linux-kernel - arch_align_stack() seems useless

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-next>] [day] [month] [year] [list]

Message-ID: <46D2DADF.8060505@gmail.com>
Date:	Mon, 27 Aug 2007 16:08:31 +0200
From:	Franck Bui-Huu <vagabon.xyz@...il.com>
To:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: arch_align_stack() seems useless

Hello folks,

I recently pick up the implementation of arch_align_stack() from x86
architectures to make it available for mips.

But now I just realised that this function seems useless because of
the way it's used.

Currently, this function seems to be only used to randomize the stack
pointer inside a page during an execve() syscall. Only i386, x86_64
and recently mips do that. Here is the code taken from exec.c which
calls it:

	int setup_arg_pages(struct linux_binprm *bprm,
			    unsigned long stack_top,
			    int executable_stack)
	{
		[...]

		stack_top = arch_align_stack(stack_top);
		stack_top = PAGE_ALIGN(stack_top);

		[...]
	}

Since PAGE_ALIGN() is called right after arch_align_stack(), it seems
to me that the call to the latter function is useless...

Am I missing something ?

thanks

		Franck
-
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/