linux-kernel - Re: [Xen-devel] [PATCH 2/5] xen/x86-64: clean up warnings aboutIST-usingtraps

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: <4A046C3F.76EA.0078.0@novell.com>
Date:	Fri, 08 May 2009 16:30:39 +0100
From:	"Jan Beulich" <jbeulich@...ell.com>
To:	"Jeremy Fitzhardinge" <jeremy@...p.org>
Cc:	"Ingo Molnar" <mingo@...e.hu>,
	"the arch/x86 maintainers" <x86@...nel.org>,
	"Linus Torvalds" <torvalds@...ux-foundation.org>,
	"Xen-devel" <xen-devel@...ts.xensource.com>,
	"Linux Kernel Mailing List" <linux-kernel@...r.kernel.org>
Subject: Re: [Xen-devel] [PATCH 2/5] xen/x86-64: clean up warnings	
	 aboutIST-usingtraps

>>> Jeremy Fitzhardinge <jeremy@...p.org> 08.05.09 17:23 >>>
>Jan Beulich wrote:
>>> else if (addr == (unsigned long)int3)
>>> 		addr = (unsigned long)xen_int3;
>>> -	else
>>> -		WARN_ON(val->ist != 0);
>>> +	else if (addr == (unsigned long)double_fault ||
>>> +		 addr == (unsigned long)stack_segment) {
>>>     
>>
>> I don't think you want to exclude handling stack faults: Ordinary memory
>> references using rsp or rbp as the base register will cause these instead
>> of general protection faults when the resulting effective address is non-
>> canonical.
>>   
>
>So even usermode memory accesses?  Ew.

Yes, just try it out - you'll observe them generate SIGBUS instead of SIGSEGV.

Jan

--
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/