Hi, Can you please provide more details. I don't understand how this patch can cause boot failure.
>From the log found at https://storage.kernelci.org/mainline/master/v4.20-rc5-79-gabb8d6ecbd8f/arm/multi_v7_defconfig+CONFIG_EFI=y+CONFIG_ARM_LPAE=y/lab-baylibre/boot-tegra124-jetson-tk1.html 23:21:06.680269 [ 7.500733] Unable to handle kernel NULL pointer dereference at virtual address 00000064 23:21:06.680455 [ 7.508893] pgd = (ptrval) 23:21:06.721940 [ 7.511591] [00000064] *pgd=ad7d8003, *pmd=f9d5d003 23:21:06.722241 [ 7.516500] Internal error: Oops: 207 [#1] SMP ARM ... 23:21:06.722724 [ 7.546706] CPU: 0 PID: 122 Comm: udevd Not tainted 4.20.0-rc5 #1 23:21:06.722911 [ 7.552785] Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) 23:21:06.765203 [ 7.559045] PC is at drm_plane_register_all+0x18/0x50 23:21:06.765493 [ 7.564094] LR is at drm_modeset_register_all+0xc/0x6c 23:21:06.765698 [ 7.569217] pc : [<c09a8700>] lr : [<c09ab240>] psr: a0000013 23:21:06.765882 [ 7.575470] sp : c3451c70 ip : 2d827000 fp : c1804c48 23:21:06.766053 [ 7.580680] r10: 00000000 r9 : ec9cc300 r8 : 00000000 23:21:06.766229 [ 7.585893] r7 : bf193c80 r6 : 00000000 r5 : c3694224 r4 : fffffffc 23:21:06.766403 [ 7.592404] r3 : 00002000 r2 : 0002f000 r1 : eef92cf0 r0 : c3694000 ... 23:21:07.068237 [ 7.880215] [<c09a8700>] (drm_plane_register_all) from [<c09ab240>] (drm_modeset_register_all+0xc/0x6c) 23:21:07.068493 [ 7.889603] [<c09ab240>] (drm_modeset_register_all) from [<c0992054>] (drm_dev_register+0x16c/0x1c4) 23:21:07.109960 [ 7.898915] [<c0992054>] (drm_dev_register) from [<bf0ec0d8>] (nouveau_platform_probe+0x54/0x8c [nouveau]) 23:21:07.110285 [ 7.908750] [<bf0ec0d8>] (nouveau_platform_probe [nouveau]) from [<c0a45968>] (platform_drv_probe+0x48/0x98) 23:21:07.110515 [ 7.918572] [<c0a45968>] (platform_drv_probe) from [<c0a43bd8>] (really_probe+0x228/0x2d0) 23:21:07.110706 [ 7.926832] [<c0a43bd8>] (really_probe) from [<c0a43de4>] (driver_probe_device+0x60/0x174) 23:21:07.110893 [ 7.935093] [<c0a43de4>] (driver_probe_device) from [<c0a43fc8>] (__driver_attach+0xd0/0xd4) 23:21:07.153794 [ 7.943528] [<c0a43fc8>] (__driver_attach) from [<c0a41e8c>] (bus_for_each_dev+0x74/0xb4) 23:21:07.154133 [ 7.951688] [<c0a41e8c>] (bus_for_each_dev) from [<c0a42ff0>] (bus_add_driver+0x18c/0x210) 23:21:07.154352 [ 7.959946] [<c0a42ff0>] (bus_add_driver) from [<c0a44b24>] (driver_register+0x74/0x108) 23:21:07.154544 [ 7.968212] [<c0a44b24>] (driver_register) from [<bf1bb170>] (nouveau_drm_init+0x170/0x1000 [nouveau]) 23:21:07.154739 [ 7.977692] [<bf1bb170>] (nouveau_drm_init [nouveau]) from [<c0402d6c>] (do_one_initcall+0x54/0x1fc) 23:21:07.197008 [ 7.986820] [<c0402d6c>] (do_one_initcall) from [<c04d276c>] (do_init_module+0x64/0x1f4) 23:21:07.197344 [ 7.994906] [<c04d276c>] (do_init_module) from [<c04d1980>] (load_module+0x1ee8/0x23c8) 23:21:07.197553 [ 8.002907] [<c04d1980>] (load_module) from [<c04d2080>] (sys_finit_module+0xac/0xd8) 23:21:07.197751 [ 8.010722] [<c04d2080>] (sys_finit_module) from [<c0401000>] (ret_fast_syscall+0x0/0x4c) 23:21:07.197935 [ 8.018884] Exception stack(0xc3451fa8 to 0xc3451ff0) Both PC and LR are pointing to drm_* code. I don't see this anyway related to uprobes. Did I miss anything? Thanks, Ravi On 12/7/18 9:30 AM, kernelci.org bot wrote: > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > * This automated bisection report was sent to you on the basis * > * that you may be involved with the breaking commit it has * > * found. No manual investigation has been done to verify it, * > * and the root cause of the problem may be somewhere else. * > * Hope this helps! * > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > > Bisection result for mainline/master (v4.20-rc5-79-gabb8d6ecbd8f) on > jetson-tk1 > > Good: cf76c364a1e1 Merge tag 'scsi-fixes' of > git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi > Bad: abb8d6ecbd8f Merge tag 'trace-v4.20-rc5' of > git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace > Found: 1aed58e67a6e Uprobes: Fix kernel oops with > delayed_uprobe_remove() > > Details: > Good: > https://kernelci.org/boot/all/job/mainline/branch/master/kernel/v4.20-rc5-62-gcf76c364a1e1/ > Bad: > https://kernelci.org/boot/all/job/mainline/branch/master/kernel/v4.20-rc5-79-gabb8d6ecbd8f/ > > Checks: > revert: PASS > verify: PASS > > Parameters: > Tree: mainline > URL: > http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > Branch: master > Target: jetson-tk1 > Lab: lab-baylibre > Config: multi_v7_defconfig > Plan: boot > > Breaking commit found: > > ------------------------------------------------------------------------------- > commit 1aed58e67a6ec1e7a18bfabe8ba6ec2d27c15636 > Author: Ravi Bangoria <ravi.bango...@linux.ibm.com> > Date: Wed Dec 5 09:04:23 2018 +0530 > > Uprobes: Fix kernel oops with delayed_uprobe_remove() > > There could be a race between task exit and probe unregister: > > exit_mm() > mmput() > __mmput() uprobe_unregister() > uprobe_clear_state() put_uprobe() > delayed_uprobe_remove() delayed_uprobe_remove() > > put_uprobe() is calling delayed_uprobe_remove() without taking > delayed_uprobe_lock and thus the race sometimes results in a > kernel crash. Fix this by taking delayed_uprobe_lock before > calling delayed_uprobe_remove() from put_uprobe(). > > Detailed crash log can be found at: > Link: http://lkml.kernel.org/r/000000000000140c370577db5...@google.com > > Link: > http://lkml.kernel.org/r/20181205033423.26242-1-ravi.bango...@linux.ibm.com > > Acked-by: Oleg Nesterov <o...@redhat.com> > Reviewed-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com> > Reported-by: syzbot+cb1fb754b771caca0...@syzkaller.appspotmail.com > Fixes: 1cc33161a83d ("uprobes: Support SDT markers having reference count > (semaphore)") > Signed-off-by: Ravi Bangoria <ravi.bango...@linux.ibm.com> > Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org> > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index 96d4bee83489..98b9312ce6b2 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -572,7 +572,9 @@ static void put_uprobe(struct uprobe *uprobe) > * gets called, we don't get a chance to remove uprobe from > * delayed_uprobe_list from remove_breakpoint(). Do it here. > */ > + mutex_lock(&delayed_uprobe_lock); > delayed_uprobe_remove(uprobe, NULL); > + mutex_unlock(&delayed_uprobe_lock); > kfree(uprobe); > } > } > ------------------------------------------------------------------------------- > > > Git bisection log: > > ------------------------------------------------------------------------------- > git bisect start > # good: [cf76c364a1e1e5224af80edf70a1e3023e1fcf8c] Merge tag 'scsi-fixes' of > git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi > git bisect good cf76c364a1e1e5224af80edf70a1e3023e1fcf8c > # bad: [abb8d6ecbd8f7801c048f6543f79d22d24cead7b] Merge tag 'trace-v4.20-rc5' > of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace > git bisect bad abb8d6ecbd8f7801c048f6543f79d22d24cead7b > # good: [33aaebd48ae2d2c78fef5063a0381e17db19b060] ALSA: hda/realtek: ALC286 > mic and headset-mode fixups for Acer Aspire U27-880 > git bisect good 33aaebd48ae2d2c78fef5063a0381e17db19b060 > # good: [b72f936f6b325f4fde06b02e4b6ab682f6f2e73f] ALSA: hda/realtek: Fix mic > issue on Acer AIO Veriton Z4860G/Z6860G > git bisect good b72f936f6b325f4fde06b02e4b6ab682f6f2e73f > # good: [002f421a84c5a9260bf0e312af5d5043b3555511] Merge tag 'csky-4.20-rc6' > of github.com:c-sky/csky-linux > git bisect good 002f421a84c5a9260bf0e312af5d5043b3555511 > # bad: [1aed58e67a6ec1e7a18bfabe8ba6ec2d27c15636] Uprobes: Fix kernel oops > with delayed_uprobe_remove() > git bisect bad 1aed58e67a6ec1e7a18bfabe8ba6ec2d27c15636 > # first bad commit: [1aed58e67a6ec1e7a18bfabe8ba6ec2d27c15636] Uprobes: Fix > kernel oops with delayed_uprobe_remove() > ------------------------------------------------------------------------------- >
