All of lore.kernel.org
 help / color / mirror / Atom feed
From: toshi.kani@hpe.com (Kani, Toshi)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/3] x86/mm: disable ioremap free page handling on x86-PAE
Date: Wed, 9 May 2018 15:47:19 +0000	[thread overview]
Message-ID: <1525880775.2693.558.camel@hpe.com> (raw)
In-Reply-To: <20180430175925.2657-4-toshi.kani@hpe.com>

On Mon, 2018-04-30 at 11:59 -0600, Toshi Kani wrote:
> ioremap() supports pmd mappings on x86-PAE.  However, kernel's pmd
> tables are not shared among processes on x86-PAE.  Therefore, any
> update to sync'd pmd entries need re-syncing.  Freeing a pte page
> also leads to a vmalloc fault and hits the BUG_ON in vmalloc_sync_one().
> 
> Disable free page handling on x86-PAE.  pud_free_pmd_page() and
> pmd_free_pte_page() simply return 0 if a given pud/pmd entry is present.
> This assures that ioremap() does not update sync'd pmd entries at the
> cost of falling back to pte mappings.
> 
> Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
> Reported-by: Joerg Roedel <joro@8bytes.org>

Hi Joerg,

Does it solve your problem?  Let me know if you have any issue with the
series. 

Thanks,
-Toshi

WARNING: multiple messages have this Message-ID (diff)
From: "Kani, Toshi" <toshi.kani@hpe.com>
To: "tglx@linutronix.de" <tglx@linutronix.de>,
	"hpa@zytor.com" <hpa@zytor.com>,
	"joro@8bytes.org" <joro@8bytes.org>,
	"Hocko, Michal" <MHocko@suse.com>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"mingo@redhat.com" <mingo@redhat.com>
Cc: "linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"cpandya@codeaurora.org" <cpandya@codeaurora.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"x86@kernel.org" <x86@kernel.org>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: [PATCH 3/3] x86/mm: disable ioremap free page handling on x86-PAE
Date: Wed, 9 May 2018 15:47:19 +0000	[thread overview]
Message-ID: <1525880775.2693.558.camel@hpe.com> (raw)
In-Reply-To: <20180430175925.2657-4-toshi.kani@hpe.com>

On Mon, 2018-04-30 at 11:59 -0600, Toshi Kani wrote:
> ioremap() supports pmd mappings on x86-PAE.  However, kernel's pmd
> tables are not shared among processes on x86-PAE.  Therefore, any
> update to sync'd pmd entries need re-syncing.  Freeing a pte page
> also leads to a vmalloc fault and hits the BUG_ON in vmalloc_sync_one().
> 
> Disable free page handling on x86-PAE.  pud_free_pmd_page() and
> pmd_free_pte_page() simply return 0 if a given pud/pmd entry is present.
> This assures that ioremap() does not update sync'd pmd entries at the
> cost of falling back to pte mappings.
> 
> Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
> Reported-by: Joerg Roedel <joro@8bytes.org>

Hi Joerg,

Does it solve your problem?  Let me know if you have any issue with the
series. 

Thanks,
-Toshi

  reply	other threads:[~2018-05-09 15:47 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-30 17:59 [PATCH 0/3] fix free pmd/pte page handlings on x86 Toshi Kani
2018-04-30 17:59 ` Toshi Kani
2018-04-30 17:59 ` [PATCH 1/3] ioremap: Update pgtable free interfaces with addr Toshi Kani
2018-04-30 17:59   ` Toshi Kani
2018-04-30 17:59 ` [PATCH 2/3] x86/mm: add TLB purge to free pmd/pte page interfaces Toshi Kani
2018-04-30 17:59   ` Toshi Kani
2018-05-15 14:05   ` Joerg Roedel
2018-05-15 14:05     ` Joerg Roedel
2018-05-15 16:34     ` Kani, Toshi
2018-05-15 16:34       ` Kani, Toshi
2018-04-30 17:59 ` [PATCH 3/3] x86/mm: disable ioremap free page handling on x86-PAE Toshi Kani
2018-04-30 17:59   ` Toshi Kani
2018-05-09 15:47   ` Kani, Toshi [this message]
2018-05-09 15:47     ` Kani, Toshi

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=1525880775.2693.558.camel@hpe.com \
    --to=toshi.kani@hpe.com \
    --cc=linux-arm-kernel@lists.infradead.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 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.