On 25/01/2022 14:15, Matthew Wilcox wrote:
Sure, but the pm8001 HW does has a 32b field, which is strange as the SAS
spec defines a 16b field in the task management Function information unit
"tag of task to be managed" field.
My point is that it's only safe because the pm8001 driver already limits
it to smaller than u16.
Seeing language like "should be enough" made
me think you'd just assumed that it would be.
I can update that wording to be confident that u16 is enough.
Seeing a line like:
u32 tag = 0xdeadbeef, rc = 0, n_elem = 0;
made me think it might not be; perhaps 0xdeadbeef was being used as
a flag value somewhere in the driver.
For example ...
drivers/scsi/pm8001/pm8001_hwi.c: int rc, tag = 0xdeadbeef;
drivers/scsi/pm8001/pm8001_sas.c: u32 tag = 0xdeadbeef, rc = 0, n_elem = 0;
drivers/scsi/pm8001/pm8001_sas.c: u32 tag = 0xdeadbeef;
drivers/scsi/pm8001/pm80xx_hwi.c: if (ibutton0 == 0xdeadbeef && ibutton1 == 0xdeadbeef) {
drivers/scsi/pm8001/pm80xx_hwi.c: int rc, tag = 0xdeadbeef;
That doesn't seem to be the case though; as far as I can tell the
tag value is never checked against 0xdeadbeef.
.
Right, 0xdeadbeef is initially assigned just as a safety measure.
Thanks,
John
