kernel crashes on binary possibly containing ARMv7 opcodes

[Jonathan Schleifer]

When launching the following binary, the kernel crashes:
https://webkeks.org/crash_kernel.gz

This binary *does* contain the ARMv7 opcode movw, however, a version without this opcode shows the same behaviour.

This binary was simply produced by compiling ObjFW using Clang 3.1 (built from source, as the Clang included in Raspbian is broken - but this is another bug).

[Jonathan Schleifer (midar)]

Oh, FWIW, I started it in gdb and set a breakpoint on main - it is never even reached, the kernel crashes even before that, most likely because of an __attribute__((constructor)). I haven't found a way yet to break on the entry point and single step from there.

[peter green (plugwash)]

Is this still reproducable with a recent kernel? (and if so what kernel exactly?)

[Jonathan Schleifer (midar)]

Yes, this is still happening with 3.6.11+. Just download the linked executable (I still host it there), gunzip it, chmod +x it, run it and see your kernel crash. All it does is issue invalid opcodes. The kernel does not send a SIGILL like it is supposed to, but instead choses to crash.

[peter green (plugwash)]

Have you reported this to the raspberry pi foundation kernel guys? (iirc they track their bugs on github)

[Diederik (didi-debian)]

As peter green already indicated, it should be reported at: https://github.com/raspberrypi/linux/issues/

As this is not a raspbian.org bug, I'm marking it as invalid.