lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 11 Dec 2015 18:08:55 +0100 From: Boris Brezillon <boris.brezillon@...e-electrons.com> To: Dinh Nguyen <dinh.linux@...il.com> Cc: David Woodhouse <dwmw2@...radead.org>, Brian Norris <computersforpeace@...il.com>, linux-mtd@...ts.infradead.org, Andrew Lunn <andrew@...n.ch>, Krzysztof Kozlowski <k.kozlowski@...sung.com>, "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>, Tony Lindgren <tony@...mide.com>, Nicolas Ferre <nicolas.ferre@...el.com>, Stefan Agner <stefan@...er.ch>, linux-sunxi@...glegroups.com, Alexandre Belloni <alexandre.belloni@...e-electrons.com>, Robert Jarzmik <robert.jarzmik@...e.fr>, Alexander Clouter <alex@...riz.org.uk>, "devel@...verdev.osuosl.org" <devel@...verdev.osuosl.org>, Jesper Nilsson <jesper.nilsson@...s.com>, linux-samsung-soc@...r.kernel.org, Maxim Levitsky <maximlevitsky@...il.com>, Jonathan Corbet <corbet@....net>, Marek Vasut <marek.vasut@...il.com>, Chen-Yu Tsai <wens@...e.org>, Kukjin Kim <kgene@...nel.org>, Ezequiel Garcia <ezequiel.garcia@...e-electrons.com>, Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>, Dinh Nguyen <dinguyen@...era.com>, Sebastian Hesselbarth <sebastian.hesselbarth@...il.com>, Jason Cooper <jason@...edaemon.net>, Wan ZongShun <mcuos.com@...il.com>, Steven Miao <realmz6@...il.com>, Haojian Zhuang <haojian.zhuang@...il.com>, Mikael Starvik <starvik@...s.com>, Krzysztof Halasa <khalasa@...p.pl>, Gregory CLEMENT <gregory.clement@...e-electrons.com>, linux-omap@...r.kernel.org, "linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>, Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>, Ryan Mallon <rmallon@...il.com>, linux-cris-kernel@...s.com, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Linux List <linux-kernel@...r.kernel.org>, Hartley Sweeten <hsweeten@...ionengravers.com>, Dan Carpenter <dan.carpenter@...cle.com>, Sascha Hauer <kernel@...gutronix.de>, Maxime Ripard <maxime.ripard@...e-electrons.com>, Imre Kaloz <kaloz@...nwrt.org>, Shawn Guo <shawnguo@...nel.org>, Daniel Mack <daniel@...que.org> Subject: Re: [PATCH v5 01/58] mtd: nand: denali: add missing nand_release() call in denali_remove() Hi Dinh, On Fri, 11 Dec 2015 10:50:21 -0600 Dinh Nguyen <dinh.linux@...il.com> wrote: > Hi Boris, > > On Fri, Dec 11, 2015 at 9:10 AM, Boris Brezillon > <boris.brezillon@...e-electrons.com> wrote: > > + Dinh (who made commit 2a0a288ec258) > > > > Also added back the Fixes tag. > > > > On Fri, 11 Dec 2015 15:02:34 +0100 > > Boris Brezillon <boris.brezillon@...e-electrons.com> wrote: > > > >> Unregister the NAND device from the NAND subsystem when removing a denali > >> NAND controller, otherwise the MTD attached to the NAND device is still > >> exposed by the MTD layer, and accesses to this device will likely crash > >> the system. > >> > >> Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com> > > > > Fixes: 2a0a288ec258 ("mtd: denali: split the generic driver and PCI layer") > > > >> --- > >> Changes since v4: > >> - remove Cc stable and fixes tags > >> - calculate the dma buffer size before calling nand_release() > >> > >> drivers/mtd/nand/denali.c | 6 ++++-- > >> 1 file changed, 4 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c > >> index 67eb2be..fdfea05 100644 > >> --- a/drivers/mtd/nand/denali.c > >> +++ b/drivers/mtd/nand/denali.c > >> @@ -1622,9 +1622,11 @@ EXPORT_SYMBOL(denali_init); > >> /* driver exit point */ > >> void denali_remove(struct denali_nand_info *denali) > >> { > >> + int bufsize = denali->mtd.writesize + denali->mtd.oobsize; > >> + > >> + nand_release(&denali->mtd); > >> denali_irq_cleanup(denali->irq, denali); > >> - dma_unmap_single(denali->dev, denali->buf.dma_buf, > >> - denali->mtd.writesize + denali->mtd.oobsize, > >> + dma_unmap_single(denali->dev, denali->buf.dma_buf, bufsize, > >> DMA_BIDIRECTIONAL); > > Not sure what is the need to add bufsize here, but the commit message > doesn't reflect the change. You were not in Cc of the first version (my fault), but Brian pointed that the mtd fields could be in an unknown state after the nand_release() call (this is currently not the case, but it change in the future). The idea is to pre-compute the DMA buffer size before releasing the mtd/nand device to prevent any future issues. I don't think it is worth mentioning this in the commit message, because these are just implementation details, but I can add the following comment before the bufsize declaration: /* * Pre-compute DMA buffer size to avoid any problems in case * nand_release() ever changes in a way that mtd->writesize and * mtd->oobsize are not reliable after this call. */ What do you think? Best Regards, Boris > > Dinh -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists