LKML Archive on lore.kernel.org
 help / Atom feed
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: "Prakhya, Sai Praneeth" <sai.praneeth.prakhya@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"x86@kernel.org" <x86@kernel.org>, "bp@alien8.de" <bp@alien8.de>,
	"marc.zyngier@arm.com" <marc.zyngier@arm.com>,
	"eric.snowberg@oracle.com" <eric.snowberg@oracle.com>,
	"hdegoede@redhat.com" <hdegoede@redhat.com>,
	"Hansen, Dave" <dave.hansen@intel.com>,
	"peterz@infradead.org" <peterz@infradead.org>,
	"hpa@zytor.com" <hpa@zytor.com>,
	"arend.vanspriel@broadcom.com" <arend.vanspriel@broadcom.com>,
	"julien.thierry@arm.com" <julien.thierry@arm.com>,
	"bhsharma@redhat.com" <bhsharma@redhat.com>,
	"jonathanh@nvidia.com" <jonathanh@nvidia.com>,
	"joe@perches.com" <joe@perches.com>,
	"matt@codeblueprint.co.uk" <matt@codeblueprint.co.uk>,
	"torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
	"natechancellor@gmail.com" <natechancellor@gmail.com>,
	"luto@kernel.org" <luto@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"sedat.dilek@gmail.com" <sedat.dilek@gmail.com>,
	"zhuyifei1999@gmail.com" <zhuyifei1999@gmail.com>,
	"linux-tip-commits@vger.kernel.org" 
	<linux-tip-commits@vger.kernel.org>
Subject: Re: [tip:efi/core] x86/efi: Unmap EFI boot services code/data regions from efi_pgd
Date: Mon, 17 Dec 2018 19:10:58 +0100
Message-ID: <CAKv+Gu_vTHFxpKRu_CxKP-GdNdgdFKr7fi87VkNur0sqGQNVDw@mail.gmail.com> (raw)
In-Reply-To: <FFF73D592F13FD46B8700F0A279B802F48604575@ORSMSX114.amr.corp.intel.com>

On Mon, 17 Dec 2018 at 19:06, Prakhya, Sai Praneeth
<sai.praneeth.prakhya@intel.com> wrote:
>
> > Commit-ID:  08cfb38f3ef49cfd1bba11a00401451606477d80
> > Gitweb:
> > https://git.kernel.org/tip/08cfb38f3ef49cfd1bba11a00401451606477d80
> > Author:     Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
> > AuthorDate: Thu, 29 Nov 2018 18:12:24 +0100
> > Committer:  Ingo Molnar <mingo@kernel.org>
> > CommitDate: Fri, 30 Nov 2018 09:10:30 +0100
> >
> > x86/efi: Unmap EFI boot services code/data regions from efi_pgd
> >
> > efi_free_boot_services(), as the name suggests, frees EFI boot services
> > code/data regions but forgets to unmap these regions from efi_pgd. This means
> > that any code that's running in efi_pgd address space (e.g:
> > any EFI runtime service) would still be able to access these regions but the
> > contents of these regions would have long been over written by someone else.
> > So, it's important to unmap these regions. Hence, introduce efi_unmap_pages()
> > to unmap these regions from efi_pgd.
> >
> > After unmapping EFI boot services code/data regions, any illegal access by
> > buggy firmware to these regions would result in page fault which will be handled
> > by EFI specific fault handler.
>
> Hi Thomas and Ingo,
>
> I recently noticed that the below commits [1] and [2] are broken when kernel command line
> argument "efi=old_map" is passed. Sorry! I missed to test this condition prior to sending
> these patches to mailing list. I am working on a fix and will send it to mailing list as
> soon as it's ready.
>

Could you elaborate on the problem please?

> Meanwhile, could you please drop these patches before sending pull request to Linus?
>
> [1] Commit 08cfb38f3ef4 ("x86/efi: Unmap EFI boot services code/data regions from efi_pgd")
> [2] Commit 7e0dabd3010d ("x86/mm/pageattr: Introduce helper function to unmap EFI boot services")
>

I'd like to understand what the issue is before we drop anything.

