssize_t out_read_index_show(struct device
 *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info outbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 &outbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
+					  &outbound);
+	if (ret < 0)
+		return ret;
 	return sprintf(buf, "%d\n", outbound.current_read_index);

}
static DEVICE_ATTR_RO(out_read_index);

drivers/hv/vmbus_drv.c +6 -3

@@ -344,12 +351,15 @@ static ssize_t out_write_index_show(struct device
 *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info outbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 &outbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
+					  &outbound);
+	if (ret < 0)
+		return ret;
 	return sprintf(buf, "%d\n", outbound.current_write_index);

}
static DEVICE_ATTR_RO(out_write_index);

drivers/hv/vmbus_drv.c +6 -3

@@ -360,12 +370,15 @@ static ssize_t out_read_bytes_avail_show(struct
 device *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info outbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 &outbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
+					  &outbound);
+	if (ret < 0)
+		return ret;
 	return sprintf(buf, "%d\n", outbound.bytes_avail_toread);

}
static DEVICE_ATTR_RO(out_read_bytes_avail);

drivers/hv/vmbus_drv.c +6 -3

@@ -376,12 +389,15 @@ static ssize_t out_write_bytes_avail_show(struct
 device *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info outbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 &outbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
+					  &outbound);
+	if (ret < 0)
+		return ret;
 	return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);

}
static DEVICE_ATTR_RO(out_write_bytes_avail);

drivers/hv/vmbus_drv.c +6 -3

@@ -391,12 +407,15 @@ static ssize_t in_intr_mask_show(struct device
 *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info inbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound,
 &inbound);
+	if (ret < 0)
+		return ret;
+
 	return sprintf(buf, "%d\n", inbound.current_interrupt_mask);

}
static DEVICE_ATTR_RO(in_intr_mask);

drivers/hv/vmbus_drv.c +6 -3

@@ -406,12 +425,15 @@ static ssize_t in_read_index_show(struct device
 *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info inbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound,
 &inbound);
+	if (ret < 0)
+		return ret;
+
 	return sprintf(buf, "%d\n", inbound.current_read_index);

}
static DEVICE_ATTR_RO(in_read_index);

drivers/hv/vmbus_drv.c +6 -3

@@ -421,12 +443,15 @@ static ssize_t in_write_index_show(struct device
 *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info inbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound,
 &inbound);
+	if (ret < 0)
+		return ret;
+
 	return sprintf(buf, "%d\n", inbound.current_write_index);

}
static DEVICE_ATTR_RO(in_write_index);

drivers/hv/vmbus_drv.c +6 -3

@@ -437,12 +462,15 @@ static ssize_t in_read_bytes_avail_show(struct
 device *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info inbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound,
 &inbound);
+	if (ret < 0)
+		return ret;
+
 	return sprintf(buf, "%d\n", inbound.bytes_avail_toread);

}
static DEVICE_ATTR_RO(in_read_bytes_avail);

drivers/hv/vmbus_drv.c +6 -3

@@ -453,12 +481,15 @@ static ssize_t in_write_bytes_avail_show(struct
 device *dev,
 {
 	struct hv_device *hv_dev = device_to_hv_device(dev);
 	struct hv_ring_buffer_debug_info inbound;
+	int ret;
 
 	if (!hv_dev->channel)
 		return -ENODEV;
-	if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
-		return -EINVAL;
-	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
+
+	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound,
 &inbound);
+	if (ret < 0)
+		return ret;
+
 	return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);

}
static DEVICE_ATTR_RO(in_write_bytes_avail);

include/linux/hyperv.h +3 -2

index f0885cc01db6..dcb6977afce9 100644
@@ -1159,8 +1159,9 @@ struct hv_ring_buffer_debug_info {
 	u32 bytes_avail_towrite;
 };
 
-void hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info
 *ring_info,
-			    struct hv_ring_buffer_debug_info *debug_info);
+
+int hv_ringbuffer_get_debuginfo(const struct hv_ring_buffer_info *ring_info,
+				struct hv_ring_buffer_debug_info *debug_info);
 
 /* Vmbus interface */

Quoted 1 line

#define vmbus_driver_register(driver) \

We don't need to apply this patch to the 4.4-stable tree, because:
1. This is just a simple code refactoring, which doesn't really have a functional change.
2. We have to backport at least 2 more patches to apply this patch cleanly, which doesn't deserve the effort to me.

Thanks,
-- Dexuan