From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
To: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
oleg@redhat.com, lkml <linux-kernel@vger.kernel.org>,
Paul Mackerras <paulus@samba.org>,
Anton Blanchard <anton@samba.org>, Ingo Molnar <mingo@elte.hu>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 2/2] [POWERPC] uprobes: powerpc port
Date: Fri, 8 Jun 2012 10:06:05 +0530 [thread overview]
Message-ID: <20120608043605.GB13409@in.ibm.com> (raw)
In-Reply-To: <1339006084.3458.25.camel@localhost>
On Wed, Jun 06, 2012 at 11:08:04AM -0700, Jim Keniston wrote:
> On Wed, 2012-06-06 at 15:05 +0530, Ananth N Mavinakayanahalli wrote:
> > On Wed, Jun 06, 2012 at 11:27:02AM +0200, Peter Zijlstra wrote:
> > > On Wed, 2012-06-06 at 14:51 +0530, Ananth N Mavinakayanahalli wrote:
...
> > For the kernel, the only ones that are off limits are rfi (return from
> > interrupt), mtmsr (move to msr). All other instructions can be probed.
> >
> > Both those instructions are supervisor level, so we won't see them in
> > userspace at all; so we should be able to probe all user level
> > instructions.
>
> Presumably rfi or mtmsr could show up in the instruction stream via an
> erroneous or mischievous asm statement. It'd be good to verify that you
> handle that gracefully.
That'd be flagged elsewhere, by the architecture itself -- you'd get a
privileged instruciton exception if you try execute any instruction not
part of the UISA. I therefore don't think its a necessary check in the
uprobes code.
Ananth
next prev parent reply other threads:[~2012-06-08 4:36 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-06 9:19 [PATCH 1/2] uprobes: Pass probed vaddr to arch_uprobe_analyze_insn() Ananth N Mavinakayanahalli
2012-06-06 9:21 ` [PATCH 2/2] [POWERPC] uprobes: powerpc port Ananth N Mavinakayanahalli
2012-06-06 9:27 ` Peter Zijlstra
2012-06-06 9:35 ` Ananth N Mavinakayanahalli
2012-06-06 18:08 ` Jim Keniston
2012-06-08 4:36 ` Ananth N Mavinakayanahalli [this message]
2012-06-08 5:51 ` Michael Ellerman
2012-06-08 6:01 ` Ananth N Mavinakayanahalli
2012-06-08 6:17 ` Michael Ellerman
2012-06-08 6:19 ` Ananth N Mavinakayanahalli
2012-06-08 6:38 ` Michael Ellerman
2012-06-08 9:21 ` Ananth N Mavinakayanahalli
2012-06-12 4:01 ` Michael Ellerman
2012-06-12 4:52 ` Ananth N Mavinakayanahalli
2012-06-06 9:23 ` [PATCH 1/2] uprobes: Pass probed vaddr to arch_uprobe_analyze_insn() Peter Zijlstra
2012-06-06 9:37 ` Ananth N Mavinakayanahalli
2012-06-06 9:40 ` Ingo Molnar
2012-06-06 10:22 ` Ananth N Mavinakayanahalli
2012-06-06 11:44 ` Srikar Dronamraju
2012-06-08 4:33 ` Ananth N Mavinakayanahalli
2012-06-06 15:08 ` Oleg Nesterov
2012-06-06 16:30 ` Srikar Dronamraju
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