From: Xing Zhengjun <zhengjun.xing@linux.intel.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
kernel test robot <oliver.sang@intel.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
Harish Sriram <harish@linux.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
lkp@lists.01.org, kernel test robot <lkp@intel.com>
Subject: Re: [LKP] Re: [mm/vunmap] e47110e905: WARNING:at_mm/vmalloc.c:#__vunmap
Date: Wed, 28 Apr 2021 16:32:28 +0800 [thread overview]
Message-ID: <4b0fd107-5509-3d2a-1151-335f9296f8e5@linux.intel.com> (raw)
In-Reply-To: <CAHk-=wg8iAG6bBB+zdoZvZx1XYmyAXrWL0gPs_eTrTt+tXN0Tw@mail.gmail.com>
Hi Linus,
On 4/24/2021 1:18 AM, Linus Torvalds wrote:
> On Thu, Apr 22, 2021 at 11:15 PM kernel test robot
> <oliver.sang@intel.com> wrote:
>>
>> commit: e47110e90584a22e9980510b00d0dfad3a83354e ("mm/vunmap: add cond_resched() in vunmap_pmd_range")
>
> Funky. That commit doesn't seem to have anything to do with the oops.
>
> The oops is odd too:
>
>> [ 198.731223] WARNING: CPU: 0 PID: 1948 at mm/vmalloc.c:2247 __vunmap (kbuild/src/consumer/mm/vmalloc.c:2247 (discriminator 1))
>
> That's the warning for an unaligned vunmap():
>
> 2247 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad
> address (%p)\n",
> 2248 addr))
> 2249 return;
>
>> [ 198.744933] Call Trace:
>> [ 198.745229] free_module (kbuild/src/consumer/kernel/module.c:2251)
>
> 2248 /* This may be empty, but that's OK */
> 2249 module_arch_freeing_init(mod);
> 2250 module_memfree(mod->init_layout.base);
We add debug code to print logs when mod->init_layout.base is NULL,
after more than 100 times test, we find that when mod->init_layout.base
is NULL, no align warning happened. From the descriptions of vfree, if
@addr is NULL, no operation is performed. So when the warning happened,
the mod->init_layout.base is not a NULL.
void vfree(const void *addr)
{
BUG_ON(in_nmi());
kmemleak_free(addr);
might_sleep_if(!in_interrupt());
if (!addr)
return;
__vfree(addr);
}
static void __vfree(const void *addr)
{
if (unlikely(in_interrupt()))
__vfree_deferred(addr);
else
__vunmap(addr, 1);
}
> 2251 kfree(mod->args);
>
> That's the "module_memfree()" - the return address points to the
> return point, which is the next line.
>
> And as far as I can tell, the only thing that assigns anything but
> NULL to that init_layout.base is
>
> ptr = module_alloc(mod->init_layout.size);
>
> which uses __vmalloc_node_range() for the allocation.
>
> So absolutely nothing in this report makes sense to me. I suspect it's
> some odd memory corruption.
>
> Oliver - how reliable is that bisection?
>
> Does anybody else see what might be up?
>
> Linus
> _______________________________________________
> LKP mailing list -- lkp@lists.01.org
> To unsubscribe send an email to lkp-leave@lists.01.org
>
--
Zhengjun Xing
prev parent reply other threads:[~2021-04-28 8:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-23 6:32 [mm/vunmap] e47110e905: WARNING:at_mm/vmalloc.c:#__vunmap kernel test robot
2021-04-23 17:18 ` Linus Torvalds
2021-04-25 1:48 ` Oliver Sang
2021-04-25 2:04 ` Linus Torvalds
2021-04-29 7:53 ` Oliver Sang
2021-04-29 17:31 ` Linus Torvalds
2021-05-03 14:43 ` Jessica Yu
2021-04-28 8:32 ` Xing Zhengjun [this message]
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=4b0fd107-5509-3d2a-1151-335f9296f8e5@linux.intel.com \
--to=zhengjun.xing@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.ibm.com \
--cc=harish@linux.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lkp@intel.com \
--cc=lkp@lists.01.org \
--cc=oliver.sang@intel.com \
--cc=torvalds@linux-foundation.org \
/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).