Date: Thu, 5 Jan 2006 02:51:30 -0800
From: Stephane Eranian <eranian@hpl.hp.com>
To: linux-kernel@vger.kernel.org
Cc: Stephane Eranian <eranian@hpl.hp.com>
Subject: ptrace denies access to EFLAGS_RF
Message-ID: <20060105105130.GC3712@frankl.hpl.hp.com>
Reply-To: eranian@hpl.hp.com
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Hello,

I am trying to the user HW debug registers on i386
and I am running into a problem with ptrace() not allowing access
to EFLAGS_RF for POKEUSER (see FLAG_MASK).

I am not sure I understand the motivation for denying access
to this flag which can be used to resume after a code
breakpoint has been reached. It avoids the need to remove the
breakpoint, single step, and reinstall. The equivalent
functionality exists on IA-64 and is allowed by ptrace().

Why is EFLAGS_RF not accessible to users on i386?

Thanks.

-- 
-Stephane
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