From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============5076034221161569263==" MIME-Version: 1.0 From: Fengguang Wu To: lkp@lists.01.org Subject: Re: [nand] BUG: unable to handle kernel NULL pointer dereference at 000005f4 Date: Mon, 14 Dec 2015 21:29:13 +0800 Message-ID: <20151214132913.GA1556@wfg-t540p.sh.intel.com> In-Reply-To: <20151214142259.7b24da20@bbrezillon> List-Id: --===============5076034221161569263== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable On Mon, Dec 14, 2015 at 02:22:59PM +0100, Boris Brezillon wrote: > On Mon, 14 Dec 2015 21:05:59 +0800 > Fengguang Wu wrote: > = > > Hi Boris, > > = > > On Mon, Dec 14, 2015 at 01:54:43PM +0100, Boris Brezillon wrote: > > > On Mon, 14 Dec 2015 14:45:37 +0800 > > > Fengguang Wu wrote: > > > = > > > > Hi Boris, > > > > = > > > > On Sun, Dec 13, 2015 at 09:50:43PM +0100, Boris Brezillon wrote: > > > > > Hi Fengguang, > > > > > = > > > > > On Sun, 13 Dec 2015 09:49:17 +0800 > > > > > Fengguang Wu wrote: > > > > > = > > > > > > Hi Boris, > > > > > > = > > > > > > FYI, this happened when merging your branch, which indicates po= ssible > > > > > > conflicts with other developer's patches or the new RC release. > > > > > = > > > > > Is this boot test also run on my bbrezillon-0day/nand/layering-re= work > > > > > branch (before merging it into devel-spot), and if it is, do you = see the > > > > > same error? > > > > = > > > > The bisect tests bbrezillon-0day/nand/layering-rework, however it's > > > > fine there. > > > > = > > > > > Is the devel-spot-201512102358 tag publicly accessible? If it's n= ot, > > > > = > > > > Nope. > > > > = > > > > > could you push it somewhere (or give me a way to generate it by > > > > > pulling the relevant branches), so that I can investigate on this= bug? = > > > > = > > > > Or it may be more convenient to check linux-next first? > > > > = > > > > FYI, the merged branches in devel-spot-201512102358 are: > > > > = > > > > af8fc33 Merge 'bbrezillon-0day/nand/layering-rework' into devel-spo= t-201512102358 > > > > acfc1de Merge 'linux-review/Maury-Markowitz/renaming-NTSC-file-beca= use-it-doesnt-actually-use-8VSV-updating-channel-listings-add-channel-numbe= rs/20151210-210449' into devel-spot-201512102358 > > > > fb9daac Merge 'fdmanana/integration-4.4' into devel-spot-2015121023= 58 > > > > 1b30725 Merge 'fdmanana/for-chris-4.4' into devel-spot-201512102358 > > > > 83f2246 Merge 'arm-integrator/realview-defconfig' into devel-spot-2= 01512102358 > > > > 03df745 Merge 'arm-integrator/realview-multiplatform-base' into dev= el-spot-201512102358 > > > > d2aea29 Merge 'linux-review/Arnd-Bergmann/i2c-allow-building-emev2-= without-slave-mode-again/20151210-211642' into devel-spot-201512102358 > > > > e2f041d Merge 'arm-integrator/realview-base-armsoc' into devel-spot= -201512102358 > > > > 5c46550 Merge 'linux-review/Bert-Kenward/sfc-only-use-RSS-filters-i= f-we-re-using-RSS/20151210-213247' into devel-spot-201512102358 > > > > d07f80f Merge 'sound/test/hdmi-jack' into devel-spot-201512102358 > > > > 540f8b7 Merge 'sound/topic/hdmi-jack' into devel-spot-201512102358 > > > > 9111fa0 Merge 'linux-review/matrandg-cisco-com/tc358743-Use-local-a= rray-with-fixed-size-in-i2c-write/20151210-214154' into devel-spot-20151210= 2358 > > > > 3d81ef9 Merge 'linux-review/matrandg-cisco-com/tc358743-Print-timin= gs-only-when-debug-level-is-set/20151210-220321' into devel-spot-2015121023= 58 > > > > 122e43c Merge 'bbrezillon-0day/nand/ecclayout-squashed' into devel-= spot-201512102358 > > > > e0572f8 Merge 'wireless-drivers-next/pending' into devel-spot-20151= 2102358 > > > > dc5d9c9 Merge 'linux-review/Geliang-Tang/list-introduce-list_is_fir= st/20151210-222552' into devel-spot-201512102358 > > > > 289e2a8 Merge 'linux-review/Arnd-Bergmann/staging-davinci_vfpe-allo= w-modular-build/20151210-223348' into devel-spot-201512102358 > > > > d74c50d Merge 'linux-review/Damien-Horsley/Add-driver-for-Pistachio= -internal-DAC/20151210-224304' into devel-spot-201512102358 > > > > ee3c58b Merge 'cryptodev/master' into devel-spot-201512102358 > > > > d390f7d Merge 'linux-review/John-Garry/hisi_sas-use-platform_get_ir= q/20151210-224851' into devel-spot-201512102358 > > > > de31f5d Merge 'linux-review/Mike-Marciniszyn/staging-rdma-hfi1-add-= definitions-for-OPA-traps/20151210-230158' into devel-spot-201512102358 > > > > 5618568 Merge 'linux-review/Andrei-Emeltchenko/Bluetooth-h5-Do-not-= initialize-Configuration-field/20151210-230440' into devel-spot-201512102358 > > > > 759aa32 Merge 'linux-review/Moritz-K-nig/staging-COMEDI-checkpatch-= pl-cleanups-in-comedi-h/20151210-230707' into devel-spot-201512102358 > > > > 2edcbb4 Merge 'linux-review/Andy-Shevchenko/net-hns-annotate-IO-add= ress-space-properly/20151210-232510' into devel-spot-201512102358 > > > > 0f51fdd Merge 'integrity/next-kexec' into devel-spot-201512102358 > > > > b32bcbc Merge 'dm/dm-4.5' into devel-spot-201512102358 > > > > ea297f5 Merge 'linux-review/Mathieu-Desnoyers/thread_local_abi-syst= em-call-caching-current-CPU-number-x86/20151210-234242' into devel-spot-201= 512102358 > > > > 52bc163 Merge 'linux-review/yegorslists-googlemail-com/USB-serial-o= ption-add-support-for-Quectel-UC20/20151210-234659' into devel-spot-2015121= 02358 > > > > 797cc7c Merge 'linux-review/Andy-Shevchenko/staging-rtl8188eu-provi= de-an-absolute-path-to-include-folder/20151210-234752' into devel-spot-2015= 12102358 > > > > 23d8b49 Merge 'omap-dss2/for-next' into devel-spot-201512102358 > > > > 88a768f 0day base guard for 'devel-spot-201512102358' > > > > 527e931 Linux 4.4-rc4 > > > > = > > > = > > > Okay, I think I found the problem: you're pulling > > > bbrezillon-0day/nand/ecclayout-squashed and then > > > bbrezillon-0day/nand/layering-rework. Those branches are both based on > > > Brian's l2-mtd/master branch, and are both changing NAND subsystem > > > internals. IOW, the changes brought by nand/ecclayout-squashed are > > > introducing new "mtd->priv" occurrences, while the goal of > > > nand/layering-rework is to replace them by mtd_to_nand(mtd) and kill > > > the mtd->priv =3D xxx assignments, hence the NULL pointer exception. > > = > > Ah got it, sorry for the noises! > > = > > > I guess I'm the one responsible for this false positive, because I > > > pushed two non-independent branches in my 0day tree. > > > I could rebase my nand/ecclayout-squashed branch and fix all the faul= ty > > > places, but that implies reordering your pull commands > > > (nand/layering-rework before nand/ecclayout-squashed). Would that work > > > for you? Any other suggestions to gracefully handle this kind of > > > dependencies? > > = > > There is no much to do about such dependencies. One possible fix is to > > improve the 0day system to bisect the conflicting merges, which should > > save the lots of manual efforts to locate the problem. I've put it as > > a TODO item. > = > Okay, I think I'll temporary kill the nand/ecclayout-squashed branch > until I've properly rebased it on top of the nand/layering-rework one, > so that you can still tests changes coming from other trees. OK, thank you very much! Thanks, Fengguang --===============5076034221161569263==--