Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751525AbWAFQNY (ORCPT ); Fri, 6 Jan 2006 11:13:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751545AbWAFQNY (ORCPT ); Fri, 6 Jan 2006 11:13:24 -0500 Received: from liaag2aa.mx.compuserve.com ([149.174.40.154]:10375 "EHLO liaag2aa.mx.compuserve.com") by vger.kernel.org with ESMTP id S1751523AbWAFQNY (ORCPT ); Fri, 6 Jan 2006 11:13:24 -0500 Date: Fri, 6 Jan 2006 11:10:16 -0500 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: Re: ptrace denies access to EFLAGS_RF To: Stephane Eranian Cc: linux-kernel , Andi Kleen , discuss@x86-64.org Message-ID: <200601061112_MC3-1-B567-47BB@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2178 Lines: 64 In-Reply-To: <20060106140217.GD7676@frankl.hpl.hp.com> On Fri, 6 Jan 2006 at 06:02:17 -0800, Stephane Eranian wrote: > To my surprise, applying the same fix to the x86_64 does not > solve the problem on my Opteron box. I verified that the > offset (144) matches with what the kernel is expecting. > Somehow the RF is lost or not set in the proper location. > I cannot make forward progress once I reach the breakpoint. I sent this to Andi this morning. Does it work for you? Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> arch/x86_64/ia32/ptrace32.c | 9 ++++++--- arch/x86_64/kernel/ptrace.c | 9 ++++++--- 2 files changed, 12 insertions(+), 6 deletions(-) --- 2.6.15-64a.orig/arch/x86_64/ia32/ptrace32.c +++ 2.6.15-64a/arch/x86_64/ia32/ptrace32.c @@ -28,9 +28,12 @@ #include #include -/* determines which flags the user has access to. */ -/* 1 = access 0 = no access */ -#define FLAG_MASK 0x44dd5UL +/* + * Determines which flags the user has access to [1 = access, 0 = no access]. + * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9). + * Also masks reserved bits (31-22, 15, 5, 3, 1). + */ +#define FLAG_MASK 0x54dd5UL #define R32(l,q) \ case offsetof(struct user32, regs.l): stack[offsetof(struct pt_regs, q)/8] = val; break --- 2.6.15-64a.orig/arch/x86_64/kernel/ptrace.c +++ 2.6.15-64a/arch/x86_64/kernel/ptrace.c @@ -36,9 +36,12 @@ * in exit.c or in signal.c. */ -/* determines which flags the user has access to. */ -/* 1 = access 0 = no access */ -#define FLAG_MASK 0x44dd5UL +/* + * Determines which flags the user has access to [1 = access, 0 = no access]. + * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9). + * Also masks reserved bits (63-22, 15, 5, 3, 1). + */ +#define FLAG_MASK 0x54dd5UL /* set's the trap flag. */ #define TRAP_FLAG 0x100UL -- Chuck Currently reading: _Thud!_ by Terry Pratchett - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/