linux-kernel - Re: [PATCH v3 2/5] ocxl: Clean up printf formats

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: <3e62601417f959c60d7f0c0311afb1d8484a0d1c.camel@perches.com>
Date:   Wed, 20 Mar 2019 10:24:41 -0700
From:   Joe Perches <joe@...ches.com>
To:     Alastair D'Silva <alastair@....ibm.com>, alastair@...ilva.org
Cc:     Frederic Barrat <fbarrat@...ux.ibm.com>,
        Andrew Donnellan <andrew.donnellan@....ibm.com>,
        Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/5] ocxl: Clean up printf formats

On Wed, 2019-03-20 at 16:34 +1100, Alastair D'Silva wrote:
> From: Alastair D'Silva <alastair@...ilva.org>
> 
> Use %# instead of using a literal '0x'

I do not suggest this as reasonable.

There are 10's of thousands of uses of 0x%x in the kernel
and converting them to save a byte seems unnecessary.

$ git grep -P '0x%[\*\d\.]*[xX]' | wc -l
26120

And the %#x style is by far the lesser used form

$ git grep -P '%#[\*\d\.]*[xX]' | wc -l
2726

Also, the sized form of %#[size]x is frequently misused
where the size does not account for the initial 0x output.

> diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
[]
> @@ -178,9 +178,9 @@ static int read_dvsec_vendor(struct pci_dev *dev)
>  	pci_read_config_dword(dev, pos + OCXL_DVSEC_VENDOR_DLX_VERS, &dlx);
>  
>  	dev_dbg(&dev->dev, "Vendor specific DVSEC:\n");
> -	dev_dbg(&dev->dev, "  CFG version = 0x%x\n", cfg);
> -	dev_dbg(&dev->dev, "  TLX version = 0x%x\n", tlx);
> -	dev_dbg(&dev->dev, "  DLX version = 0x%x\n", dlx);
> +	dev_dbg(&dev->dev, "  CFG version = %#x\n", cfg);
> +	dev_dbg(&dev->dev, "  TLX version = %#x\n", tlx);
> +	dev_dbg(&dev->dev, "  DLX version = %#x\n", dlx);

etc...