PANIC: Unexpected exception "General Protection Exception" occurred in kernel mode!

[darfo]

KDL appears when booting x86_64 hrev48926 on real hardware, Toshiba C640 laptop with 2 core Celeron Wifi is is Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) (rev 01)

Attached is KDL and ints

System start getting real hot even though fan is running max. System shuts self off after about 20secs.

[darfo]

KDL

[darfo]

ints command output

[streak]

The same thing on my NOKIA BOOKLET 3G occurs. Previously it worked.

[streak]

i just checked that on hrev48752 atheros wifi works perfectly on Nokia Booklet 3G so between 48752 and 48926 something was changed and wifi stopped to work.

[korli]

Why do you say "KDL in atheroswifi"?

[darfo]

Argh. The first KDL pictures I took on my cellphone were in atherowife but I decided they were too hard to read. Got out my camera and took pictures of what I thought was the same error. Good thing I don't work for NASA. I will try to get the correct pictures.

[darfo]

Got the pictures but it took two tries and showed an interesting clue. I'm using a dual-boot system. When I powered up, booted linux, shutdown, and then booted Haiku it worked fine and I was able to connect the wifi fine.

When I powered off and then booted straight into Haiku the KDL happened. Please see KDL2.png and ints2.png.

[darfo]

The real KDL <blush>

[darfo]

The real ints </blush>

[diver]

Do you get the same KDL with gcc2hybrid builds?

[korli]

Please a syslog.

[darfo]

The system never comes up far enough to file the syslog into the file system so all I can offer is the tail of the KDL syslog output. When I mount the filesystem on Linux the log file is empty.

It will take me some time to build a gcc2hybrid but I will start on it and report back the results.

[darfo]

tail of KDL syslog after General Protection Error

[darfo]

The error does not occur with gcc2hybrid. The Atheros wifi works fine.

[korli]

Thanks, a syslog with gcc2hybrid would be useful anyway.

[darfo]

After successful gcc2hybrid boot with Atheros wifi enabled

[korli]

vendor 168c: Qualcomm Atheros
device 002b: AR9285 Wireless Network Adapter (PCI-Express)
...
x86_gcc2 [atheroswifi] (ath_pci) bus_alloc_resource(1, [0], 0x0, 0xffffffff, 0x1,0x6)
x86_64 [atheroswifi] (ath_pci) bus_alloc_resource(3, [16], 0x0, 0xffffffffffffffff, 0x1,0x2)
[atheroswifi] [ath] AR9285E_20 detected; using XE TX gain tables

[streak]

On my Nokia Booklet 3G with poulsbo and atheros onboard, on GCC2H not booting so the bug it is still present, there.

[diver]

streak, please open a new ticket, your issue doesn't seem to be related to this one.

[simonsouth]

From looking at the disassembly it seems the problem happens in getchannels at ​ath_regdomain.c:549 when the driver tries to zero-out a 16-byte ieee80211_channel structure in the array passed to it:

OS_MEMZERO(ic, sizeof(*ic));

The actual exception occurs in memset_small at ​x86_64/arch_string.cpp:188 when writing to memory, so presumably ic is invalid at this point.

All the code that sets up the channel array seems to be contained in the driver itself though, and I can't find in ​the FreeBSD bug tracker anyone reporting a similar problem on that platform, so the root cause probably lies in some Haiku-specific code elsewhere.

I'm tempted to finger memset_small (especially since the driver works on other architectures) except ​the code is so simple it's hard to see how there could be a problem with it.

I'm convinced now this is not a stack-alignment issue (#10509), anyway.

[waddlesplash]

Please retest with a recent nightly; the atheroswifi driver has been upgraded and a number of bugs in the WiFi stack fixed.

[darfo]

Retested on nightly hrev52328-x86_64 with the same hardware. Works great. Good job!

[waddlesplash]

Yay!