From a50da144d048f9dbebed2b1441ed779d6bbbcd03 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 7 Sep 2012 17:30:40 +0200 Subject: target: support zero allocation length in SBC commands READ CAPACITY must be subject to the same treatment as INQUIRY, REQUEST SENSE, and MODE SENSE, but there are no pre-existing bugs to fix here. Just use an on-stack buffer, and copy to it after checking the return value of transport_kmap_data_sg. Signed-off-by: Paolo Bonzini Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_sbc.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'drivers/target/target_core_sbc.c') diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index a9dd9469e3b..868f8aa04f1 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -40,8 +40,9 @@ static int sbc_emulate_readcapacity(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; - unsigned char *buf; unsigned long long blocks_long = dev->transport->get_blocks(dev); + unsigned char *rbuf; + unsigned char buf[8]; u32 blocks; if (blocks_long >= 0x00000000ffffffff) @@ -49,8 +50,6 @@ static int sbc_emulate_readcapacity(struct se_cmd *cmd) else blocks = (u32)blocks_long; - buf = transport_kmap_data_sg(cmd); - buf[0] = (blocks >> 24) & 0xff; buf[1] = (blocks >> 16) & 0xff; buf[2] = (blocks >> 8) & 0xff; @@ -60,7 +59,11 @@ static int sbc_emulate_readcapacity(struct se_cmd *cmd) buf[6] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff; buf[7] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff; - transport_kunmap_data_sg(cmd); + rbuf = transport_kmap_data_sg(cmd); + if (rbuf) { + memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length)); + transport_kunmap_data_sg(cmd); + } target_complete_cmd(cmd, GOOD); return 0; @@ -69,11 +72,11 @@ static int sbc_emulate_readcapacity(struct se_cmd *cmd) static int sbc_emulate_readcapacity_16(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; - unsigned char *buf; + unsigned char *rbuf; + unsigned char buf[32]; unsigned long long blocks = dev->transport->get_blocks(dev); - buf = transport_kmap_data_sg(cmd); - + memset(buf, 0, sizeof(buf)); buf[0] = (blocks >> 56) & 0xff; buf[1] = (blocks >> 48) & 0xff; buf[2] = (blocks >> 40) & 0xff; @@ -93,7 +96,11 @@ static int sbc_emulate_readcapacity_16(struct se_cmd *cmd) if (dev->se_sub_dev->se_dev_attrib.emulate_tpu || dev->se_sub_dev->se_dev_attrib.emulate_tpws) buf[14] = 0x80; - transport_kunmap_data_sg(cmd); + rbuf = transport_kmap_data_sg(cmd); + if (rbuf) { + memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length)); + transport_kunmap_data_sg(cmd); + } target_complete_cmd(cmd, GOOD); return 0; -- cgit v1.2.3