Re: linux-next: boot failure after merge of the iomem-mmap-vs-gup tree

[Stephen Rothwell]

Hi all,

On Wed, 13 Jan 2021 16:29:48 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> 
> After merging the iomem-mmap-vs-gup tree, today's linux-next boot test
> (powerpc pseries_le_defconfig) failed like this:
> 
>     EEH: pSeries platform initialized
>     PCI: Probing PCI hardware
>     BUG: Kernel NULL pointer dereference on write at 0x00000030
>     Faulting instruction address: 0xc00000000013bf4c
>     Oops: Kernel access of bad area, sig: 11 [#1]
>     LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
>     Modules linked in:
>     CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.11.0-rc3 #2
>     NIP:  c00000000013bf4c LR: c0000000007a9ee8 CTR: 0000000000000000
>     REGS: c0000000063a3610 TRAP: 0380   Not tainted  (5.11.0-rc3)
>     MSR:  8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 84002440  XER: 00000000
>     CFAR: c0000000007a9ee4 IRQMASK: 0 
>     GPR00: c0000000007a9ee8 c0000000063a38b0 c0000000013d8100 c000000006061300 
>     GPR04: 0000000000000000 0000000000000b20 c000000000f11738 000000000000ffff 
>     GPR08: c0000000007a7ab0 0000000000000000 c0000000007a7a40 2d6770696f730000 
>     GPR12: 0000000000000000 c0000000015b0000 c000000000013120 0000000000000000 
>     GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
>     GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 
>     GPR24: c000000006210de8 c000000006167120 c000000006620b20 0000000000000000 
>     GPR28: c000000006167120 0000000000000180 c000000006061300 c000000006167000 
>     NIP [c00000000013bf4c] iomem_get_mapping+0x1c/0x30
>     LR [c0000000007a9ee8] pci_create_legacy_files+0xa8/0x1c0
>     Call Trace:
>     [c0000000063a38b0] [c0000000007a9e84] pci_create_legacy_files+0x44/0x1c0 (unreliable)
>     [c0000000063a3930] [c000000000795198] pci_register_host_bridge+0x288/0x510
>     [c0000000063a3a60] [c000000000795514] pci_create_root_bus+0xf4/0x150
>     [c0000000063a3ac0] [c00000000006d424] pcibios_scan_phb+0xe4/0x270
>     [c0000000063a3b70] [c000000001010b40] pcibios_init+0x8c/0x128
>     [c0000000063a3bf0] [c000000000012b70] do_one_initcall+0x60/0x2c0
>     [c0000000063a3cc0] [c0000000010046b4] kernel_init_freeable+0x2e8/0x380
>     [c0000000063a3da0] [c000000000013144] kernel_init+0x2c/0x168
>     [c0000000063a3e10] [c00000000000dff0] ret_from_kernel_thread+0x5c/0x6c
>     Instruction dump:
>     7c634850 4e800020 60000000 60000000 60420000 3c4c012a 3842c1d0 7c0802a6 
>     60000000 3d22000d e929caf8 7c2004ac <e8690030> 4e800020 60000000 60000000 
>     ---[ end trace 77f55ece72f02708 ]---
>     
>     Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
> 
> Caused by commit
> 
>   85482fbab59e ("PCI: Revoke mappings like devmem")
> 
> Reverting that commit fixes the boot, so I have done that for today.

I am still reverting this commit.

-- 
Cheers,
Stephen Rothwell

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