linux-kernel - Re: [PATCH] Common compat_sys

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:	Sun, 7 Jan 2007 08:18:17 -0700
From:	Matthew Wilcox <matthew@....cx>
To:	Christoph Hellwig <hch@...radead.org>,
	Kyle McMartin <kyle@...isc-linux.org>, akpm@...l.org,
	linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
	parisc-linux@...ts.parisc-linux.org
Subject: Re: [PATCH] Common compat_sys_sysinfo

On Sun, Jan 07, 2007 at 03:13:19PM +0000, Christoph Hellwig wrote:
> and last but not least we probably want a unified mechanisms to deal
> with the 64bit arguments that are broken up into two 32bit ones (not just
> for emulation but also for 32it BE architectures)

It's not BE that is the problem -- drepper thought of that.

What he fundamentally missed was the calling convention where 64-bit
arguments have to be 64-bit aligned, even when they're passed through
registers.  So:

int foo(int, long long);

takes its arguments in arg0, arg2 and arg3, but glibc passes the syscall
arguments in arg0, arg1 and arg2.

I think the Right Way to fix this is for some gcc hacker to implement an
__attribute__((packed_args)) that changes the calling convention for
that function, then we can define asmlinkage to use that on mips and
parisc.

Any budding gcc hackers out there?  ;-)
-
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/