linux-kernel - RE: [PATCH] cxl/mbox: Fix CEL logic for poison and security commands

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]

Message-ID: <6501fcc4e2c9_31df4629421@iweiny-mobl.notmuch>
Date:   Wed, 13 Sep 2023 11:17:40 -0700
From:   Ira Weiny <ira.weiny@...el.com>
To:     Dan Williams <dan.j.williams@...el.com>,
        Ira Weiny <ira.weiny@...el.com>,
        Davidlohr Bueso <dave@...olabs.net>,
        Jonathan Cameron <jonathan.cameron@...wei.com>,
        Dave Jiang <dave.jiang@...el.com>,
        "Alison Schofield" <alison.schofield@...el.com>,
        Vishal Verma <vishal.l.verma@...el.com>
CC:     <linux-cxl@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        Ira Weiny <ira.weiny@...el.com>
Subject: RE: [PATCH] cxl/mbox: Fix CEL logic for poison and security commands

Dan Williams wrote:
> Ira Weiny wrote:
> > The following debug output was observed while testing CXL
> > 
> > cxl_core:cxl_walk_cel:721: cxl_mock_mem cxl_mem.0: Opcode 0x4300 unsupported by driver
> > 
> > opcode 0x4300 (Get Poison) is supported by the driver and the mock
> > device supports it.  The logic should be checking that the opcode is
> > both not poison and not security.
> > 
> > Fix the logic to allow poison and security commands.
> > 
> > Fixes: ad64f5952ce3 ("cxl/memdev: Only show sanitize sysfs files when supported")
> > Cc: Davidlohr Bueso <dave@...olabs.net>
> > Signed-off-by: Ira Weiny <ira.weiny@...el.com>
> > ---
> >  drivers/cxl/core/mbox.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> > index ca60bb8114f2..b315bdab9197 100644
> > --- a/drivers/cxl/core/mbox.c
> > +++ b/drivers/cxl/core/mbox.c
> > @@ -716,8 +716,8 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
> >  		u16 opcode = le16_to_cpu(cel_entry[i].opcode);
> >  		struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
> >  
> > -		if (!cmd && (!cxl_is_poison_command(opcode) ||
> > -			     !cxl_is_security_command(opcode))) {
> > +		if (!cmd && !cxl_is_poison_command(opcode) &&
> > +		    !cxl_is_security_command(opcode)) {
> 
> Given that this is going to be a recurring pattern to add optional
> command support, I am not a fan of continuing to expand this boolean
> algebra eye exam.
> 
> How about the following to only do the validation check and enabling in
> one place:

I like it.

Reviewed-by: Ira Weiny <ira.weiny@...el.com>

> 
> 
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index ca60bb8114f2..4df4f614f490 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -715,24 +715,25 @@ static void cxl_walk_cel(struct cxl_memdev_state *mds, size_t size, u8 *cel)
>  	for (i = 0; i < cel_entries; i++) {
>  		u16 opcode = le16_to_cpu(cel_entry[i].opcode);
>  		struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
> +		int enabled = 0;
>  
> -		if (!cmd && (!cxl_is_poison_command(opcode) ||
> -			     !cxl_is_security_command(opcode))) {
> -			dev_dbg(dev,
> -				"Opcode 0x%04x unsupported by driver\n", opcode);
> -			continue;
> -		}
> -
> -		if (cmd)
> +		if (cmd) {
>  			set_bit(cmd->info.id, mds->enabled_cmds);
> +			enabled++;
> +		}
>  
> -		if (cxl_is_poison_command(opcode))
> +		if (cxl_is_poison_command(opcode)) {
>  			cxl_set_poison_cmd_enabled(&mds->poison, opcode);
> +			enabled++;
> +		}
>  
> -		if (cxl_is_security_command(opcode))
> +		if (cxl_is_security_command(opcode)) {
>  			cxl_set_security_cmd_enabled(&mds->security, opcode);
> +			enabled++;
> +		}
>  
> -		dev_dbg(dev, "Opcode 0x%04x enabled\n", opcode);
> +		dev_dbg(dev, "Opcode 0x%04x %s\n", opcode,
> +			enabled ? "enabled" : "unsupported by driver");
>  	}
>  }
>