Re: mainline/master boot bisection: v4.20-rc5-79-gabb8d6ecbd8f on jetson-tk1
From: Ravi Bangoria
Date: Mon Dec 10 2018 - 05:53:02 EST
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.bangoria@xxxxxxxxxxxxx>
> 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/000000000000140c370577db5ece@xxxxxxxxxx
>
> Link: http://lkml.kernel.org/r/20181205033423.26242-1-ravi.bangoria@xxxxxxxxxxxxx
>
> Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
> Reviewed-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
> Reported-by: syzbot+cb1fb754b771caca0a88@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 1cc33161a83d ("uprobes: Support SDT markers having reference count (semaphore)")
> Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
>
> 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()
> -------------------------------------------------------------------------------
>