linux-kernel - Re: [RFC][PATCH 5/14] Introduce union stack

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:	Mon, 14 May 2007 22:51:13 +0200 (MEST)
From:	Jan Engelhardt <jengelh@...ux01.gwdg.de>
To:	Badari Pulavarty <pbadari@...ibm.com>
cc:	bharata@...ux.vnet.ibm.com, lkml <linux-kernel@...r.kernel.org>,
	linux-fsdevel <linux-fsdevel@...r.kernel.org>,
	Jan Blunck <j.blunck@...harburg.de>
Subject: Re: [RFC][PATCH  5/14] Introduce union stack


On May 14 2007 13:23, Badari Pulavarty wrote:
>> +static inline void union_lock_fs(struct fs_struct *fs)
>> +{
>> +	int locked;
>> +
>> +	while (fs) {
>> +		locked = union_trylock(fs->root);
>> +		if (!locked)
>> +			goto loop1;
>> +		locked = union_trylock(fs->altroot);
>> +		if (!locked)
>> +			goto loop2;
>> +		locked = union_trylock(fs->pwd);
>> +		if (!locked)
>> +			goto loop3;
>> +		break;
                ^^^^^^
>> +	loop3:
>> +		union_unlock(fs->altroot);
>> +	loop2:
>> +		union_unlock(fs->root);
>> +	loop1:
>> +		read_unlock(&fs->lock);
>> +		UM_DEBUG_LOCK("Failed to get all semaphores in fs_struct!\n");
>> +		cpu_relax();
>> +		read_lock(&fs->lock);
>> +		continue;
>
>Nit.. why "continue" ?

There's your break. Oh right, the continue is superfluous.

At the risk of using yet another goto, the conditional jump
could be turned into an inconditional one, since 'fs' will
remain valid. (Compiler smart enough to figure out?)

>> +	while (fs) {
	loop0:
>> +		locked = union_trylock(fs->root);
>> +		if (!locked)
>> +			goto loop1;
>> +		locked = union_trylock(fs->altroot);
>> +		if (!locked)
>> +			goto loop2;
>> +		locked = union_trylock(fs->pwd);
>> +		if (!locked)
>> +			goto loop3;
>> +		break;
>> +	loop3:
>> +		union_unlock(fs->altroot);
>> +	loop2:
>> +		union_unlock(fs->root);
>> +	loop1:
>> +		read_unlock(&fs->lock);
>> +		UM_DEBUG_LOCK("Failed to get all semaphores in fs_struct!\n");
>> +		cpu_relax();
>> +		read_lock(&fs->lock);
		/* continue */
		goto loop0;
	}


	Jan
-- 
-
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/