KDL: SMAP violation (sshfs_fuse)

[diver]

hrev52597.

To reproduce:

pkgman ins ssh_fuse
mkdir /mnt
echo password | /system/servers/userlandfs_server sshfs

In another console:

mount -t userlandfs -o 'sshfs user@server:./ -o password_stdin' /mnt

Double click newly mounted volume on the Desktop.

[waddlesplash]

I'm not sure why this ticket is assigned to me...

Anyway, I've seen the "read fault" in a backtrace only once before, in a KDL in the USB MIDI driver. Any other evidence of it? Because i have no idea where to begin investigating that.

[korli]

diver, you can probably give more information:

Here is the help for the area debugger command: ​https://github.com/haiku/haiku/blob/9cc0f06a015202f58ae669f0bf7653e66161d7e2/src/system/kernel/vm/vm.cpp#L3319

"area contains <address>" should show which area is causing SMAP to trigger.

Thanks!

[diver]

Since I didn't know what address to use I used both from the panic message.

[korli]

See ​https://github.com/haiku/haiku/blob/master/src/add-ons/kernel/file_systems/userlandfs/private/Requests.cpp#L470

It should probably be B_KERNEL_READ_AREA instead of B_READ_AREA.

[diver]

Thanks! I only needed to add #include <vm/vm.h> to make it to compile with jam userland_fs.hpkg and now it works just fine!

[korli]

Posted the change here: ​https://review.haiku-os.org/#/c/haiku/+/737/

[axeld]

Please try again with hrev52604 or later.

[diver]

Listing files works now, however trying to open a file results in another crash.

[korli]

Isn't there a complete stack trace?

[diver]

Unfortunately no, stack trace just suddenly ends with [*** READ/WIRITE FAULT (?)]. Running bt about 5 times simply reboots VMware VM.

[korli]

Please check with hrev52612 or newer.

About the stacktrace, I disabled locally print_demangled_call() in src/system/kernel/arch/x86/arch_debug.cpp to workaround the effect of SMAP. Needs more investigation.

[diver]

Confirmed fixed. Thanks!

[korli]

For reference, the follow-up on the stacktrace problem is ​https://review.haiku-os.org/#/c/haiku/+/742/ (not SMAP related after all).

[nielx]

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