From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
Anton Arapov <anton@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Roland McGrath <roland@hack.frob.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 8/7] uprobes: Fix arch_uprobe_disable_step() && UTASK_SSTEP_TRAPPED interaction
Date: Wed, 12 Sep 2012 18:06:00 +0530 [thread overview]
Message-ID: <20120912123600.GD9582@linux.vnet.ibm.com> (raw)
In-Reply-To: <20120908170623.GB19311@redhat.com>
* Oleg Nesterov <oleg@redhat.com> [2012-09-08 19:06:23]:
> arch_uprobe_disable_step() should also take UTASK_SSTEP_TRAPPED into
> account. In this case the probed insn was not executed, we need to
> clear X86_EFLAGS_TF if it was set by us and that is all.
>
> Again, this code will look more clean when we move it into
> arch_uprobe_post_xol() and arch_uprobe_abort_xol().
>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
note:
I also think this should be merged into 6/7 patch if possible
--
thanks and regards
Srikar
> ---
> arch/x86/kernel/uprobes.c | 14 ++++++++++----
> 1 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
> index 7e993d1..9538f00 100644
> --- a/arch/x86/kernel/uprobes.c
> +++ b/arch/x86/kernel/uprobes.c
> @@ -706,14 +706,20 @@ void arch_uprobe_disable_step(struct arch_uprobe *auprobe)
> {
> struct task_struct *task = current;
> struct arch_uprobe_task *autask = &task->utask->autask;
> + bool trapped = (task->utask->state == UTASK_SSTEP_TRAPPED);
> struct pt_regs *regs = task_pt_regs(task);
> /*
> * The state of TIF_BLOCKSTEP was not saved so we can get an extra
> * SIGTRAP if we do not clear TF. We need to examine the opcode to
> * make it right.
> */
> - if (autask->saved_tf)
> - send_sig(SIGTRAP, task, 0);
> - else if (!(auprobe->fixups & UPROBE_FIX_SETF))
> - regs->flags &= ~X86_EFLAGS_TF;
> + if (unlikely(trapped)) {
> + if (!autask->saved_tf)
> + regs->flags &= ~X86_EFLAGS_TF;
> + } else {
> + if (autask->saved_tf)
> + send_sig(SIGTRAP, task, 0);
> + else if (!(auprobe->fixups & UPROBE_FIX_SETF))
> + regs->flags &= ~X86_EFLAGS_TF;
> + }
> }
> --
> 1.5.5.1
>
>
next prev parent reply other threads:[~2012-09-12 12:40 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-03 15:25 [PATCH 0/7] uprobes: single-step fixes Oleg Nesterov
2012-09-03 15:25 ` [PATCH 1/7] uprobes: Introduce arch_uprobe_enable/disable_step() Oleg Nesterov
2012-09-07 14:57 ` Srikar Dronamraju
2012-09-03 15:26 ` [PATCH 2/7] uprobes: x86: Implement x86 specific arch_uprobe_*_step Oleg Nesterov
2012-09-07 14:59 ` Srikar Dronamraju
2012-09-03 15:26 ` [PATCH 3/7] ptrace: Introduce set_task_blockstep() helper Oleg Nesterov
2012-09-07 15:00 ` Srikar Dronamraju
2012-09-03 15:26 ` [PATCH 4/7] ptrace: Partly fix set_task_blockstep()->update_debugctlmsr() logic Oleg Nesterov
2012-09-07 15:14 ` Srikar Dronamraju
2012-09-10 16:57 ` Sebastian Andrzej Siewior
2012-09-10 17:45 ` Peter Zijlstra
2012-09-10 17:27 ` Oleg Nesterov
2012-09-03 15:26 ` [PATCH 5/7] uprobes: Do not (ab)use TIF_SINGLESTEP/user_*_single_step() for single-stepping Oleg Nesterov
2012-09-07 15:11 ` Srikar Dronamraju
2012-09-07 15:50 ` Oleg Nesterov
2012-09-08 7:49 ` Srikar Dronamraju
2012-09-03 15:26 ` [PATCH 6/7] uprobes: Xol should send SIGTRAP if X86_EFLAGS_TF was set Oleg Nesterov
2012-09-12 12:08 ` Srikar Dronamraju
2012-09-12 14:45 ` Oleg Nesterov
2012-09-03 15:26 ` [PATCH 7/7] uprobes: Make arch_uprobe_task->saved_trap_nr "unsigned int" Oleg Nesterov
2012-09-12 12:27 ` Srikar Dronamraju
2012-09-08 17:06 ` [PATCH 0/7] uprobes: single-step fixes Oleg Nesterov
2012-09-12 12:33 ` Srikar Dronamraju
2012-09-08 17:06 ` [PATCH 8/7] uprobes: Fix arch_uprobe_disable_step() && UTASK_SSTEP_TRAPPED interaction Oleg Nesterov
2012-09-12 12:36 ` Srikar Dronamraju [this message]
2012-09-10 16:57 ` [PATCH 0/7] uprobes: single-step fixes Sebastian Andrzej Siewior
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