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From: Simon Horman <horms@verge.net.au>
To: Eugeniu Rosca <roscaeugeniu@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
	Chris Brandt <chris.brandt@renesas.com>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Ulrich Hecht <ulrich.hecht+renesas@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"George G . Davis" <george_davis@mentor.com>,
	Andy Lowe <andy_lowe@mentor.com>,
	linux-renesas-soc@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, Magnus Damm <magnus.damm@gmail.com>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Eugeniu Rosca <erosca@de.adit-jv.com>
Subject: Re: [PATCH 1/6] serial: sh-sci: Reveal ptrval in dev_dbg
Date: Mon, 6 May 2019 15:47:05 +0200	[thread overview]
Message-ID: <20190506134700.ya565idfzzc3enbm@verge.net.au> (raw)
In-Reply-To: <20190504004258.23574-2-erosca@de.adit-jv.com>

On Sat, May 04, 2019 at 02:42:53AM +0200, Eugeniu Rosca wrote:
> Starting with v4.15-rc2 commit ad67b74d2469d9 ("printk: hash addresses
> printed with %p"), enabling debug prints in sh-sci.c would generate
> output like below confusing the users who try to sneak into the
> internals of the driver:
> 
> sh-sci e6e88000.serial: sci_request_dma: TX: got channel (____ptrval____)
> sh-sci e6e88000.serial: sci_request_dma: mapped 4096@(____ptrval____) to 0x00000006798bf000
> sh-sci e6e88000.serial: sci_request_dma: RX: got channel (____ptrval____)
> sh-sci e6e88000.serial: sci_dma_tx_work_fn: (____ptrval____): 0...2, cookie 2
> 
> There are two possible fixes for that:
>  - get rid of '%p' prints if they don't reveal any useful information
>  - s/%p/%px/, since it is unlikely we have any concerns leaking the
>    pointer values when running a debug/non-production kernel

I am concerned that this may expose information in circumstances
where it is undesirable. Is it generally accepted practice to
use %px in conjunction with dev_dbg() ?

...

  reply	other threads:[~2019-05-06 13:47 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-04  0:42 [PATCH 0/6] Zap SCIF2 DMA configuration in R-Car Gen3 DTS Eugeniu Rosca
2019-05-04  0:42 ` [PATCH 1/6] serial: sh-sci: Reveal ptrval in dev_dbg Eugeniu Rosca
2019-05-06 13:47   ` Simon Horman [this message]
2019-05-06 15:24     ` Eugeniu Rosca
2019-05-06 16:46       ` Geert Uytterhoeven
2019-05-06 17:12         ` Eugeniu Rosca
2019-05-04  0:42 ` [PATCH 2/6] Revert "arm64: dts: renesas: r8a7796: Enable DMA for SCIF2" Eugeniu Rosca
2019-05-06 10:02   ` Geert Uytterhoeven
2019-05-06 19:42     ` Eugeniu Rosca
     [not found]       ` <1557413011-1662-1-git-send-email-george_davis@mentor.com>
2019-05-10 17:10         ` [PATCH] serial: sh-sci: disable DMA for uart_console Eugeniu Rosca
2019-05-10 18:38           ` George G. Davis
2019-05-13 10:28             ` Eugeniu Rosca
2019-05-13 11:13         ` Geert Uytterhoeven
2019-05-13 11:42           ` Simon Horman
2019-05-13 13:51         ` Wolfram Sang
2019-05-13 15:43           ` George G. Davis
2019-05-20  2:18       ` [PATCH 2/6] Revert "arm64: dts: renesas: r8a7796: Enable DMA for SCIF2" Yoshihiro Shimoda
2019-05-20  7:37         ` Geert Uytterhoeven
2019-05-20  9:52           ` Yoshihiro Shimoda
2019-05-04  0:42 ` [PATCH 3/6] arm64: dts: renesas: r8a7795: zap dma configuration in scif2 Eugeniu Rosca
2019-05-04  0:42 ` [PATCH 4/6] Revert "arm64: dts: renesas: r8a77965: Enable DMA for SCIF2" Eugeniu Rosca
2019-05-04  0:42 ` [PATCH 5/6] Revert "arm64: dts: renesas: r8a77990: " Eugeniu Rosca
2019-05-04  0:42 ` [PATCH 6/6] Revert "arm64: dts: renesas: r8a77995: add " Eugeniu Rosca

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