linux-kernel - Re: [PATCH] x86: pass in pt_regs pointer for syscalls that need it (take 2)

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: <4993483F.8020809@zytor.com>
Date:	Wed, 11 Feb 2009 13:50:55 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Brian Gerst <brgerst@...il.com>
CC:	Tejun Heo <tj@...nel.org>, Ingo Molnar <mingo@...e.hu>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] x86: pass in pt_regs pointer for syscalls that need it
 (take 2)

Looks much better!

Brian Gerst wrote:
>  
>  #ifdef CONFIG_X86_32
> -/*
> - * Note: do not pass in pt_regs directly as with tail-call optimization
> - * GCC will incorrectly stomp on the caller's frame and corrupt user-space
> - * register state:
> - */
> -asmlinkage int sys_rt_sigreturn(unsigned long __unused)
> +int sys_rt_sigreturn(struct pt_regs *regs)
>  {
> -	struct pt_regs *regs = (struct pt_regs *)&__unused;
> -
>  	return do_rt_sigreturn(regs);
>  }
>  #else /* !CONFIG_X86_32 */

I observe with this sys_rt_sigreturn() is identical for both 32 and 64 
bits (since int == long for 32 bits.)  Furthermore, *both* are now no-op 
stubs around do_rt_sigreturn, so we can simply remove both stubs and 
change do_rt_sigreturn into sys_rt_sigreturn.

	-hpa
--
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/