From: Doug Anderson <dianders@chromium.org>
To: Cengiz Can <cengiz@kernel.wtf>
Cc: Daniel Thompson <daniel.thompson@linaro.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Jason Wessel <jason.wessel@windriver.com>,
kgdb-bugreport@lists.sourceforge.net,
LKML <linux-kernel@vger.kernel.org>,
Petr Mladek <pmladek@suse.com>,
Sumit Garg <sumit.garg@linaro.org>
Subject: Re: [PATCH v2] kdb: remove unnecessary null check of dbg_io_ops
Date: Mon, 29 Jun 2020 14:16:39 -0700 [thread overview]
Message-ID: <CAD=FV=XWYKqHEMDt-0PYHty_syJ9MO6Oz8DVBbacNZS5zGXk9A@mail.gmail.com> (raw)
In-Reply-To: <20200629205012.3263-1-cengiz@kernel.wtf>
Hi,
On Mon, Jun 29, 2020 at 1:50 PM Cengiz Can <cengiz@kernel.wtf> wrote:
>
> `kdb_msg_write` operates on a global `struct kgdb_io *` called
> `dbg_io_ops`.
>
> It's initialized in `debug_core.c` and checked throughout the debug
> flow.
>
> There's a null check in `kdb_msg_write` which triggers static analyzers
> and gives the (almost entirely wrong) impression that it can be null.
>
> Coverity scanner caught this as CID 1465042.
>
> I have removed the unnecessary null check and eliminated false-positive
> forward null dereference warning.
>
> Signed-off-by: Cengiz Can <cengiz@kernel.wtf>
> ---
> kernel/debug/kdb/kdb_io.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
> index 683a799618ad..4ac59a4fbeec 100644
> --- a/kernel/debug/kdb/kdb_io.c
> +++ b/kernel/debug/kdb/kdb_io.c
> @@ -549,14 +549,12 @@ static void kdb_msg_write(const char *msg, int msg_len)
> if (msg_len == 0)
> return;
>
> - if (dbg_io_ops) {
> - const char *cp = msg;
> - int len = msg_len;
> + const char *cp = msg;
> + int len = msg_len;
kernel/debug/kdb/kdb_io.c:552:14:
warning: ISO C90 forbids mixing declarations and code
[-Wdeclaration-after-statement]
-Doug
next prev parent reply other threads:[~2020-06-29 21:16 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-29 13:59 [PATCH] kdb: prevent possible null deref in kdb_msg_write Cengiz Can
2020-06-29 14:27 ` Daniel Thompson
2020-06-29 14:50 ` Petr Mladek
2020-06-29 14:53 ` Petr Mladek
2020-06-29 15:37 ` Daniel Thompson
2020-06-29 20:50 ` [PATCH v2] kdb: remove unnecessary null check of dbg_io_ops Cengiz Can
2020-06-29 21:16 ` Doug Anderson [this message]
2020-06-29 22:10 ` Cengiz Can
2020-06-30 5:55 ` [PATCH] kdb: prevent possible null deref in kdb_msg_write Sumit Garg
2020-06-30 8:29 ` [PATCH v3] kdb: remove unnecessary null check of dbg_io_ops Cengiz Can
2020-06-30 11:36 ` Sumit Garg
2020-06-30 11:48 ` Andy Shevchenko
2020-06-30 22:32 ` Doug Anderson
2020-07-10 12:15 ` Cengiz Can
2020-07-10 13:41 ` Daniel Thompson
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