From: Denys Vlasenko <dvlasenk@redhat.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: linux-kernel@vger.kernel.org, Jim Keniston <jkenisto@us.ibm.com>,
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH 1/2] uprobes: add comment with insn opcodes, mnemonics and why we dont support them
Date: Tue, 06 May 2014 19:01:32 +0200 [thread overview]
Message-ID: <5369156C.4000602@redhat.com> (raw)
In-Reply-To: <20140505194100.GA26916@redhat.com>
On 05/05/2014 09:41 PM, Oleg Nesterov wrote:
> On 05/05, Denys Vlasenko wrote:
>>
>> + * Opcodes we'll probably never support:
>> + * 6c-6f - ins,outs. SEGVs if used in userspace
>> + * e4-e7 - in,out imm. SEGVs if used in userspace
>> + * ec-ef - in,out acc. SEGVs if used in userspace
>
> Well. I have no idea why they are nacked, but this is not the reason.
>
> SEGVs are fine. Plus we have ioperm().
Noted.
Oleg, can you clear for me the following -
If the probed instruction triggers an "illegal insn" or "privileged insn"
CPU exception - are we completely fine?
Or there are some problems? how bad are they?
Slightly wrong signal stack? Wrong EFLAGs on stack?
Wrong address of failing insn?
next prev parent reply other threads:[~2014-05-06 17:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-05 18:24 [PATCH 1/2] uprobes: add comment with insn opcodes, mnemonics and why we dont support them Denys Vlasenko
2014-05-05 18:24 ` [PATCH 2/2] uprobes: fix 1-byte opcode tables Denys Vlasenko
2014-05-05 19:41 ` [PATCH 1/2] uprobes: add comment with insn opcodes, mnemonics and why we dont support them Oleg Nesterov
2014-05-06 17:01 ` Denys Vlasenko [this message]
2014-05-06 19:26 ` Oleg Nesterov
2014-05-05 22:32 ` Jim Keniston
2014-05-06 16:11 ` Denys Vlasenko
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