linux-efi.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Hans de Goede <hdegoede@redhat.com>
To: Ard Biesheuvel <ardb@kernel.org>, linux-efi@vger.kernel.org
Cc: Matthew Garrett <matthewgarrett@google.com>,
	Ingo Molnar <mingo@kernel.org>, Andy Lutomirski <luto@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Arvind Sankar <nivedita@alum.mit.edu>
Subject: Re: [PATCH v2 00/21] efi/x86: confine type unsafe casting to mixed mode
Date: Thu, 19 Dec 2019 12:12:19 +0100	[thread overview]
Message-ID: <34f13f7f-a79c-16be-638a-c9267b740bce@redhat.com> (raw)
In-Reply-To: <20191218170139.9468-1-ardb@kernel.org>

Hi,

On 18-12-2019 18:01, Ard Biesheuvel wrote:
> Currently, we support mixed mode (64-bit Linux running on 32-bit firmware)
> by explicitly reasoning about pointer sizes for every call into the
> firmware: on x86, there are 32-bit and 64-bit versions of each protocol
> interface, and each call gets routed via one of the two, depending on the
> native size of the firmware.
> 
> There is a lot of casting and pointer mangling involved in this, and as
> a result, we end up with much less coverage in terms of type checking by
> the compiler, due to the indirection via an anonymous, variadic thunking
> routine.
> 
> This peculiarity of x86 is also leaking into generic EFI code, which is
> shared with ia64, arm64, ARM and likely RiscV in the future. So let's
> try to clean this up a bit.
> 
> The approach taken by this series is to replace the 32/64 bit distinction
> with a distinction between native calls and mixed mode calls, where the
> former can be either 32 or 64 bit [depending on the platform] and use
> the ordinary native protocol definitions, while mixed mode calls retain
> the existing casting/thunking approach based on the 32-bit protocol
> definitions.
> 
> Given that GCC now supports emitting function calls using the MS calling
> convention, we can get rid of all the wrapping and casting, and emit the
> indirect calls directly.
> 
> Changes since v1:
> - Substantially more cleanup work to simplify and hide the mixed mode handling
>    in generic EFI code.
> - Get rid of all the pointless passing around of sys_table_arg
> - Incorporate an updated version of Matthew's PCI DMA disable patch using EFI
>    events to defer poking the busmaster bits until after all the ordinary
>    ExitBootServices() callbacks have executed.
> 
> Code can be found here
> https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/log/?h=efistub-x86-cleanup-v2
> 
> Cc: Hans de Goede <hdegoede@redhat.com>
> Cc: Matthew Garrett <matthewgarrett@google.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Arvind Sankar <nivedita@alum.mit.edu>

I've merged ardb/efistub-x86-cleanup-v3 into my local tree for testing I will let
you know if I see any unexpected side-effects. I've set CONFIG_EFI_DISABLE_PCI_DMA=n
for now.

I did notice one small cosmetic issue with the last patch:

 > diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
 > index bcc378c19ebe..da2f5fc862aa 100644
 > --- a/drivers/firmware/efi/Kconfig
 > +++ b/drivers/firmware/efi/Kconfig
 > @@ -215,6 +215,28 @@ config EFI_RCI2_TABLE
 >
 >   	  Say Y here for Dell EMC PowerEdge systems.
 >
 > +config EFI_DISABLE_PCI_DMA
 > +       bool "Clear Busmaster bit on PCI bridges during ExitBootServices()"
 > +       help

The bool and help here seem to be indented by 7 spaces rather then by a tab.

Regards,

Hans



  parent reply	other threads:[~2019-12-19 11:12 UTC|newest]

