diff options
Diffstat (limited to 'drivers/target/loopback/tcm_loop.c')
| -rw-r--r-- | drivers/target/loopback/tcm_loop.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c index aa2d6799723..fb85b35bd2f 100644 --- a/drivers/target/loopback/tcm_loop.c +++ b/drivers/target/loopback/tcm_loop.c @@ -174,6 +174,24 @@ static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd) sgl_bidi = sdb->table.sgl; sgl_bidi_count = sdb->table.nents; } + /* + * Because some userspace code via scsi-generic do not memset their + * associated read buffers, go ahead and do that here for type + * SCF_SCSI_CONTROL_SG_IO_CDB. Also note that this is currently + * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB + * by target core in transport_generic_allocate_tasks() -> + * transport_generic_cmd_sequencer(). + */ + if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB && + se_cmd->data_direction == DMA_FROM_DEVICE) { + struct scatterlist *sg = scsi_sglist(sc); + unsigned char *buf = kmap(sg_page(sg)) + sg->offset; + + if (buf != NULL) { + memset(buf, 0, sg->length); + kunmap(sg_page(sg)); + } + } /* Tell the core about our preallocated memory */ ret = transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc), |