linux-kernel - Re: coding for optimizations (Re: [PATCH 1/2] i386: mce cleanup part1: functional change)

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: <20071009183011.GE13205@amd.com>
Date:	Tue, 9 Oct 2007 20:30:11 +0200
From:	"Joerg Roedel" <joerg.roedel@....com>
To:	olecom@...wer.upol.cz
cc:	"LKML (Cc removed)" <linux-kernel@...r.kernel.org>
Subject: Re: coding for optimizations (Re: [PATCH 1/2] i386: mce cleanup
 part1: functional change)

On Tue, Oct 09, 2007 at 07:33:17PM +0200, olecom@...wer.upol.cz wrote:
> 	if (!mce_disabled) {
> 	if (!(c->x86_capability & (X86_FEATURE_MCA | X86_FEATURE_MCE)) {
> 		printk(KERN_INFO "CPU%i: No machine check support available\n",
>  			smp_processor_id());
> 		return;
> 	}
> 	/* function code */
> 	}

I have 2 problems with this way:

1) It is totally broken because c->x86_capability is not an integer but
   an *array* of integers. This is also the reason why test_bit() is used
   in cpu_has() and not plain logical operators.

2) It is still hard to read and breaks the kernel coding style.

But you are right with the redundant mca and mce variables. They are not
needed and I will inline the cpu_has() checks into the condition check.
I'll resubmit tomorrow.

-- 
           |           AMD Saxony Limited Liability Company & Co. KG
 Operating |         Wilschdorfer Landstr. 101, 01109 Dresden, Germany
 System    |                  Register Court Dresden: HRA 4896
 Research  |              General Partner authorized to represent:
 Center    |             AMD Saxony LLC (Wilmington, Delaware, US)
           | General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/