linux.git/drivers/target/target_core_user.c, branch v4.14

tcmu: free old string on reconfig

2017-07-30T22:23:21+00:00

On initial tcmu_configure_device call the info->name would
have already been allocated and set, so on the second call
make sure to free it first.

Reported-by: Mike Christie 
Reviewed-by: Mike Christie 
Signed-off-by: Bryant G. Ly 
Signed-off-by: Nicholas Bellinger

tcmu: Fix possible to/from address overflow when doing the memcpy

2017-07-30T22:12:32+00:00

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 
Reviewed-by: Mike Christie 
Signed-off-by: Nicholas Bellinger

tcmu: clean up the code and with one small fix

2017-07-11T17:48:07+00:00

Remove useless blank line and code and at the same time add one error
path to catch the errors.

Reviewed-by: Mike Christie 
Signed-off-by: Xiubo Li 
Signed-off-by: Nicholas Bellinger

tcmu: Fix possbile memory leak / OOPs when recalculating cmd base size

2017-07-11T17:47:58+00:00

For all the entries allocated from the ring cmd area, the memory is
something like the stack memory, which will always reserve the old
data, so the entry->req.iov_bidi_cnt maybe none zero.

On some environments, the crash could be reproduce very easy and some
not. The following is the crash core trace as reported by Damien:

[  240.143969] CPU: 0 PID: 1285 Comm: iscsi_trx Not tainted 4.12.0-rc1+ #3
[  240.150607] Hardware name: ASUS All Series/H87-PRO, BIOS 2104 10/28/2014
[  240.157331] task: ffff8807de4f5800 task.stack: ffffc900047dc000
[  240.163270] RIP: 0010:memcpy_erms+0x6/0x10
[  240.167377] RSP: 0018:ffffc900047dfc68 EFLAGS: 00010202
[  240.172621] RAX: ffffc9065db85540 RBX: ffff8807f7980000 RCX: 0000000000000010
[  240.179771] RDX: 0000000000000010 RSI: ffff8807de574fe0 RDI: ffffc9065db85540
[  240.186930] RBP: ffffc900047dfd30 R08: ffff8807de41b000 R09: 0000000000000000
[  240.194088] R10: 0000000000000040 R11: ffff8807e9b726f0 R12: 00000006565726b0
[  240.201246] R13: ffffc90007612ea0 R14: 000000065657d540 R15: 0000000000000000
[  240.208397] FS:  0000000000000000(0000) GS:ffff88081fa00000(0000) knlGS:0000000000000000
[  240.216510] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  240.222280] CR2: ffffc9065db85540 CR3: 0000000001c0f000 CR4: 00000000001406f0
[  240.229430] Call Trace:
[  240.231887]  ? tcmu_queue_cmd+0x83c/0xa80
[  240.235916]  ? target_check_reservation+0xcd/0x6f0
[  240.240725]  __target_execute_cmd+0x27/0xa0
[  240.244918]  target_execute_cmd+0x232/0x2c0
[  240.249124]  ? __local_bh_enable_ip+0x64/0xa0
[  240.253499]  iscsit_execute_cmd+0x20d/0x270
[  240.257693]  iscsit_sequence_cmd+0x110/0x190
[  240.261985]  iscsit_get_rx_pdu+0x360/0xc80
[  240.267565]  ? iscsi_target_rx_thread+0x54/0xd0
[  240.273571]  iscsi_target_rx_thread+0x9a/0xd0
[  240.279413]  kthread+0x113/0x150
[  240.284120]  ? iscsi_target_tx_thread+0x1e0/0x1e0
[  240.290297]  ? kthread_create_on_node+0x40/0x40
[  240.296297]  ret_from_fork+0x2e/0x40
[  240.301332] Code: 90 90 90 90 90 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48
c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48
89 d1  a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38
[  240.321751] RIP: memcpy_erms+0x6/0x10 RSP: ffffc900047dfc68
[  240.328838] CR2: ffffc9065db85540
[  240.333667] ---[ end trace b7e5354cfb54d08b ]---

To fix this, just memset all the entry memory before using it, and
also to be more readable we adjust the bidi code.

Fixed: fe25cc34795(tcmu: Recalculate the tcmu_cmd size to save cmd area
		memories)
Reported-by: Bryant G. Ly 
Tested-by: Bryant G. Ly 
Reported-by: Damien Le Moal 
Tested-by: Damien Le Moal 
Reviewed-by: Mike Christie 
Signed-off-by: Xiubo Li 
Cc:  # 4.12+
Signed-off-by: Nicholas Bellinger

tcmu: Fix dev_config_store

2017-07-10T03:57:56+00:00

Currently when there is a reconfig, the uio_info->name
does not get updated to reflect the change in the dev_config
name change.

On restart tcmu-runner there will be a mismatch between
the dev_config string in uio and the tcmu structure that contains
the string. When this occurs it'll reload the one in uio
and you lose the reconfigured device path.

v2: Created a helper function for the updating of uio_info

Signed-off-by: Bryant G. Ly 
Signed-off-by: Nicholas Bellinger

tcmu: fix sense handling during completion

2017-07-07T06:11:46+00:00

We were just copying the sense to the cmd sense_buffer and
did not implement a transport_complete or set the
SCF_TRANSPORT_TASK_SENSE, so the sense was ignored.

Signed-off-by: Mike Christie 
Signed-off-by: Nicholas Bellinger

tcmu: Fix flushing cmd entry dcache page

2017-07-07T06:11:43+00:00

When feeding the tcmu's cmd ring, we need to flush the dcache page
for the cmd entry to make sure these kernel stores are visible to
user space mappings of that page.

For the none PAD cmd entry, this will be flushed at the end of the
tcmu_queue_cmd_ring().

Signed-off-by: Xiubo Li 
Reviewed-by: Mike Christie 
Signed-off-by: Nicholas Bellinger

tcmu: fix multiple uio open/close sequences

2017-07-07T06:11:42+00:00

If the uio device is open and closed multiple times, the
kref count will be off due to tcmu_release getting called
multiple times for each close. This patch integrates
Wenji Tang's patch to add a kref_get on open that now
matches the kref_put done on tcmu_release and adds
a kref_put in tcmu_destroy_device to match the kref_get
done in succesful tcmu_configure_device calls.

Signed-off-by: Mike Christie 
Cc: Wenji Tang 
Signed-off-by: Nicholas Bellinger

tcmu: drop configured check in destroy

2017-07-07T06:11:41+00:00

destroy_device is only called if we have successfully run
configure_device, so drop the duplicate tcmu_dev_configured check.

Signed-off-by: Mike Christie 
Signed-off-by: Nicholas Bellinger

tcmu: perfom device add, del and reconfig synchronously

2017-07-07T06:11:39+00:00

This makes the device add, del reconfig operations sync. It fixes
the issue where for add and reconfig, we do not know if userspace
successfully completely the operation, so we leave invalid kernel
structs or report incorrect status for the config/reconfig operations.

Signed-off-by: Mike Christie 
Signed-off-by: Nicholas Bellinger