Re: [PATCH] mm: nommu: per-thread vma cache fix

From: Davidlohr Bueso
Date: Thu Jun 12 2014 - 14:04:52 EST

On Tue, 2014-06-10 at 18:28 +0800, Steven Miao (Steven Miao) wrote:
> From: Steven Miao <realmz6@xxxxxxxxx>
>
> mm could be removed from current task struct, using previous vma->vm_mm
>
> It will crash on blackfin after updated to Linux 3.15. The commit "mm: per-thread vma caching" caused the crash.
> mm could be removed from current task struct before
> mmput()->
> exit_mmap()->
> delete_vma_from_mm()
>
> the detailed booting log:
>
> ## Booting kernel from Legacy Image at 01000000 ...
> Image Name: bf609-0.0-3.15.0-ADI-2014R1-pre-
> Image Type: Blackfin Linux Kernel Image (gzip compressed)
> Data Size: 10293222 Bytes = 9.8 MiB
> Load Address: 00001000
> Entry Point: 002e796c
> Verifying Checksum ... OK
> Uncompressing Kernel Image ... OK
> Starting Kernel at = 002e796c
> Linux version 3.15.0-ADI-2014R1-pre-00345-gea9f446 (steven@steven-OptiPlex-390) (gcc version 4.3.5 (ADI-trunk/svn-5962) ) #25 Tue Jun 10 17:47:46 CST 2014
> register early platform devices
> bootconsole [early_shadow0] enabled
> ERROR: Not running on ADSP-BF609: unknown CPUID 0x0000 Rev 0.0
> bootconsole [early_BFuart0] enabled
> early printk enabled on early_BFuart0
> Board Memory: 128MB
> Kernel Managed Memory: 128MB
> Memory map:
> fixedcode = 0x00000400-0x00000490
> text = 0x00001000-0x001fa910
> rodata = 0x001fa934-0x002a1ea8
> bss = 0x002a2000-0x002b9bc0
> data = 0x002b9bc0-0x002e4000
> stack = 0x002e2000-0x002e4000
> init = 0x002e4000-0x00b45000
> available = 0x00b45000-0x07f00000
> DMA Zone = 0x07f00000-0x08000000
> Hardware Trace active and enabled
> Blackfin support (C) 2004-2010 Analog Devices, Inc.
> Compiled for ADSP-BF609 Rev 0.0
> Blackfin Linux support by http://blackfin.uclinux.org/
> Processor Speed: 500 MHz core clock, 125 MHz SCLk, 125 MHz SCLK0, 125 MHz SCLK1 and 250 MHz DCLK
> NOMPU: setting up cplb tables
> Instruction Cache Enabled for CPU0
> External memory: cacheable in instruction cache
> L2 SRAM : uncacheable in instruction cache
> Data Cache Enabled for CPU0
> External memory: cacheable (write-back) in data cache
> L2 SRAM : uncacheable in data cache
> Built 1 zonelists in Zone order, mobility grouping off. Total pages: 32258
> Kernel command line: root=/dev/mtdblock0 rw clkin_hz=(25000000) earlyprintk=serial,uart0,57600 console=ttyBF0,57600 ip=10.99.24.159:10.99.24.86:10.99.24.1:255.255.255.0:"bf609-ezkit":eth0:off
> PID hash table entries: 512 (order: -1, 2048 bytes)
> Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)
> Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)
> Memory: 117340K/130048K available (2022K kernel code, 169K rwdata, 669K rodata, 8580K init, 94K bss, 12708K reserved, 1024K DMA)
> NR_IRQS:291
> Configuring Blackfin Priority Driven Interrupts
> Console: colour dummy device 80x25
> Calibrating delay loop... 995.32 BogoMIPS (lpj=1990656)
> pid_max: default: 32768 minimum: 301
> Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
> Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
> devtmpfs: initialized
> Blackfin Scratchpad data SRAM: 4 KB
> Blackfin L1 Data A SRAM: 16 KB (9 KB free)
> Blackfin L1 Data B SRAM: 16 KB (16 KB free)
> Blackfin L1 Instruction SRAM: 64 KB (49 KB free)
> Blackfin L2 SRAM: 256 KB (256 KB free)
> pinctrl core: initialized pinctrl subsystem
> NET: Registered protocol family 16
> Blackfin DMA Controller
> ezkit_init(): registering device resources
> SCSI subsystem initialized
> usbcore: registered new interface driver usbfs
> usbcore: registered new interface driver hub
> usbcore: registered new device driver usb
> i2c-bfin-twi i2c-bfin-twi.0: Blackfin on-chip I2C TWI Contoller, regs_base@ffc01e00
