Re: [PATCH] bfa: fix access to bfad_im_port_s
From: Johannes Thumshirn
Date: Wed Dec 06 2017 - 03:08:10 EST
James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> writes:
> On Tue, 2017-11-28 at 16:26 +0100, Johannes Thumshirn wrote:
>> Commit 'cd21c605b2cf ("scsi: fc: provide fc_bsg_to_shost() helper")'
>> changed access to bfa's 'struct bfad_im_port_s' by using shost_priv()
>> instead of shost->hostdata[0].
>>
>> This lead to crashes like in the following back-trace:
>>
>> task: ffff880046375300 ti: ffff8800a2ef8000 task.ti: ffff8800a2ef8000
>> RIP: e030:[<ffffffffa04c8252>]ÂÂ[<ffffffffa04c8252>]
>> bfa_fcport_get_attr+0x82/0x260 [bfa]
>> RSP: e02b:ffff8800a2efba10ÂÂEFLAGS: 00010046
>> RAX: 575f415441536432 RBX: ffff8800a2efba28 RCX: 0000000000000000
>> RDX: 0000000000000000 RSI: ffff8800a2efba28 RDI: ffff880004dc31d8
>> RBP: ffff880004dc31d8 R08: 0000000000000000 R09: 0000000000000001
>> R10: ffff88011fadc468 R11: 0000000000000001 R12: ffff880004dc31f0
>> R13: 0000000000000200 R14: ffff880004dc61d0 R15: ffff880004947a10
>> FS:ÂÂ00007feb1e489700(0000) GS:ffff88011fac0000(0000)
>> knlGS:0000000000000000
>> CS:ÂÂe033 DS: 0000 ES: 0000 CR0: 000000008005003b
>> CR2: 00007ffe14e46c10 CR3: 00000000957b8000 CR4: 0000000000000660
>> Stack:
>> Âffff88001d4da000 ffff880004dc31c0 ffffffffa048a9df ffffffff81e56380
>> Â0000000000000000 0000000000000000 0000000000000000 0000000000000000
>> [] bfad_iocmd_ioc_get_info+0x4f/0x220 [bfa]
>> [] bfad_iocmd_handler+0xa00/0xd40 [bfa]
>> [] bfad_im_bsg_request+0xee/0x1b0 [bfa]
>> [] fc_bsg_dispatch+0x10b/0x1b0 [scsi_transport_fc]
>> [] bsg_request_fn+0x11d/0x1c0
>> [] __blk_run_queue+0x2f/0x40
>> [] blk_execute_rq_nowait+0xa8/0x160
>> [] blk_execute_rq+0x77/0x120
>> [] bsg_ioctl+0x1b6/0x200
>> [] do_vfs_ioctl+0x2cd/0x4a0
>> [] SyS_ioctl+0x74/0x80
>> [] entry_SYSCALL_64_fastpath+0x12/0x6d
>>
>> Fixes: cd21c605b2cf ("scsi: fc: provide fc_bsg_to_shost() helper")
>> Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
>> Cc: Michal Koutnà <mkoutny@xxxxxxxx>
>> ---
>> Âdrivers/scsi/bfa/bfad_bsg.c | 6 ++++--
>> Â1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/scsi/bfa/bfad_bsg.c
>> b/drivers/scsi/bfa/bfad_bsg.c
>> index 72ca2a2e08e2..09ef68c8225f 100644
>> --- a/drivers/scsi/bfa/bfad_bsg.c
>> +++ b/drivers/scsi/bfa/bfad_bsg.c
>> @@ -3135,7 +3135,8 @@ bfad_im_bsg_vendor_request(struct bsg_job *job)
>> Â struct fc_bsg_request *bsg_request = job->request;
>> Â struct fc_bsg_reply *bsg_reply = job->reply;
>> Â uint32_t vendor_cmd = bsg_request-
>> >rqst_data.h_vendor.vendor_cmd[0];
>> - struct bfad_im_port_s *im_port =
>> shost_priv(fc_bsg_to_shost(job));
>> + struct Scsi_Host *shost = fc_bsg_to_shost(job);
>> + struct bfad_im_port_s *im_port = shost->hostdata[0];
>> Â struct bfad_s *bfad = im_port->bfad;
>> Â void *payload_kbuf;
>> Â int rc = -EINVAL;
