From fcedbb293ee4d67399a6c231c5e8b7ceecfac9bf Mon Sep 17 00:00:00 2001 From: Kimberly Brown Date: Thu, 14 Mar 2019 16:05:00 -0400 Subject: Drivers: hv: vmbus: Refactor chan->state if statement MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The chan->state "if statement" was introduced in commit 6712cc9c2211 ("vmbus: don't return values for uninitalized channels"). That commit states that the purpose of the chan->state "if statement" is to prevent returning garbage or causing a kernel OOPS when the channel ring buffer is not initialized. The changes in this patch provide the same protection. Refactor the chan->state “if statement” in vmbus_chan_attr_show(): - Instead of checking the channel state in the "if statement", check whether the channel ring buffer pointer is NULL. Checking the ring buffer pointer makes this code consistent with hv_ringbuffer_get_debuginfo(). - Move the "if statement" to the four "_show" functions that access a channel ring buffer. Only four of the channel-level "_show" functions access a ring buffer. The ring buffer pointer does not need to be checked before calling the other "_show" functions, and moving the ring buffer pointer "if statement" to the "_show" functions that access a ring buffer makes the purpose of the "if statement" clear. Signed-off-by: Kimberly Brown Reviewed-by: Michael Kelley Signed-off-by: Sasha Levin --- drivers/hv/vmbus_drv.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index b23aea86d029..6aa79b6a6750 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1435,9 +1435,6 @@ static ssize_t vmbus_chan_attr_show(struct kobject *kobj, if (!attribute->show) return -EIO; - if (chan->state != CHANNEL_OPENED_STATE) - return -EINVAL; - return attribute->show(chan, buf); } @@ -1449,6 +1446,9 @@ static ssize_t out_mask_show(const struct vmbus_channel *channel, char *buf) { const struct hv_ring_buffer_info *rbi = &channel->outbound; + if (!rbi->ring_buffer) + return -EINVAL; + return sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask); } static VMBUS_CHAN_ATTR_RO(out_mask); @@ -1457,6 +1457,9 @@ static ssize_t in_mask_show(const struct vmbus_channel *channel, char *buf) { const struct hv_ring_buffer_info *rbi = &channel->inbound; + if (!rbi->ring_buffer) + return -EINVAL; + return sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask); } static VMBUS_CHAN_ATTR_RO(in_mask); @@ -1465,6 +1468,9 @@ static ssize_t read_avail_show(const struct vmbus_channel *channel, char *buf) { const struct hv_ring_buffer_info *rbi = &channel->inbound; + if (!rbi->ring_buffer) + return -EINVAL; + return sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi)); } static VMBUS_CHAN_ATTR_RO(read_avail); @@ -1473,6 +1479,9 @@ static ssize_t write_avail_show(const struct vmbus_channel *channel, char *buf) { const struct hv_ring_buffer_info *rbi = &channel->outbound; + if (!rbi->ring_buffer) + return -EINVAL; + return sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi)); } static VMBUS_CHAN_ATTR_RO(write_avail); -- cgit v1.2.3