Bug #1846

page fault in AcpiExReleaseMutex

Added by eocallaghan almost 4 years ago. Updated almost 4 years ago.

Status:ClosedStart date:
Priority:HighDue date:
Assignee:eocallaghan% Done:

0%

Category:-
Target version:-

Description

One can course DF to panic if one presses a function key to turn on wifi during
early boot, putting debug.acpi.disabled="ec" in /boot/loader.conf stops the panic.

http://www.freebsd.org/cgi/query-pr.cgi?pr=140979

Apparently this is fixed in the upstream ACPICA, so we just need to resync

exmutex.c.patch Magnifier (6.95 KB) eocallaghan, 09/19/2010 04:25 AM

History

#1 Updated by eocallaghan almost 4 years ago

The problem is with the AML Mutex handling function AcpiExReleaseMutex where the
function can fault under the very rare condition when the interpreter has
blocked, the interpreter lock is released, the interpreter is then reentered via
the same thread, and attempts to acquire an AML mutex that was previously acquired.

This is indeed fixed in the acpica-unix-20100806 snapshot.

#2 Updated by eocallaghan almost 4 years ago

Attached is the required fix from the acpica-unix-20100806 snapshot;
Please review and commit.

#3 Updated by eocallaghan almost 4 years ago

Fix delivered in commit 920c7d82e6a0b17caf88ae20355adbc230efd09b.

Cheers,
Edward.

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