>> @@ -3350,7 +3351,8 @@ int
>> Âbfad_im_bsg_els_ct_request(struct bsg_job *job)
>> Â{
>> Â struct bfa_bsg_data *bsg_data;
>> - struct bfad_im_port_s *im_port =
>> shost_priv(fc_bsg_to_shost(job));
>> + struct Scsi_Host *shost = fc_bsg_to_shost(job);
>> + struct bfad_im_port_s *im_port = shost->hostdata[0];
>> Â struct bfad_s *bfad = im_port->bfad;
>> Â bfa_bsg_fcpt_t *bsg_fcpt;
>> Â struct bfad_fcxpÂÂÂÂ*drv_fcxp;
>
> OK, so we had a linux next failure with this:
>
> After merging the scsi tree, today's linux-next build (x86_64
> allmodconfig) produced these warnings:
>
> drivers/scsi/bfa/bfad_bsg.c: In function 'bfad_im_bsg_vendor_request':
> drivers/scsi/bfa/bfad_bsg.c:3137:35: warning: initialization makes pointer from integer without a cast [-Wint-conversion]
> struct bfad_im_port_s *im_port = shost->hostdata[0];
> ^
> drivers/scsi/bfa/bfad_bsg.c: In function 'bfad_im_bsg_els_ct_request':
> drivers/scsi/bfa/bfad_bsg.c:3353:35: warning: initialization makes pointer from integer without a cast [-Wint-conversion]
> struct bfad_im_port_s *im_port = shost->hostdata[0];
> ^
>
> Introduced by commit
>
> 45349821ab3a ("scsi: bfa: fix access to bfad_im_port_s")
>
> --
> Cheers,
> Stephen Rothwell
>
> The reason is you should be using shost_priv(shost) not shost->hostdata[0].
Yes, but using shost_priv() was resulting in the crash beforehand.
shost_priv() doesn't do the same actually:
static inline void *shost_priv(struct Scsi_Host *shost)
{
return (void *)shost->hostdata;
}
vs
shost->hostdata[0];
and:
drivers/scsi/bfa/bfad_im.c:567: im_port->shost->hostdata[0] = (unsigned
long)im_port;
The quick fix would be:
diff --git a/drivers/scsi/bfa/bfad_bsg.c b/drivers/scsi/bfa/bfad_bsg.c
index 09ef68c8225f..075185db533f 100644
--- a/drivers/scsi/bfa/bfad_bsg.c
+++ b/drivers/scsi/bfa/bfad_bsg.c
@@ -3136,7 +3136,7 @@ bfad_im_bsg_vendor_request(struct bsg_job *job)
struct fc_bsg_reply *bsg_reply = job->reply;
uint32_t vendor_cmd = bsg_request->rqst_data.h_vendor.vendor_cmd[0];
struct Scsi_Host *shost = fc_bsg_to_shost(job);
- struct bfad_im_port_s *im_port = shost->hostdata[0];
+ struct bfad_im_port_s *im_port = (struct bfad_im_port_s *) shost->hostdata[0];
struct bfad_s *bfad = im_port->bfad;
void *payload_kbuf;
int rc = -EINVAL;
@@ -3352,7 +3352,7 @@ bfad_im_bsg_els_ct_request(struct bsg_job *job)
{
struct bfa_bsg_data *bsg_data;
struct Scsi_Host *shost = fc_bsg_to_shost(job);
- struct bfad_im_port_s *im_port = shost->hostdata[0];
+ struct bfad_im_port_s *im_port = (struct bfad_im_port_s *) shost->hostdata[0];
struct bfad_s *bfad = im_port->bfad;
bfa_bsg_fcpt_t *bsg_fcpt;
struct bfad_fcxp *drv_fcxp;
Which is also consistent with the rest of the driver.
Johannes
--
Johannes Thumshirn Storage
jthumshirn@xxxxxxx +49 911 74053 689
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