Thread overview: 87+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-18 17:01 [PATCH v2 00/21] efi/x86: confine type unsafe casting to mixed mode Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 01/21] efi/libstub: remove unused __efi_call_early() macro Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 02/21] efi/x86: rename efi_is_native() to efi_is_mixed() Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 03/21] efi/libstub: use a helper to iterate over a EFI handle array Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 04/21] efi/libstub: extend native protocol definitions with mixed_mode aliases Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 05/21] efi/libstub: distinguish between native/mixed not 32/64 bit Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 06/21] efi/libstub/x86: use mixed mode helpers to populate efi_config Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 07/21] efi/libstub: drop explicit 32/64-bit protocol definitions Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 08/21] efi/libstub: use stricter typing for firmware function pointers Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 09/21] efi/libstub: annotate firmware routines as __efiapi Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 10/21] efi/libstub/x86: avoid thunking for native firmware calls Ard Biesheuvel
2019-12-21 21:22   ` Hans de Goede
2019-12-22 12:02     ` Ard Biesheuvel
2019-12-22 12:37       ` Ard Biesheuvel
2019-12-22 12:46       ` Andy Lutomirski
2019-12-22 15:29         ` Ard Biesheuvel
2019-12-22 21:12           ` Arvind Sankar
2019-12-22 21:25             ` Ard Biesheuvel
2019-12-23 11:49       ` Hans de Goede
2019-12-23 12:00         ` Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 11/21] efi/libstub: get rid of 'sys_table_arg' macro parameter Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 12/21] efi/libstub: unify the efi_char16_printk implementations Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 13/21] efi/libstub/x86: drop __efi_early() export of efi_config struct Ard Biesheuvel
2019-12-24 19:34   ` Hans de Goede
2019-12-25 14:42     ` Ard Biesheuvel
2019-12-27 22:44       ` Hans de Goede
2019-12-27 22:51         ` Ard Biesheuvel
2019-12-31 23:04   ` Arvind Sankar
2020-01-01 18:13     ` Ard Biesheuvel
2020-01-01 19:08       ` Arvind Sankar
2020-01-02  7:33         ` Ard Biesheuvel
2020-01-02 14:06           ` Arvind Sankar
2020-01-02 15:20             ` Ard Biesheuvel
2020-01-02 15:51               ` Arvind Sankar
2020-01-02 15:58                 ` Ard Biesheuvel
2020-01-02 16:28                   ` Ard Biesheuvel
2020-01-02 16:59                     ` Ard Biesheuvel
2020-01-02 17:26                       ` Arvind Sankar
2020-01-02 17:30                         ` Ard Biesheuvel
2020-01-02 17:41                           ` Arvind Sankar
2020-01-02 17:48                             ` Ard Biesheuvel
2020-01-02 18:10                               ` Arvind Sankar
2020-01-02 18:38                                 ` Ard Biesheuvel
2020-01-03 14:16                                   ` Arvind Sankar
2020-01-03 14:23                                     ` Ard Biesheuvel
2020-01-02 18:38                               ` Arvind Sankar
2020-01-02 16:59                     ` Arvind Sankar
2020-01-02 17:03                       ` Ard Biesheuvel
2020-01-02 17:21                         ` Arvind Sankar
2019-12-18 17:01 ` [PATCH v2 14/21] efi/libstub: drop sys_table_arg from printk routines Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 15/21] efi/libstub: remove 'sys_table_arg' from all function prototypes Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 16/21] efi/libstub: drop protocol argument from efi_call_proto() macro Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 17/21] efi/libstub: drop 'table' argument from efi_table_attr() macro Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 18/21] efi/libstub: use 'func' not 'f' as macro parameter Ard Biesheuvel
2019-12-31 16:51   ` Arvind Sankar
2019-12-31 17:06     ` Ard Biesheuvel
2019-12-31 17:36       ` Arvind Sankar
2019-12-18 17:01 ` [PATCH v2 19/21] efi/libstub: tidy up types and names of global cmdline variables Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 20/21] efi/libstub: import type definitions for creating and signalling events Ard Biesheuvel
2019-12-18 17:01 ` [PATCH v2 21/21] efi: Allow disabling PCI busmastering on bridges during boot Ard Biesheuvel
2019-12-19  2:50   ` Andy Lutomirski
2019-12-19 13:17     ` Ard Biesheuvel
2019-12-19 20:04       ` Matthew Garrett
2019-12-19 20:04   ` Matthew Garrett
2019-12-20  7:06     ` Ard Biesheuvel
2019-12-20  7:17       ` Andy Lutomirski
2019-12-20  8:11         ` Ard Biesheuvel
2019-12-20 19:41           ` Arvind Sankar
2020-01-02 14:46             ` Laszlo Ersek
2020-01-02 15:40               ` Ard Biesheuvel
2019-12-20 20:43       ` Matthew Garrett
2019-12-21 16:44         ` Ard Biesheuvel
2019-12-21 21:24           ` Matthew Garrett
2019-12-21 22:54             ` Arvind Sankar
2019-12-23 14:02               ` Ard Biesheuvel
2019-12-23 15:46                 ` Arvind Sankar
2019-12-23 15:58                   ` Ard Biesheuvel
2019-12-23 16:12                     ` Arvind Sankar
2019-12-23 20:57                   ` Matthew Garrett
2020-02-06 14:30   ` Hans de Goede
2020-02-06 14:35     ` Ard Biesheuvel
2020-03-04 10:38       ` Hans de Goede
2020-03-04 18:26         ` Ard Biesheuvel
2020-03-04 18:49           ` Hans de Goede
2020-03-04 21:59             ` Ard Biesheuvel
2019-12-19 11:12 ` Hans de Goede [this message]
2019-12-19 13:22   ` [PATCH v2 00/21] efi/x86: confine type unsafe casting to mixed mode Ard Biesheuvel

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=34f13f7f-a79c-16be-638a-c9267b740bce@redhat.com \
    --to=hdegoede@redhat.com \
    --cc=ardb@kernel.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=matthewgarrett@google.com \
    --cc=mingo@kernel.org \
    --cc=nivedita@alum.mit.edu \
    --cc=tglx@linutronix.de \
    /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).