3.16.66-rc1 review patch. If anyone has any objections, please let me know.
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From: Dexuan Cui decui@microsoft.com
commit ba50bf1ce9a51fc97db58b96d01306aa70bc3979 upstream.
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: K. Y. Srinivasan kys@microsoft.com Cc: Haiyang Zhang haiyangz@microsoft.com Signed-off-by: Stephen Hemminger sthemmin@microsoft.com Signed-off-by: Dexuan Cui decui@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/hv/ring_buffer.c | 31 +++++++------- drivers/hv/vmbus_drv.c | 91 +++++++++++++++++++++++++++------------- include/linux/hyperv.h | 5 ++- 3 files changed, 79 insertions(+), 48 deletions(-)
--- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -329,26 +329,25 @@ static u32 hv_copyto_ringbuffer( * Get various debug metrics for the specified ring buffer * */ -void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, - struct hv_ring_buffer_debug_info *debug_info) +int hv_ringbuffer_get_debuginfo(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); + if (!ring_info->ring_buffer) + return -EINVAL;
- 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; - } + 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; }
/* --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -257,12 +257,16 @@ static ssize_t out_intr_mask_show(struct { 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); @@ -272,12 +276,15 @@ static ssize_t out_read_index_show(struc { 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); @@ -288,12 +295,15 @@ static ssize_t out_write_index_show(stru { 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); @@ -304,12 +314,15 @@ static ssize_t out_read_bytes_avail_show { 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); @@ -320,12 +333,15 @@ static ssize_t out_write_bytes_avail_sho { 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); @@ -335,12 +351,15 @@ static ssize_t in_intr_mask_show(struct { 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); @@ -350,12 +369,15 @@ static ssize_t in_read_index_show(struct { 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); @@ -365,12 +387,15 @@ static ssize_t in_write_index_show(struc { 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); @@ -381,12 +406,15 @@ static ssize_t in_read_bytes_avail_show( { 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); @@ -397,12 +425,15 @@ static ssize_t in_write_bytes_avail_show { 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); --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -580,8 +580,9 @@ int hv_ringbuffer_read(struct hv_ring_bu u32 offset, bool *signal);
-void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, - struct hv_ring_buffer_debug_info *debug_info); + +int hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, + struct hv_ring_buffer_debug_info *debug_info);
void hv_begin_read(struct hv_ring_buffer_info *rbi);