From: Steven Rostedt <rostedt@goodmis.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
Song Liu <liu.song.a23@gmail.com>,
srikar@linux.vnet.ibm.com, mhiramat@kernel.org,
Peter Zijlstra <peterz@infradead.org>,
mingo@redhat.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, jolsa@redhat.com,
namhyung@kernel.org, open list <linux-kernel@vger.kernel.org>,
ananth@linux.vnet.ibm.com,
Alexis Berlemont <alexis.berlemont@gmail.com>,
naveen.n.rao@linux.vnet.ibm.com,
linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org,
linux@armlinux.org.uk, ralf@linux-mips.org, paul.burton@mips.com
Subject: Re: [PATCH v8 3/6] Uprobes: Support SDT markers having reference count (semaphore)
Date: Mon, 13 Aug 2018 20:03:59 -0400 [thread overview]
Message-ID: <20180813200359.31311bbb@gandalf.local.home> (raw)
In-Reply-To: <20180813115019.GB28360@redhat.com>
On Mon, 13 Aug 2018 13:50:19 +0200
Oleg Nesterov <oleg@redhat.com> wrote:
> On 08/13, Ravi Bangoria wrote:
> >
> > On 08/11/2018 01:27 PM, Song Liu wrote:
> > >> +
> > >> +static void delayed_uprobe_delete(struct delayed_uprobe *du)
> > >> +{
> > >> + if (!du)
> > >> + return;
> > > Do we really need this check?
> >
> > Not necessary though, but I would still like to keep it for a safety.
>
> Heh. I tried to ignore all minor problems in this version, but now that Song
> mentioned this unnecessary check...
>
> Personally I really dislike the checks like this one.
>
> - It can confuse the reader who will try to understand the purpose
>
> - it can hide a bug if delayed_uprobe_delete(du) is actually called
> with du == NULL.
>
> IMO, you should either remove it and let the kernel crash (to notice the
> problem), or turn it into
>
> if (WARN_ON(!du))
> return;
I'd prefer the more robust WARN_ON(!du) above instead of removing it.
-- Steve
next prev parent reply other threads:[~2018-08-14 0:04 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-09 4:18 [PATCH v8 0/6] Uprobes: Support SDT markers having reference count (semaphore) Ravi Bangoria
2018-08-09 4:18 ` [PATCH v8 1/6] Uprobes: Simplify uprobe_register() body Ravi Bangoria
2018-08-11 8:00 ` Song Liu
2018-08-13 8:56 ` Srikar Dronamraju
2018-08-14 0:07 ` Steven Rostedt
2018-08-09 4:18 ` [PATCH v8 2/6] Uprobe: Additional argument arch_uprobe to uprobe_write_opcode() Ravi Bangoria
2018-08-11 8:01 ` Song Liu
2018-08-13 8:51 ` Srikar Dronamraju
2018-08-09 4:18 ` [PATCH v8 3/6] Uprobes: Support SDT markers having reference count (semaphore) Ravi Bangoria
2018-08-09 14:38 ` Oleg Nesterov
2018-08-10 19:58 ` Steven Rostedt
2018-08-11 6:14 ` Song Liu
2018-08-14 0:01 ` Steven Rostedt
2018-08-14 0:05 ` Steven Rostedt
2018-08-11 7:57 ` Song Liu
2018-08-11 15:37 ` Steven Rostedt
2018-08-13 5:47 ` Ravi Bangoria
2018-08-13 7:38 ` Ravi Bangoria
2018-08-13 11:50 ` Oleg Nesterov
2018-08-13 13:01 ` Ravi Bangoria
2018-08-13 13:17 ` Oleg Nesterov
2018-08-13 14:26 ` Ravi Bangoria
2018-08-13 14:51 ` Oleg Nesterov
2018-08-13 17:12 ` Song Liu
2018-08-14 4:37 ` Ravi Bangoria
2018-08-14 16:35 ` Song Liu
2018-08-14 0:03 ` Steven Rostedt [this message]
2018-08-13 16:50 ` Song Liu
2018-08-13 10:03 ` Srikar Dronamraju
2018-08-13 11:23 ` Oleg Nesterov
2018-08-14 8:56 ` Ravi Bangoria
2018-08-09 4:18 ` [PATCH v8 4/6] Uprobes/sdt: Prevent multiple reference counter for same uprobe Ravi Bangoria
2018-08-11 8:04 ` Song Liu
2018-08-13 8:50 ` Srikar Dronamraju
2018-08-09 4:18 ` [PATCH v8 5/6] trace_uprobe/sdt: " Ravi Bangoria
2018-08-11 8:12 ` Song Liu
2018-08-13 8:19 ` Ravi Bangoria
2018-08-13 8:49 ` Srikar Dronamraju
2018-08-13 16:27 ` Song Liu
2018-08-13 8:48 ` Srikar Dronamraju
2018-08-09 4:18 ` [PATCH v8 6/6] perf probe: Support SDT markers having reference counter (semaphore) Ravi Bangoria
2018-08-13 16:55 ` [PATCH v8 0/6] Uprobes: Support SDT markers having reference count (semaphore) Oleg Nesterov
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