linux-kernel - Re: [patch 3/3] tracepoints: use __u64_aligned/U64

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: <20110121.160516.256850550.davem@davemloft.net>
Date:	Fri, 21 Jan 2011 16:05:16 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	mathieu.desnoyers@...icios.com
Cc:	linux-kernel@...r.kernel.org, rostedt@...dmis.org,
	fweisbec@...il.com, mingo@...e.hu, richm@...elvet.org.uk,
	ben@...adent.org.uk, sparclinux@...r.kernel.org
Subject: Re: [patch 3/3] tracepoints: use __u64_aligned/U64_ALIGN()

From: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
Date: Fri, 21 Jan 2011 15:36:33 -0500

> commit 7e066fb870fcd1025ec3ba7bbde5d541094f4ce1 added the aligned(32) type and
> variable attribute to the tracepoint structures to deal with gcc happily
> aligning statically defined structures on 32-byte multiples.
> 
> Working on issues within Ftrace, we came up with __64_aligned, which deals with
> this issue more elegantly by forcing an 8-byte alignment to both the type
> declaration and variable definition.
> 
> This therefore saves space, bringing down the size of struct tracepoint from 64
> bytes to 38 on 64-bit architectures.
> 
> Updating:
> - The type attribute (for iteration over the struct tracepoint array)
> - Added the variable attribute to the extern definition (needed to force gcc to
>   consider this alignment for the following definition)
> - The definition variable attribute (to force gcc to this specific alignment for
>   the static definitions)
> - The linker script (8-byte alignment can now replace the previous 32-byte
>   alignment for the custom tracepoint section)
> 
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>

Acked-by: David S. Miller <davem@...emloft.net>
--
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/