linux-kernel - Re: [PATCH v3 3/5] platform/chrome: cros_ec_proto: Introduce cros_ec_cmd

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

Date: Tue, 11 Jun 2024 10:14:41 +0000
From: Tzung-Bi Shih <tzungbi@...nel.org>
To: Thomas Weißschuh <linux@...ssschuh.net>
Cc: Benson Leung <bleung@...omium.org>, Guenter Roeck <groeck@...omium.org>,
	Sebastian Reichel <sre@...nel.org>,
	"Rafael J. Wysocki" <rafael@...nel.org>,
	Len Brown <lenb@...nel.org>, Robert Moore <robert.moore@...el.com>,
	chrome-platform@...ts.linux.dev, linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org,
	Mario Limonciello <mario.limonciello@....com>,
	Dustin Howett <dustin@...ett.net>,
	Stephen Horvath <s.horvath@...look.com.au>,
	Rajas Paranjpe <paranjperajas@...il.com>,
	linux-acpi@...r.kernel.org, acpica-devel@...ts.linux.dev,
	Matt Hartley <matt.hartley@...il.com>
Subject: Re: [PATCH v3 3/5] platform/chrome: cros_ec_proto: Introduce
 cros_ec_cmd_versions()

On Tue, Jun 11, 2024 at 09:23:24AM +0200, Thomas Weißschuh wrote:
> On 2024-06-11 06:32:38+0000, Tzung-Bi Shih wrote:
> > On Mon, Jun 10, 2024 at 05:51:08PM +0200, Thomas Weißschuh wrote:
> > > If the command is not supported at all the EC returns
> > > -EINVAL/EC_RES_INVALID_PARAMS.
> > > 
> > > This error is translated into an empty version mask as that is easier to
> > > handle for callers and they don't need to know about the error details.
> > 
> > I'm not sure whether the behavior is what we want or not as existing
> > EC_CMD_GET_CMD_VERSIONS usages don't have it.
> 
> At least the caller of cros_ec_get_host_command_version_mask() expects
> it:
> 
> ret = cros_ec_get_host_command_version_mask(..., &ver_mask);
> if (ret < 0 || ver_mask == 0)
> ...
> 
> ver_mask == 0 will never happen as in that case -EINVAL would have been
> returned.
> 
> Others, like cros_ec_cec_get_write_cmd_version(), expect the current
> semantic of ver_mask != 0 but log spurious errors in case of -EINVAL.
> cros_pchg_cmd_ver_check(), works with both semantics, but currently also
> logs a spurious error message.
> 
> To me the new semantic looks more obvious and much easier to handle.
> For each command version a bit is set. no command versions -> no bits.

Ack.