From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: Query: ARM64: Behavior of el1_dbg exception while executing el0_dbg
Date: Thu, 8 Jan 2015 16:23:13 +0000 [thread overview]
Message-ID: <20150108162312.GO11583@arm.com> (raw)
In-Reply-To: <54AE830E.1090000@redhat.com>
On Thu, Jan 08, 2015 at 01:15:58PM +0000, Pratyush Anand wrote:
> Hi All,
>
> I am trying to test following scenario, which seems valid to me. But I
> am very new to ARM64 as well as to debugging tools, so seeking expert's
> comment here.
>
> -- I have inserted a kprobe to the function uprobe_breakpoint_handler
> which is called from elo_dbg
> (el0_dbg->do_debug_exception->brk_handler->call_break_hook->uprobe_breakpoint_handler)
>
> -- kprobe is enabled.
>
> -- an uprobe is inserted into a test application and enabled.
>
> So, when uprobe is enabled and test code execution reaches to probe
> instruction, it executes uprobe breakpoint instruction and el0_dbg
> exception is raised.
>
> When control reaches to start of uprobe_breakpoint_handler and it
> executes first instruction (which has been replaced with a kprobe
> breakpoint instruction), el1_dbg exception is raised.
Hmm, debug exceptions should be masked at this point so I don't see why
you're taking the second debug exception.
Will
next prev parent reply other threads:[~2015-01-08 16:23 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-08 13:15 Query: ARM64: Behavior of el1_dbg exception while executing el0_dbg Pratyush Anand
2015-01-08 15:49 ` William Cohen
2015-01-08 17:19 ` Pratyush Anand
2015-01-08 16:23 ` Will Deacon [this message]
2015-01-08 17:28 ` Pratyush Anand
2015-01-09 15:46 ` Will Deacon
2015-01-09 17:13 ` Pratyush Anand
2015-01-12 17:30 ` Will Deacon
2015-01-12 19:25 ` William Cohen
2015-01-13 6:46 ` Pratyush Anand
2015-01-13 15:52 ` Catalin Marinas
2015-01-13 17:53 ` Pratyush Anand
2015-01-15 16:47 ` Pratyush Anand
2015-01-16 12:00 ` Pratyush Anand
2015-01-16 14:55 ` Pratyush Anand
2015-01-16 16:22 ` Will Deacon
2015-01-19 6:10 ` Pratyush Anand
2015-01-19 10:11 ` Will Deacon
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