All of lore.kernel.org
 help / color / mirror / Atom feed
From: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: kexec@lists.infradead.org,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Jan Willeke <willeke@de.ibm.com>,
	Michael Holzheu <holzheu@linux.vnet.ibm.com>,
	"David S. Miller" <davem@davemloft.net>,
	Vivek Goyal <vgoyal@redhat.com>
Subject: Re: mmap for /proc/vmcore broken since 3.12-rc1
Date: Wed, 09 Oct 2013 19:14:55 +0900	[thread overview]
Message-ID: <52552C9F.2030404@jp.fujitsu.com> (raw)
In-Reply-To: <CACVxJT8S7kA92=80DWVmVJJvbnaQ6WkyvsiFq4wP37WHV=tfuA@mail.gmail.com>

Hello,

(2013/10/08 21:49), Alexey Dobriyan wrote:
> On Mon, Oct 7, 2013 at 5:42 AM, HATAYAMA Daisuke
> <d.hatayama@jp.fujitsu.com> wrote:
>
>> +static unsigned long
>> +get_unmapped_area_vmcore(struct file *filp, unsigned long addr,
>> +                        unsigned long len, unsigned long pgoff,
>> +                        unsigned long flags)
>> +{
>> +#ifdef CONFIG_MMU
>> +       return current->mm->get_unmapped_area(filp, addr, len, pgoff,
>> flags);
>> +#else
>> +       return -EIO;
>> +#endif
>> +}
>> +
>>   static const struct file_operations proc_vmcore_operations = {
>>          .read           = read_vmcore,
>>          .llseek         = default_llseek,
>>          .mmap           = mmap_vmcore,
>> +       .get_unmapped_area = get_unmapped_area_vmcore,
>
> I think current->mm->get_unmapped_area should be used by core proc code.

What do you actually suggest here? You mean moving this code in proc code?
I don't think you suggest so.

> ENOMEM bug looks unrelated though.
>

Next step I'll do is to look into vm_unmapped_region() that looks for
for a region fit to a given mmap request and returns its address.
In particular, I'll focus on when vm_unmapped_region() could return
kernel-space address.

-- 
Thanks.
HATAYAMA, Daisuke


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

WARNING: multiple messages have this Message-ID (diff)
From: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>,
	"David S. Miller" <davem@davemloft.net>,
	Vivek Goyal <vgoyal@redhat.com>, Jan Willeke <willeke@de.ibm.com>,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	kexec@lists.infradead.org
Subject: Re: mmap for /proc/vmcore broken since 3.12-rc1
Date: Wed, 09 Oct 2013 19:14:55 +0900	[thread overview]
Message-ID: <52552C9F.2030404@jp.fujitsu.com> (raw)
In-Reply-To: <CACVxJT8S7kA92=80DWVmVJJvbnaQ6WkyvsiFq4wP37WHV=tfuA@mail.gmail.com>

Hello,

(2013/10/08 21:49), Alexey Dobriyan wrote:
> On Mon, Oct 7, 2013 at 5:42 AM, HATAYAMA Daisuke
> <d.hatayama@jp.fujitsu.com> wrote:
>
>> +static unsigned long
>> +get_unmapped_area_vmcore(struct file *filp, unsigned long addr,
>> +                        unsigned long len, unsigned long pgoff,
>> +                        unsigned long flags)
>> +{
>> +#ifdef CONFIG_MMU
>> +       return current->mm->get_unmapped_area(filp, addr, len, pgoff,
>> flags);
>> +#else
>> +       return -EIO;
>> +#endif
>> +}
>> +
>>   static const struct file_operations proc_vmcore_operations = {
>>          .read           = read_vmcore,
>>          .llseek         = default_llseek,
>>          .mmap           = mmap_vmcore,
>> +       .get_unmapped_area = get_unmapped_area_vmcore,
>
> I think current->mm->get_unmapped_area should be used by core proc code.

What do you actually suggest here? You mean moving this code in proc code?
I don't think you suggest so.

> ENOMEM bug looks unrelated though.
>

Next step I'll do is to look into vm_unmapped_region() that looks for
for a region fit to a given mmap request and returns its address.
In particular, I'll focus on when vm_unmapped_region() could return
kernel-space address.

-- 
Thanks.
HATAYAMA, Daisuke


  reply	other threads:[~2013-10-09 10:15 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-02 12:03 mmap for /proc/vmcore broken since 3.12-rc1 Michael Holzheu
2013-10-02 12:03 ` Michael Holzheu
2013-10-03  6:12 ` HATAYAMA Daisuke
2013-10-03  6:12   ` HATAYAMA Daisuke
2013-10-07  2:42   ` HATAYAMA Daisuke
2013-10-07  2:42     ` HATAYAMA Daisuke
2013-10-08 12:49     ` Alexey Dobriyan
2013-10-08 12:49       ` Alexey Dobriyan
2013-10-09 10:14       ` HATAYAMA Daisuke [this message]
2013-10-09 10:14         ` HATAYAMA Daisuke
2013-10-12 20:32         ` Alexey Dobriyan
2013-10-12 20:32           ` Alexey Dobriyan
2013-10-14  4:52           ` HATAYAMA Daisuke
2013-10-14  4:52             ` HATAYAMA Daisuke

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=52552C9F.2030404@jp.fujitsu.com \
    --to=d.hatayama@jp.fujitsu.com \
    --cc=adobriyan@gmail.com \
    --cc=davem@davemloft.net \
    --cc=holzheu@linux.vnet.ibm.com \
    --cc=kexec@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=vgoyal@redhat.com \
    --cc=willeke@de.ibm.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.