KDL: SMAP violation in usb_disk

[Berusik]

after dd on foto kernel panic, and command on Terminal

[korli]

Which revision? I'm unsure which component is at fault here.

[Berusik]

52635

[waddlesplash]

I'm unsure which component is at fault here.

It seems we have taken the convention of handling user buffers in the drivers themselves (personally I think doing it in common_user_io makes more sense), so then usb_disk would be the thing to change here.

[korli]

In scsi_disk at least, this is done in a IORequest, which nicely handles VM operations when needed. Might also be a good idea to introduce the IOScheduler in usb_disk.

For this specific bug then, usb_disk needs a bounce buffer for any user I/O requests.

[kallisti5]

I was running over this, and found some interesting observations:

Haiku x86_64, hrev52726, UEFI booted. USB 2.0

dd if=haiku-nightly-anyboot.iso of=/dev/disk/usb/0/0/raw bs=2M

No problems.

Haiku x86_64, hrev52775, UEFI booted, USB 3.0

BFS on USB 3.0 flash drive mounted at /TEST/
dd if=/dev/zero of=/TEST/test status=progress oflag=direct

KDL. (uploading soon)

[kallisti5]

hrev52775 XHCI dd

[waddlesplash]

Actually it seems the USB stack already handles userland areas: ​http://xref.plausible.coop/source/xref/haiku/src/add-ons/kernel/bus_managers/usb/Transfer.cpp#136

It just doesn't do it when the kernel passes buffers in. So, we should modify this code to accept user buffers from the kernel, too.

[waddlesplash]

It was actually a bug in XHCI itself. Fixed in hrev52826.

[nielx]

Assign tickets with status=closed and resolution=fixed within the R1/beta2 development window to the R1/beta2 Milestone