From: Jason Wessel <jason.wessel@windriver.com>
Date: Fri, 10 Aug 2012 17:21:15 +0000 (-0500)
Subject: mips,kgdb: fix recursive page fault with CONFIG_KPROBES
X-Git-Tag: v3.2.33~63
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3029c7814c046543125da61095eecefb446e9e42;p=pandora-kernel.git

mips,kgdb: fix recursive page fault with CONFIG_KPROBES

commit f0a996eeeda214f4293e234df33b29bec003b536 upstream.

This fault was detected using the kgdb test suite on boot and it
crashes recursively due to the fact that CONFIG_KPROBES on mips adds
an extra die notifier in the page fault handler.  The crash signature
looks like this:

kgdbts:RUN bad memory access test
KGDB: re-enter exception: ALL breakpoints killed
Call Trace:
[<807b7548>] dump_stack+0x20/0x54
[<807b7548>] dump_stack+0x20/0x54

The fix for now is to have kgdb return immediately if the fault type
is DIE_PAGE_FAULT and allow the kprobe code to decide what is supposed
to happen.

Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

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