Usually this error occurs when the allocator has been told a capability is free when it actually isn't. This is usually due to a capability being duplicated and only one copy being deleted. The error you are seeing is the allocator attempting to use a slot that it thinks is free but is actually not.

One approach is to debugging this issue is to not free anything, and slowly re-add calls to free until you find the culprit. You can also use seL4_DebugCapIdentify to test what type of capability it is.

From: Devel <devel-bounces@sel4.systems> on behalf of Richard Clark <rclark@i-a-i.com>
Sent: Wednesday, 21 February 2018 6:39 AM
To: devel@sel4.systems
Subject: [seL4] split.c bootstrap.c failure?

Hi!

What is this error and how might I go about tracking down the cause?

<<seL4(CPU 0) [decodeUntypedInvocation/167 T0xe0792100 "csm-threads" @3a98c]: Untyped Retype: Slot #15 in destination window non-empty.>>

_refill_pool@split.c:177 Failed to retype untyped, error 8

vka_alloc_object_at_maybe_dev@object.h:59 Failed to allocate object of size 4096, error 1

alloc_and_map@bootstrap.c:103 Failed to allocate bootstrap frame, error: 1

What I’ve done, is taken over the usual sel4test process and turned it into a little process that starts a few others.

This error occurs at near the beginning of the main process, after it has allocated some untyped space for a secondary process,

and just started it running. There is tons of memory available everywhere, and I do not understand why this is failing…. clues?

Thanks!

Richard H. Clark

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