  reply index

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-29 17:12 [GIT PULL 00/11] EFI updates Ard Biesheuvel
2018-11-29 17:12 ` [PATCH 01/11] x86/efi: Allocate e820 buffer before calling efi_exit_boot_service Ard Biesheuvel
2018-11-30  7:29   ` Ingo Molnar
2018-11-30  8:26     ` Ard Biesheuvel
2018-11-30  8:36       ` Ingo Molnar
2018-11-30  9:55   ` [tip:efi/core] " tip-bot for Eric Snowberg
2018-11-29 17:12 ` [PATCH 02/11] efi/fdt: Indentation fix Ard Biesheuvel
2018-11-30  7:56   ` [PATCH] efi/fdt: More cleanups Ingo Molnar
2018-11-30  8:31     ` Ard Biesheuvel
2018-11-30  9:48       ` Ingo Molnar
2018-11-30  9:56   ` [tip:efi/core] efi/fdt: Indentation fix tip-bot for Julien Thierry
2018-11-29 17:12 ` [PATCH 03/11] efi/fdt: Simplify get_fdt flow Ard Biesheuvel
2018-11-30  9:57   ` [tip:efi/core] efi/fdt: Simplify the get_fdt() flow tip-bot for Julien Thierry
2018-11-29 17:12 ` [PATCH 04/11] x86/mm/pageattr: Introduce helper function to unmap EFI boot services Ard Biesheuvel
2018-11-30  9:58   ` [tip:efi/core] " tip-bot for Sai Praneeth Prakhya
2018-11-29 17:12 ` [PATCH 05/11] x86/efi: Unmap EFI boot services code/data regions from efi_pgd Ard Biesheuvel
2018-11-30  9:58   ` [tip:efi/core] " tip-bot for Sai Praneeth Prakhya
2018-12-17 18:06     ` Prakhya, Sai Praneeth
2018-12-17 18:10       ` Ard Biesheuvel [this message]
2018-12-17 18:42         ` Prakhya, Sai Praneeth
2018-12-17 19:35           ` Ard Biesheuvel
2018-12-17 19:48             ` Prakhya, Sai Praneeth
2018-12-21 17:02               ` Ard Biesheuvel
2018-12-21 17:13                 ` Borislav Petkov
2018-12-21 17:26                   ` Ard Biesheuvel
2018-12-21 19:29                     ` Borislav Petkov
2018-12-22 11:07                       ` Ard Biesheuvel
2019-01-07 15:57                         ` Matt Fleming
2018-12-21 17:52                 ` Prakhya, Sai Praneeth
2018-11-29 17:12 ` [PATCH 06/11] x86/efi: Move efi_<reserve/free>_boot_services() to arch/x86 Ard Biesheuvel
2018-11-30  9:59   ` [tip:efi/core] " tip-bot for Sai Praneeth Prakhya
2018-11-29 17:12 ` [PATCH 07/11] efi/libstub: Disable some warnings for x86{,_64} Ard Biesheuvel
2018-11-30  9:59   ` [tip:efi/core] " tip-bot for Nathan Chancellor
2018-11-29 17:12 ` [PATCH 08/11] firmware: efi: add NULL pointer checks in efivars api functions Ard Biesheuvel
2018-11-30  8:11   ` Ingo Molnar
2018-11-30  8:37     ` Ard Biesheuvel
2018-11-30  9:56   ` [tip:efi/core] firmware/efi: Add NULL pointer checks in efivars API functions tip-bot for Arend van Spriel
2018-11-29 17:12 ` [PATCH 09/11] efi: permit multiple entries in persistent memreserve data structure Ard Biesheuvel
2018-11-30 10:00   ` [tip:efi/core] efi: Permit " tip-bot for Ard Biesheuvel
2018-11-29 17:12 ` [PATCH 10/11] efi: reduce the amount of memblock reservations for persistent allocations Ard Biesheuvel
2018-11-30  8:38   ` Ingo Molnar
2018-11-30  8:39     ` Ard Biesheuvel
2018-11-30 10:00   ` [tip:efi/core] efi: Reduce " tip-bot for Ard Biesheuvel
2018-11-29 17:12 ` [PATCH 11/11] efi/x86: earlyprintk - Fix infinite loop on some screen widths Ard Biesheuvel
2018-11-30  8:05   ` Ingo Molnar
2018-11-30  8:32     ` Ard Biesheuvel
2018-11-30  9:55   ` [tip:efi/core] x86/earlyprintk/efi: " tip-bot for YiFei Zhu
2018-11-29 18:27 ` [GIT PULL 00/11] EFI updates Prakhya, Sai Praneeth
2018-11-30 12:01   ` Ard Biesheuvel
2018-11-30 18:01     ` Prakhya, Sai Praneeth

Reply instructions:

You may reply publically 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=CAKv+Gu_vTHFxpKRu_CxKP-GdNdgdFKr7fi87VkNur0sqGQNVDw@mail.gmail.com \
    --to=ard.biesheuvel@linaro.org \
    --cc=arend.vanspriel@broadcom.com \
    --cc=bhsharma@redhat.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@intel.com \
    --cc=eric.snowberg@oracle.com \
    --cc=hdegoede@redhat.com \
    --cc=hpa@zytor.com \
    --cc=joe@perches.com \
    --cc=jonathanh@nvidia.com \
    --cc=julien.thierry@arm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tip-commits@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=marc.zyngier@arm.com \
    --cc=matt@codeblueprint.co.uk \
    --cc=mingo@kernel.org \
    --cc=natechancellor@gmail.com \
    --cc=peterz@infradead.org \
    --cc=sai.praneeth.prakhya@intel.com \
    --cc=sedat.dilek@gmail.com \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=x86@kernel.org \
    --cc=zhuyifei1999@gmail.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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org linux-kernel@archiver.kernel.org
	public-inbox-index lkml


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox