linux-kernel - Re: [PATCH v1 1/1] Documentation: ACPI: Fix parent device references

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAJZ5v0inCyNEJW-B0zppJv74t07paX3aG-OX=x20sqY3A3A26A@mail.gmail.com>
Date: Fri, 11 Jul 2025 11:17:07 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org, 
	"Rafael J. Wysocki" <rafael@...nel.org>, Len Brown <lenb@...nel.org>, 
	Yevhen Kondrashyn <e.kondrashyn@...il.com>, stable@...r.kernel.org
Subject: Re: [PATCH v1 1/1] Documentation: ACPI: Fix parent device references

On Thu, Jul 10, 2025 at 7:03 PM Andy Shevchenko
<andriy.shevchenko@...ux.intel.com> wrote:
>
> The _CRS resources in many cases want to have ResourceSource field
> to be a type of ACPI String. This means that to compile properly
> we need to enclosure the name path into double quotes. This will
> in practice defer the interpretation to a run-time stage, However,
> this may be interpreted differently on different OSes and ACPI
> interpreter implementations. In particular ACPICA might not correctly
> recognize the leading '^' (caret) character and will not resolve
> the relative name path properly. On top of that, this piece may be
> used in SSDTs which are loaded after the DSDT and on itself may also
> not resolve relative name paths outside of their own scopes.
> With this all said, fix documentation to use fully-qualified name
> paths always to avoid any misinterpretations, which is proven to
> work.
>
> Fixes: 8eb5c87a92c0 ("i2c: add ACPI support for I2C mux ports")
> Reported-by: Yevhen Kondrashyn <e.kondrashyn@...il.com>
> Cc: stable@...r.kernel.org
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> ---
>
> Rafael, I prefer, if no objections, to push this as v6.16-rc6 material since
> the reported issue was detected on old (v5.10.y) and still LTS kernel. Would be
> nice for people to not trap to it in older kernels.
>
>  Documentation/firmware-guide/acpi/i2c-muxes.rst | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/firmware-guide/acpi/i2c-muxes.rst b/Documentation/firmware-guide/acpi/i2c-muxes.rst
> index 3a8997ccd7c4..f366539acd79 100644
> --- a/Documentation/firmware-guide/acpi/i2c-muxes.rst
> +++ b/Documentation/firmware-guide/acpi/i2c-muxes.rst
> @@ -14,7 +14,7 @@ Consider this topology::
>      |      |   | 0x70 |--CH01--> i2c client B (0x50)
>      +------+   +------+
>
> -which corresponds to the following ASL::
> +which corresponds to the following ASL (in the scope of \_SB)::
>
>      Device (SMB1)
>      {
> @@ -24,7 +24,7 @@ which corresponds to the following ASL::
>              Name (_HID, ...)
>              Name (_CRS, ResourceTemplate () {
>                  I2cSerialBus (0x70, ControllerInitiated, I2C_SPEED,
> -                            AddressingMode7Bit, "^SMB1", 0x00,
> +                            AddressingMode7Bit, "\\_SB.SMB1", 0x00,
>                              ResourceConsumer,,)
>              }
>
> @@ -37,7 +37,7 @@ which corresponds to the following ASL::
>                      Name (_HID, ...)
>                      Name (_CRS, ResourceTemplate () {
>                          I2cSerialBus (0x50, ControllerInitiated, I2C_SPEED,
> -                                    AddressingMode7Bit, "^CH00", 0x00,
> +                                    AddressingMode7Bit, "\\_SB.SMB1.CH00", 0x00,
>                                      ResourceConsumer,,)
>                      }
>                  }
> @@ -52,7 +52,7 @@ which corresponds to the following ASL::
>                      Name (_HID, ...)
>                      Name (_CRS, ResourceTemplate () {
>                          I2cSerialBus (0x50, ControllerInitiated, I2C_SPEED,
> -                                    AddressingMode7Bit, "^CH01", 0x00,
> +                                    AddressingMode7Bit, "\\_SB.SMB1.CH01", 0x00,
>                                      ResourceConsumer,,)
>                      }
>                  }
> --

Applied as 6.17 material, thanks!