From: Oleg Nesterov <oleg@redhat.com>
To: Anton Arapov <anton@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
LKML <linux-kernel@vger.kernel.org>,
Josh Stone <jistone@redhat.com>, Frank Eigler <fche@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@elte.hu>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Subject: Re: [RFC PATCH v3 5/6] uretprobes: invoke return probe handlers
Date: Sat, 2 Mar 2013 19:09:39 +0100 [thread overview]
Message-ID: <20130302180939.GA32596@redhat.com> (raw)
In-Reply-To: <1362049215-5780-6-git-send-email-anton@redhat.com>
On 02/28, Anton Arapov wrote:
>
> @@ -1576,8 +1622,8 @@ static void handle_swbp(struct pt_regs *regs)
>
> if (!uprobe) {
> if (is_swbp > 0) {
> - /* No matching uprobe; signal SIGTRAP. */
> - send_sig(SIGTRAP, current, 0);
> + /* No matching uprobe; Try with uretprobe */
> + handle_uretprobe(regs);
Hmm. at least this looks certainly wrong.
You shifted send_sig(SIGSEGV) into handle_uretprobe(), but if nothing
else printk(KERN_ERR "uprobe: no instance found!") doesn't look nice
if we hit the regular breakoint.
In fact everything handle_uretprobe() does in this case looks wrong.
Including the fact that get_xol_area/get_utask can fail. And unwinding
looks bogus...
I think you need
if (bp_vaddr == rp_trampoline_vaddr)
handle_uretprobe()
like the previous version did.
Oleg.
next prev parent reply other threads:[~2013-03-02 18:11 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-28 11:00 [RFC PATCH v3 0/6] uprobes: return probe implementation Anton Arapov
2013-02-28 11:00 ` [RFC PATCH v3 1/6] uretprobes: preparation patch Anton Arapov
2013-02-28 11:00 ` [RFC PATCH v3 2/6] uretprobes/x86: hijack return address Anton Arapov
2013-03-01 5:45 ` Ananth N Mavinakayanahalli
2013-03-01 11:00 ` Anton Arapov
2013-03-01 11:21 ` Ananth N Mavinakayanahalli
2013-02-28 11:00 ` [RFC PATCH v3 3/6] uretprobes: generalize xol_get_insn_slot() Anton Arapov
2013-02-28 20:01 ` Oleg Nesterov
2013-02-28 11:00 ` [RFC PATCH v3 4/6] uretprobes: return probe entry, prepare uretprobe Anton Arapov
2013-02-28 20:10 ` Oleg Nesterov
2013-03-04 14:14 ` Anton Arapov
2013-03-02 18:26 ` Oleg Nesterov
2013-03-03 16:40 ` Oleg Nesterov
2013-03-04 10:49 ` Anton Arapov
2013-02-28 11:00 ` [RFC PATCH v3 5/6] uretprobes: invoke return probe handlers Anton Arapov
2013-03-02 18:09 ` Oleg Nesterov [this message]
2013-02-28 11:00 ` [RFC PATCH v3 6/6] uretprobes: implemented, thus remove -ENOSYS Anton Arapov
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