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authorStefan Richter <stefanr@s5r6.in-berlin.de>2007-08-11 11:52:08 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2007-10-16 23:59:55 +0200
commit261b5f664c6c68c5209656a71c41823eda0d938b (patch)
tree52045ab3beb1564b248a8389c241ac825b14c1bd
parentc4f3d41fed11c9050aa93bbaeed9f7f06bcc93ba (diff)
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ieee1394: sbp2: fix unsafe iteration over list of devices
sbp2_host_reset and sbp2_handle_status_write are not serialized against sbp2_alloc_device and sbp2_remove_device. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
-rw-r--r--drivers/ieee1394/sbp2.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index a81ba8fca0db..1b353b964b33 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -242,6 +242,8 @@ static int sbp2_max_speed_and_size(struct sbp2_lu *);
static const u8 sbp2_speedto_max_payload[] = { 0x7, 0x8, 0x9, 0xA, 0xB, 0xC };
+static DEFINE_RWLOCK(sbp2_hi_logical_units_lock);
+
static struct hpsb_highlevel sbp2_highlevel = {
.name = SBP2_DEVICE_NAME,
.host_reset = sbp2_host_reset,
@@ -732,6 +734,7 @@ static struct sbp2_lu *sbp2_alloc_device(struct unit_directory *ud)
struct sbp2_fwhost_info *hi;
struct Scsi_Host *shost = NULL;
struct sbp2_lu *lu = NULL;
+ unsigned long flags;
lu = kzalloc(sizeof(*lu), GFP_KERNEL);
if (!lu) {
@@ -784,7 +787,9 @@ static struct sbp2_lu *sbp2_alloc_device(struct unit_directory *ud)
lu->hi = hi;
+ write_lock_irqsave(&sbp2_hi_logical_units_lock, flags);
list_add_tail(&lu->lu_list, &hi->logical_units);
+ write_unlock_irqrestore(&sbp2_hi_logical_units_lock, flags);
/* Register the status FIFO address range. We could use the same FIFO
* for targets at different nodes. However we need different FIFOs per
@@ -828,16 +833,20 @@ static void sbp2_host_reset(struct hpsb_host *host)
{
struct sbp2_fwhost_info *hi;
struct sbp2_lu *lu;
+ unsigned long flags;
hi = hpsb_get_hostinfo(&sbp2_highlevel, host);
if (!hi)
return;
+
+ read_lock_irqsave(&sbp2_hi_logical_units_lock, flags);
list_for_each_entry(lu, &hi->logical_units, lu_list)
if (likely(atomic_read(&lu->state) !=
SBP2LU_STATE_IN_SHUTDOWN)) {
atomic_set(&lu->state, SBP2LU_STATE_IN_RESET);
scsi_block_requests(lu->shost);
}
+ read_unlock_irqrestore(&sbp2_hi_logical_units_lock, flags);
}
static int sbp2_start_device(struct sbp2_lu *lu)
@@ -919,6 +928,7 @@ alloc_fail:
static void sbp2_remove_device(struct sbp2_lu *lu)
{
struct sbp2_fwhost_info *hi;
+ unsigned long flags;
if (!lu)
return;
@@ -933,7 +943,9 @@ static void sbp2_remove_device(struct sbp2_lu *lu)
flush_scheduled_work();
sbp2util_remove_command_orb_pool(lu, hi->host);
+ write_lock_irqsave(&sbp2_hi_logical_units_lock, flags);
list_del(&lu->lu_list);
+ write_unlock_irqrestore(&sbp2_hi_logical_units_lock, flags);
if (lu->login_response)
dma_free_coherent(hi->host->device.parent,
@@ -1707,6 +1719,7 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
}
/* Find the unit which wrote the status. */
+ read_lock_irqsave(&sbp2_hi_logical_units_lock, flags);
list_for_each_entry(lu_tmp, &hi->logical_units, lu_list) {
if (lu_tmp->ne->nodeid == nodeid &&
lu_tmp->status_fifo_addr == addr) {
@@ -1714,6 +1727,8 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
break;
}
}
+ read_unlock_irqrestore(&sbp2_hi_logical_units_lock, flags);
+
if (unlikely(!lu)) {
SBP2_ERR("lu is NULL - device is gone?");
return RCODE_ADDRESS_ERROR;