kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Drivers: hv: ring_buffer: use wrap around mappings in hv_copy{from, to}_ringbuffer()

Browse source 
With wrap around mappings for ring buffers we can always use a single
memcpy() to do the job.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vitaly Kuznetsov 2016-09-02 05:58:21 -07:00 committed by Greg Kroah-Hartman
parent 9988ce6856
commit f24f0b495b
1 changed files with 2 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
drivers/hv/ring_buffer.c
View file

@ -172,18 +172,7 @@ static u32 hv_copyfrom_ringbuffer(
void *ring_buffer = hv_get_ring_buffer(ring_info);
u32 ring_buffer_size = hv_get_ring_buffersize(ring_info);
u32 frag_len;
/* wrap-around detected at the src */
if (destlen > ring_buffer_size - start_read_offset) {
frag_len = ring_buffer_size - start_read_offset;
memcpy(dest, ring_buffer + start_read_offset, frag_len);
memcpy(dest + frag_len, ring_buffer, destlen - frag_len);
} else
memcpy(dest, ring_buffer + start_read_offset, destlen);
memcpy(dest, ring_buffer + start_read_offset, destlen);
start_read_offset += destlen;
start_read_offset %= ring_buffer_size;
@ -204,15 +193,8 @@ static u32 hv_copyto_ringbuffer(
{
void *ring_buffer = hv_get_ring_buffer(ring_info);
u32 ring_buffer_size = hv_get_ring_buffersize(ring_info);
u32 frag_len;
/* wrap-around detected! */
if (srclen > ring_buffer_size - start_write_offset) {
frag_len = ring_buffer_size - start_write_offset;
memcpy(ring_buffer + start_write_offset, src, frag_len);
memcpy(ring_buffer, src + frag_len, srclen - frag_len);
} else
memcpy(ring_buffer + start_write_offset, src, srclen);
memcpy(ring_buffer + start_write_offset, src, srclen);
start_write_offset += srclen;
start_write_offset %= ring_buffer_size;