On 07/12/2017 02:51 AM, [email protected] wrote: > From: Xiubo Li <[email protected]> > > For most case the sg->length equals to PAGE_SIZE, so this bug won't > be triggered. Otherwise this will crash the kernel, for example when > all segments' sg->length equal to 1K. > > Signed-off-by: Xiubo Li <[email protected]> > --- > drivers/target/target_core_user.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/drivers/target/target_core_user.c > b/drivers/target/target_core_user.c > index 8bf0823..9030c2a 100644 > --- a/drivers/target/target_core_user.c > +++ b/drivers/target/target_core_user.c > @@ -590,8 +590,6 @@ static int scatter_data_area(struct tcmu_dev *udev, > block_remaining); > to_offset = get_block_offset_user(udev, dbi, > block_remaining); > - offset = DATA_BLOCK_SIZE - block_remaining; > - to += offset; > > if (*iov_cnt != 0 && > to_offset == iov_tail(*iov)) { > @@ -602,8 +600,10 @@ static int scatter_data_area(struct tcmu_dev *udev, > (*iov)->iov_len = copy_bytes; > } > if (copy_data) { > - memcpy(to, from + sg->length - sg_remaining, > - copy_bytes); > + offset = DATA_BLOCK_SIZE - block_remaining; > + memcpy(to + offset, > + from + sg->length - sg_remaining, > + copy_bytes); > tcmu_flush_dcache_range(to, copy_bytes); > } > sg_remaining -= copy_bytes; > @@ -664,9 +664,8 @@ static void gather_data_area(struct tcmu_dev *udev, > struct tcmu_cmd *cmd, > copy_bytes = min_t(size_t, sg_remaining, > block_remaining); > offset = DATA_BLOCK_SIZE - block_remaining; > - from += offset; > tcmu_flush_dcache_range(from, copy_bytes); > - memcpy(to + sg->length - sg_remaining, from, > + memcpy(to + sg->length - sg_remaining, from + offset, > copy_bytes); > > sg_remaining -= copy_bytes; >
Nice. Reviewed-by: Mike Christie <[email protected]>
