On Thu, 6 Sep 2018 at 09:10, Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote: > > Hi, > > Today's next fails to mount NFS root under my ARM targets and fails to > mount root from file image under QMU. > > [ 21.512866] Unable to handle kernel NULL pointer dereference at > virtual address 00000000 > [ 21.695484] [<c03bcc04>] (nfs_fs_mount) from [<c02cf6a4>] > (legacy_get_tree+0x34/0xec) > [ 21.703225] [<c02cf6a4>] (legacy_get_tree) from [<c029442c>] > (vfs_get_tree+0x64/0x180) > [ 21.711119] [<c029442c>] (vfs_get_tree) from [<c02b9140>] > (do_mount+0x21c/0x958) > [ 21.718478] [<c02b9140>] (do_mount) from [<c02b9c38>] (ksys_mount+0x8c/0xbc) > [ 21.725513] [<c02b9c38>] (ksys_mount) from [<c0101000>] > (ret_fast_syscall+0x0/0x28) > > Full log from ARM (NFS root): > https://krzk.eu/#/builders/25/builds/750/steps/12/logs/serial0 > > The NFS root failure bisected to: > bae551929c5433bd56ec4dcb97c7d4a50153d357 is the first bad commit > commit bae551929c5433bd56ec4dcb97c7d4a50153d357 > Author: David Howells <dhowells@xxxxxxxxxx> > Date: Tue Jul 10 21:43:37 2018 +0100 FYI, the bug is still present in linux-next. All boards fail to boot up. Let me know if I can help anymore in debugging this. Best regards, Krzysztof > > vfs: Separate changing mount flags full remount > > Separate just the changing of mount flags (MS_REMOUNT|MS_BIND) from full > remount because the mount data will get parsed with the new fs_context > stuff prior to doing a remount - and this causes the syscall to fail under > some circumstances. > > The QEMU issue seems slightly different and I did not bisect it. The > QEMU just cannot find rootfs: > [ 1.008052] Filesystem requires source device > [ 1.008513] VFS: Cannot open root device "mmcblk0" or > unknown-block(179,0): error -2 > [ 1.008790] Please append a correct "root=" boot option; here are > the available partitions: > [ 1.009300] 0100 16384 ram0 > [ 1.009337] (driver?) > [ 1.009806] fe00 5120 vda > [ 1.009843] driver: virtio_blk > [ 1.010296] b300 110592 mmcblk0 > [ 1.010319] driver: mmcblk > [ 1.010859] Kernel panic - not syncing: VFS: Unable to mount root > fs on unknown-block(179,0) > [ 1.011580] ---[ end Kernel panic - not syncing: VFS: Unable to > mount root fs on unknown-block(179,0) ]--- > > > > Boards config: > 1. Arch ARM Linux > 2. exynos_defconfig > - Odroid HC1 > ARMv7, octa-core (Cortex-A7+A15), Exynos5422 SoC > Systemd: v239 > - Odroid U3 > ARMv7, quad-core, Exynos4412 SoC > Systemd: v238 > - Odroid XU > ARMv7, octa-core (Cortex-A7+A15) but only A15 working, Exynos5410 SoC > Systemd: v236 > - Odroid XU3 > ARMv7, octa-core (Cortex-A7+A15), Exynos5422 SoC > Systemd: v236 > 3. Custom VF50 defconfig > - Toradex Colibri VF50 on Iris board > ARMv7, UP, Cortext-A5, NXP VF500 > Systemd: v232 > 4. All boards boot from TFTP with NFS root (NFSv4) > 5. QEMU > ARMv7, vexpress-v2p-ca9, 128 MB RAM > > > > Best regards, > Krzysztof
