ARM64: Regression with commit e3067861ba66 ("arm64: add basic VMAP_STACK support")

[Mark Rutland]

On Tue, Oct 10, 2017 at 10:27:25PM +0800, Leo Yan wrote:
> Hi Mark,

Hi Leo,
 
> I work mainline kernel on Hikey620 board, I find it's easily to
> introduce the panic and report the log as below. So I bisect the kernel
> and finally narrow down the commit e3067861ba66 ("arm64: add basic
> VMAP_STACK support") which introduce this issue.
> 
> I tried to remove 'select HAVE_ARCH_VMAP_STACK' from
> arch/arm64/Kconfig, then I can see the panic issue will dismiss. So
> could you check this and have insight for this issue?

Given the stuff in the backtrace, my suspicion is something is trying to
perform DMA to/from the stack, getting junk addresses form the attempted
virt<->phys conversions.

Could you try enabling both VMAP_STACK and CONFIG_DEBUG_VIRTUAL?

Thanks,
Mark.

> [   42.384103] INFO: rcu_preempt detected stalls on CPUs/tasks:
> [   42.389799]  5-...: (1 GPs behind) idle=252/140000000000000/0 softirq=1208/1236 fqs=2615 
> [   42.397982]  (detected by 0, t=5255 jiffies, g=238, c=237, q=10)
> [   42.403999] Task dump for CPU 5:
> [   42.407225] bash            R  running task        0  2202   2176 0x00000002
> [   42.414281] Call trace:
> [   42.416738] [<ffff0000080842a0>] ret_from_fork+0x0/0x18
> [   43.308258] Unable to handle kernel paging request at virtual address 80083517baba
> [   43.315864] user pgtable: 4k pages, 48-bit VAs, pgd = ffff80003a629000
> [   43.322429] [000080083517baba] *pgd=0000000000000000
> [   43.327419] Internal error: Oops: 96000004 [#1] PREEMPT SMP
> [   43.332994] Modules linked in:
> [   43.336053] CPU: 1 PID: 54 Comm: kworker/u16:2 Not tainted 4.13.0-rc3-00019-ge306786 #199
> [   43.344235] Hardware name: HiKey Development Board (DT)
> [   43.349472] Workqueue: writeback wb_workfn (flush-179:0)
> [   43.354789] task: ffff80003be71e80 task.stack: ffff0000093a0000
> [   43.360723] PC is at __kmalloc+0x64/0x250
> [   43.364739] LR is at __kmalloc+0x30/0x250
> [   43.368754] pc : [<ffff0000081dccc4>] lr : [<ffff0000081dcc90>] pstate: 40000145
> [   43.376165] sp : ffff0000093a34f0
> [   43.379484] x29: ffff0000093a34f0 x28: ffff80003aaaa228 
> [   43.384806] x27: 0000000000000000 x26: ffff80003be71e80 
> [   43.390128] x25: ffff80003be71e80 x24: 0000000000400000 
> [   43.395450] x23: ffff80003be71e80 x22: ffff0000087c6458 
> [   43.400772] x21: 0000000001011200 x20: ffff80003aff0080 
> [   43.406093] x19: ffff800005f04a80 x18: 000000000000000e 
> [   43.411415] x17: 0000ffffa714438c x16: ffff000008244400 
> [   43.416737] x15: 000011bb63554e12 x14: 0000000a155ddaef 
> [   43.422059] x13: 00000000000fffff x12: 0000000000000040 
> [   43.427381] x11: ffff7e0000f1bbc0 x10: 0000000000000001 
> [   43.432707] x9 : 0000000000000000 x8 : 0000000000000019 
> [   43.438035] x7 : ffff7e0000ec8020 x6 : 0000000000000040 
> [   43.443363] x5 : 0000000000000000 x4 : 0000000000000001 
> [   43.448691] x3 : 07ffffffffffffff x2 : ffff800005f04a80 
> [   43.454020] x1 : 000080003504f000 x0 : 000000080012caba 
