<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body><span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [CI][SHARDS] igt@* - dmesg-warn - BUG: unable to handle page fault for address"
href="https://bugs.freedesktop.org/show_bug.cgi?id=110778">bug 110778</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">Resolution</td>
<td>---
</td>
<td>FIXED
</td>
</tr>
<tr>
<td style="text-align:right;">Status</td>
<td>NEW
</td>
<td>RESOLVED
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [CI][SHARDS] igt@* - dmesg-warn - BUG: unable to handle page fault for address"
href="https://bugs.freedesktop.org/show_bug.cgi?id=110778#c3">Comment # 3</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [CI][SHARDS] igt@* - dmesg-warn - BUG: unable to handle page fault for address"
href="https://bugs.freedesktop.org/show_bug.cgi?id=110778">bug 110778</a>
from <span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span></b>
<pre>I suspect fixed by
commit f27a5d91201639161d6f6e25af1c89c9cbb3cac7 (drm-intel/topic/core-for-CI,
topic/core-for-CI)
Author: Hugh Dickins <<a href="mailto:hughd@google.com">hughd@google.com</a>>
Date: Wed May 29 09:25:40 2019 +0200
x86/fpu: Use fault_in_pages_writeable() for pre-faulting
Since commit
d9c9ce34ed5c8 ("x86/fpu: Fault-in user stack if
copy_fpstate_to_sigframe() fails")
we use get_user_pages_unlocked() to pre-faulting user's memory if a
write generates a pagefault while the handler is disabled.
This works in general and uncovered a bug as reported by Mike Rapoport.
It has been pointed out that this function may be fragile and a
simple pre-fault as in fault_in_pages_writeable() would be a better
solution. Better as in taste and simplicity: That write (as performed by
the alternative function) performs exactly the same faulting of memory
that we had before. This was suggested by Hugh Dickins and Andrew
Morton.
Use fault_in_pages_writeable() for pre-faulting of user's stack.
Fixes: d9c9ce34ed5c8 ("x86/fpu: Fault-in user stack if
copy_fpstate_to_sigframe() fails")
Suggested-by: Andrew Morton <<a href="mailto:akpm@linux-foundation.org">akpm@linux-foundation.org</a>>
Signed-off-by: Hugh Dickins <<a href="mailto:hughd@google.com">hughd@google.com</a>>
[bigeasy: patch description]
Signed-off-by: Sebastian Andrzej Siewior <<a href="mailto:bigeasy@linutronix.de">bigeasy@linutronix.de</a>>
but this might a different issue - time will tell.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the assignee for the bug.</li>
<li>You are the QA Contact for the bug.</li>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>