From: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
To: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kretprobes: reject registration if a symbol offset is specified
Date: Tue, 14 Feb 2017 14:11:03 +0530 [thread overview]
Message-ID: <20170214084103.GF29806@in.ibm.com> (raw)
In-Reply-To: <57139b36e50748ad931d66658bed62b29280c8c2.1487060504.git.naveen.n.rao@linux.vnet.ibm.com>
On Tue, Feb 14, 2017 at 02:01:18PM +0530, Naveen N. Rao wrote:
> Users shouldn't be able to specify an offset with kretprobes, as we always
> want to probe at function entry. Otherwise, we won't be able to capture
> the proper return address resulting in the kretprobe never firing.
>
> With samples/kprobes/kretprobe_example.c including an offset:
> my_kretprobe.kp.offset = 40;
>
> Before this patch, the probe gets planted but never fires.
>
> After this patch:
> $ sudo insmod samples/kprobes/kretprobe_example.ko
> [sudo] password for naveen:
> insmod: ERROR: could not insert module samples/kprobes/kretprobe_example.ko: Operation not permitted
>
> And dmesg:
> [48253.757629] register_kretprobe failed, returned -22
>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
next prev parent reply other threads:[~2017-02-14 8:41 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-14 8:31 [PATCH] kretprobes: reject registration if a symbol offset is specified Naveen N. Rao
2017-02-14 8:41 ` Ananth N Mavinakayanahalli [this message]
2017-02-14 10:32 ` Masami Hiramatsu
2017-02-15 17:53 ` Naveen N. Rao
2017-02-15 18:17 ` [PATCH 1/3] kretprobes: ensure probe location is at function entry Naveen N. Rao
2017-02-15 18:17 ` [PATCH 2/3] trace/kprobes: allow return probes with offsets and absolute addresses Naveen N. Rao
2017-02-15 23:43 ` Masami Hiramatsu
2017-02-15 18:17 ` [PATCH 3/3] perf: revert "perf probe: Fix probing kretprobes" Naveen N. Rao
2017-02-15 23:43 ` Masami Hiramatsu
2017-02-15 23:39 ` [PATCH 1/3] kretprobes: ensure probe location is at function entry Masami Hiramatsu
2017-02-16 7:51 ` Naveen N. Rao
2017-02-16 8:17 ` [PATCH 0/2] powerpc: kretprobe updates Naveen N. Rao
2017-02-16 8:17 ` [PATCH 1/2] powerpc: kretprobes: override default function entry offset Naveen N. Rao
2017-02-16 8:17 ` [PATCH 2/2] perf: powerpc: choose LEP with kretprobes Naveen N. Rao
2017-02-17 10:44 ` [PATCH 0/2] powerpc: kretprobe updates Masami Hiramatsu
2017-02-17 20:42 ` Arnaldo Carvalho de Melo
2017-02-19 4:42 ` Masami Hiramatsu
2017-02-20 9:50 ` Naveen N. Rao
2017-02-21 13:07 ` Masami Hiramatsu
2017-02-22 13:39 ` Naveen N. Rao
2017-02-20 9:46 ` Naveen N. Rao
2017-02-20 11:43 ` Naveen N. Rao
2017-02-21 13:06 ` Masami Hiramatsu
2017-02-15 23:28 ` [PATCH] kretprobes: reject registration if a symbol offset is specified Masami Hiramatsu
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