From: Dennis Zhou <dennis@kernel.org>
To: Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>
Cc: Tejun Heo <tj@kernel.org>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: kasan: paging percpu + kasan causes a double fault
Date: Mon, 8 Jul 2019 11:05:32 -0400 [thread overview]
Message-ID: <20190708150532.GB17098@dennisz-mbp> (raw)
Hi Andrey, Alexander, and Dmitry,
It was reported to me that when percpu is ran with param
percpu_alloc=page or the embed allocation scheme fails and falls back to
page that a double fault occurs.
I don't know much about how kasan works, but a difference between the
two is that we manually reserve vm area via vm_area_register_early().
I guessed it had something to do with the stack canary or the irq_stack,
and manually mapped the shadow vm area with kasan_add_zero_shadow(), but
that didn't seem to do the trick.
RIP resolves to the fixed_percpu_data declaration.
Double fault below:
[ 0.000000] PANIC: double fault, error_code: 0x0
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0-rc7-00007-ge0afe6d4d12c-dirty #299
[ 0.000000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
[ 0.000000] RIP: 0010:no_context+0x38/0x4b0
[ 0.000000] Code: df 41 57 41 56 4c 8d bf 88 00 00 00 41 55 49 89 d5 41 54 49 89 f4 55 48 89 fd 4c8
[ 0.000000] RSP: 0000:ffffc8ffffffff28 EFLAGS: 00010096
[ 0.000000] RAX: dffffc0000000000 RBX: ffffc8ffffffff50 RCX: 000000000000000b
[ 0.000000] RDX: fffff52000000030 RSI: 0000000000000003 RDI: ffffc90000000130
[ 0.000000] RBP: ffffc900000000a8 R08: 0000000000000001 R09: 0000000000000000
[ 0.000000] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003
[ 0.000000] R13: fffff52000000030 R14: 0000000000000000 R15: ffffc90000000130
[ 0.000000] FS: 0000000000000000(0000) GS:ffffc90000000000(0000) knlGS:0000000000000000
[ 0.000000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.000000] CR2: ffffc8ffffffff18 CR3: 0000000002e0d001 CR4: 00000000000606b0
[ 0.000000] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 0.000000] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 0.000000] Call Trace:
[ 0.000000] Kernel panic - not syncing: Machine halted.
[ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0-rc7-00007-ge0afe6d4d12c-dirty #299
[ 0.000000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
[ 0.000000] Call Trace:
[ 0.000000] <#DF>
[ 0.000000] dump_stack+0x5b/0x90
[ 0.000000] panic+0x17e/0x36e
[ 0.000000] ? __warn_printk+0xdb/0xdb
[ 0.000000] ? spurious_kernel_fault_check+0x1a/0x60
[ 0.000000] df_debug+0x2e/0x39
[ 0.000000] do_double_fault+0x89/0xb0
[ 0.000000] double_fault+0x1e/0x30
[ 0.000000] RIP: 0010:no_context+0x38/0x4b0
[ 0.000000] Code: df 41 57 41 56 4c 8d bf 88 00 00 00 41 55 49 89 d5 41 54 49 89 f4 55 48 89 fd 4c8
[ 0.000000] RSP: 0000:ffffc8ffffffff28 EFLAGS: 00010096
[ 0.000000] RAX: dffffc0000000000 RBX: ffffc8ffffffff50 RCX: 000000000000000b
[ 0.000000] RDX: fffff52000000030 RSI: 0000000000000003 RDI: ffffc90000000130
[ 0.000000] RBP: ffffc900000000a8 R08: 0000000000000001 R09: 0000000000000000
[ 0.000000] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003
[ 0.000000] R13: fffff52000000030 R14: 0000000000000000 R15: ffffc90000000130
Thanks,
Dennis
next reply other threads:[~2019-07-08 15:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-08 15:05 Dennis Zhou [this message]
2019-07-18 15:51 ` kasan: paging percpu + kasan causes a double fault Dmitry Vyukov
2019-07-18 16:20 ` Andrey Ryabinin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190708150532.GB17098@dennisz-mbp \
--to=dennis@kernel.org \
--cc=aryabinin@virtuozzo.com \
--cc=dvyukov@google.com \
--cc=glider@google.com \
--cc=kasan-dev@googlegroups.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=tj@kernel.org \
--cc=wangkefeng.wang@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).