> [   43.459350] Process kworker/u16:2 (pid: 54, stack limit = 0xffff0000093a0000)
> [   43.466501] Call trace:
> [   43.468958] Exception stack(0xffff0000093a33b0 to 0xffff0000093a34f0)
> [   43.475415] 33a0:                                   000000080012caba 000080003504f000
> [   43.483273] 33c0: ffff800005f04a80 07ffffffffffffff 0000000000000001 0000000000000000
> [   43.491131] 33e0: 0000000000000040 ffff7e0000ec8020 0000000000000019 0000000000000000
> [   43.498989] 3400: 0000000000000001 ffff7e0000f1bbc0 0000000000000040 00000000000fffff
> [   43.506847] 3420: 0000000a155ddaef 000011bb63554e12 ffff000008244400 0000ffffa714438c
> [   43.514705] 3440: 000000000000000e ffff800005f04a80 ffff80003aff0080 0000000001011200
> [   43.522563] 3460: ffff0000087c6458 ffff80003be71e80 0000000000400000 ffff80003be71e80
> [   43.530421] 3480: ffff80003be71e80 0000000000000000 ffff80003aaaa228 ffff0000093a34f0
> [   43.538279] 34a0: ffff0000081dcc90 ffff0000093a34f0 ffff0000081dccc4 0000000040000145
> [   43.546129] 34c0: 00000000ffffffff 0000000000000001 ffffffffffffffff 0000000000000000
> [   43.553976] 34e0: ffff0000093a34f0 ffff0000081dccc4
> [   43.558862] [<ffff0000081dccc4>] __kmalloc+0x64/0x250
> [   43.563926] [<ffff0000087c6458>] mmc_alloc_sg+0x28/0x60
> [   43.569162] [<ffff0000087c653c>] mmc_init_request+0xac/0xc0
> [   43.574747] [<ffff000008378af4>] alloc_request_size+0x4c/0x90
> [   43.580506] [<ffff00000817c734>] mempool_alloc+0x54/0x140
> [   43.585915] [<ffff000008379d7c>] get_request+0x264/0x6d0
> [   43.591238] [<ffff00000837ce50>] blk_queue_bio+0xe0/0x2e0
> [   43.596647] [<ffff00000837acc8>] generic_make_request+0xe8/0x260
> [   43.602663] [<ffff00000837aef0>] submit_bio+0xb0/0x188
> [   43.607812] [<ffff0000082330f0>] submit_bh_wbc+0x130/0x188
> [   43.613308] [<ffff0000082332e0>] __block_write_full_page+0x198/0x3a0
> [   43.619673] [<ffff00000823374c>] block_write_full_page+0x134/0x148
> [   43.625866] [<ffff000008236b20>] blkdev_writepage+0x18/0x20
> [   43.631448] [<ffff00000818596c>] __writepage+0x1c/0x70
> [   43.636595] [<ffff0000081861d8>] write_cache_pages+0x160/0x360
> [   43.642438] [<ffff000008186418>] generic_writepages+0x40/0x78
> [   43.648194] [<ffff000008236adc>] blkdev_writepages+0xc/0x18
> [   43.653783] [<ffff00000818853c>] do_writepages+0x2c/0xa8
> [   43.659113] [<ffff00000822986c>] __writeback_single_inode+0x34/0x1a8
> [   43.665486] [<ffff000008229f34>] writeback_sb_inodes+0x1ec/0x398
> [   43.671510] [<ffff00000822a17c>] __writeback_inodes_wb+0x9c/0xe0
> [   43.677534] [<ffff00000822a418>] wb_writeback+0x1a8/0x1b0
> [   43.682950] [<ffff00000822a9d8>] wb_workfn+0x148/0x240
> [   43.688105] [<ffff0000080d93f4>] process_one_work+0x1ac/0x318
> [   43.693867] [<ffff0000080d95a8>] worker_thread+0x48/0x420
> [   43.699283] [<ffff0000080df664>] kthread+0xfc/0x128
> [   43.704178] [<ffff0000080842b0>] ret_from_fork+0x10/0x18
> [   43.709506] Code: b90012e0 f9400260 d538d081 91002000 (f8616818) 
> [   43.715617] ---[ end trace 9381b75685031f84 ]---
> [   43.720290] note: kworker/u16:2[54] exited with preempt_count 1
>