Messages in this thread | | | Subject | Re: [BUG] 3.4.109 - unable to handle kernel NULL pointer dereference at (null) | From | Zefan Li <> | Date | Thu, 8 Oct 2015 14:17:30 +0800 |
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(back from vacation)
On 2015/10/4 12:26, Cal Peake wrote: > On Thu, 1 Oct 2015, Steven Rostedt wrote: > >> >> I merged 3.4.109 into 3.4-rt, and it bugged. I then booted 3.4.109 >> vanilla and it bugged too. 3.4.108 is fine. >> >
I guess this is caused by the following commit, which has already been reverted in mainline kernel. I'll fix it in 3.4.110.
drm/i915: Don't skip request retirement if the active list is empty commit 0aedb1626566efd72b369c01992ee7413c82a0c5 upstream.
> I'm getting a similar type bug here. I've bisected it down to this commit: > > commit 961bd13539b9e7ca5d2e667668141496b7a1d6bc > Author: Michel Dänzer <michel.daenzer@amd.com> > Date: Thu Apr 16 11:17:27 2015 +0900 > > drm/radeon: Use drm_calloc_ab for CS relocs > > commit b421ed15d2c3039eb724680e4de1e4b2bd196a9a upstream. > > The number of relocs is passed in by userspace and can be large. It has > been observed to cause kcalloc failures in the wild. > > > Backing it out of vanilla 3.4.109 has so far eliminated the problem. >
As you and Satoshi-san have already found out the culprit, I'll just revert it in 3.4.110.
There are other 2 commits in drivers/gpu/drm/radeon betwwen 3.4.108 and 3.4.109, and "drm/radeon: fix VM_CONTEXT*_PAGE_TABLE_END_ADDR handling" has been partially reverted in mainline kernel, so I'll fix this too.
> Steven, you look to be using i915 graphics instead of radeon, so it seems > unlikely to me that we're hitting the same problem. Here's my oops for > comparison though: > ... > [<ffffffff810d4b93>] ? do_select+0x333/0x5f0 > [<ffffffffa03d90b2>] ? r600_cs_packet_parse+0x42/0x140 [radeon] > [<ffffffff810d4500>] ? __pollwait+0x110/0x110 > Oct 3 23:24:38 lancer last message repeated 7 times > [<ffffffff810ba216>] ? kmem_cache_free+0x86/0x90 > [<ffffffff81038d92>] ? __dequeue_signal+0x102/0x190 > [<ffffffff810d505c>] ? core_sys_select+0x20c/0x380 > [<ffffffff8103b608>] ? set_current_blocked+0x38/0x60 > [<ffffffff8103b6ec>] ? block_sigmask+0x3c/0x50 > [<ffffffff81001c84>] ? do_signal+0x1d4/0x620 > [<ffffffff8105b1ad>] ? ktime_get_ts+0x6d/0xe0 > [<ffffffff810d5212>] ? sys_select+0x42/0x110 > [<ffffffff81288982>] ? system_call_fastpath+0x16/0x1b
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