> i2c-bfin-twi i2c-bfin-twi.1: Blackfin on-chip I2C TWI Contoller, regs_base@ffc01f00
> pps_core: LinuxPPS API ver. 1 registered
> pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@xxxxxxxx>
> PTP clock support registered
> NET: Registered protocol family 23
> Switched to clocksource bfin_cs_cycles
> NET: Registered protocol family 2
> TCP established hash table entries: 1024 (order: 0, 4096 bytes)
> TCP bind hash table entries: 1024 (order: 0, 4096 bytes)
> TCP: Hash tables configured (established 1024 bind 1024)
> TCP: reno registered
> UDP hash table entries: 256 (order: 0, 4096 bytes)
> UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
> NET: Registered protocol family 1
> msgmni has been set to 229
> io scheduler noop registered (default)
> bfin-uart: Blackfin serial driver
> bfin-uart.0: ttyBF0 at MMIO 0xffc02000 (irq = 88, base_baud = 7812500) is a BFIN-UART
> console [ttyBF0] enabled
> console [ttyBF0] enabled
> bootconsole [early_BFuart0] disabled
> bootconsole [early_BFuart0] disabled
> bootconsole [early_shadow0] disabled
> CAN device driver interface
> bfin_can bfin_can.0: bfin_can device registered(&reg_base=ffc00a00, rx_irq=47, tx_irq=48, err_irq=49, sclk=125000000)
> stmmaceth stmmaceth.0: no reset control found
> stmmac - user ID: 0x10, Synopsys ID: 0x36
> Ring mode enabled
> DMA HW capability register supported
> Enhanced/Alternate descriptors
> Enabled extended descriptors
> RX Checksum Offload Engine supported (type 2)
> Wake-Up On Lan supported
> Enable RX Mitigation via HW Watchdog Timer
> NULL pointer access
> Kernel OOPS in progress
> Deferred Exception context
> CURRENT PROCESS:
> COMM=modprobe PID=278 CPU=0
> invalid mm
> return address: [0x000531de]; contents of:
> 0x000531b0: c727 acea 0c42 181d 0000 0000 0000 a0a8
> 0x000531c0: b090 acaa 0c42 1806 0000 0000 0000 a0e8
> 0x000531d0: b0d0 e801 0000 05b3 0010 e522 0046 [a090]
> 0x000531e0: 6408 b090 0c00 17cc 3042 e3ff f37b 2fc8
>
> CPU: 0 PID: 278 Comm: modprobe Not tainted 3.15.0-ADI-2014R1-pre-00345-gea9f446 #25
> task: 0572b720 ti: 0569e000 task.ti: 0569e000
> Compiled for cpu family 0x27fe (Rev 0), but running on:0x0000 (Rev 0)
> ADSP-BF609-0.0 500(MHz CCLK) 125(MHz SCLK) (mpu off)
> Linux version 3.15.0-ADI-2014R1-pre-00345-gea9f446 (steven@steven-OptiPlex-390) (gcc version 4.3.5 (ADI-trunk/svn-5962) ) #25 Tue Jun 10 17:47:46 CST 2014
>
> SEQUENCER STATUS: Not tainted
> SEQSTAT: 00000027 IPEND: 8008 IMASK: ffff SYSCFG: 2806
> EXCAUSE : 0x27
> physical IVG3 asserted : <0xffa00744> { _trap + 0x0 }
> physical IVG15 asserted : <0xffa00d68> { _evt_system_call + 0x0 }
> logical irq 6 mapped : <0xffa003bc> { _bfin_coretmr_interrupt + 0x0 }
> logical irq 7 mapped : <0x00008828> { _bfin_fault_routine + 0x0 }
> logical irq 11 mapped : <0x00007724> { _l2_ecc_err + 0x0 }
> logical irq 13 mapped : <0x00008828> { _bfin_fault_routine + 0x0 }
> logical irq 39 mapped : <0x00150788> { _bfin_twi_interrupt_entry + 0x0 }
> logical irq 40 mapped : <0x00150788> { _bfin_twi_interrupt_entry + 0x0 }
> RETE: <0x00000000> /* Maybe null pointer? */
> RETN: <0x0569fe50> /* kernel dynamic memory (maybe user-space) */
> RETX: <0x00000480> /* Maybe fixed code section */
> RETS: <0x00053384> { _exit_mmap + 0x28 }
> PC : <0x000531de> { _delete_vma_from_mm + 0x92 }
> DCPLB_FAULT_ADDR: <0x00000008> /* Maybe null pointer? */
> ICPLB_FAULT_ADDR: <0x000531de> { _delete_vma_from_mm + 0x92 }
> PROCESSOR STATE:
> R0 : 00000004 R1 : 0569e000 R2 : 00bf3db4 R3 : 00000000
> R4 : 057f9800 R5 : 00000001 R6 : 0569ddd0 R7 : 0572b720
> P0 : 0572b854 P1 : 00000004 P2 : 00000000 P3 : 0569dda0
> P4 : 0572b720 P5 : 0566c368 FP : 0569fe5c SP : 0569fd74
> LB0: 057f523f LT0: 057f523e LC0: 00000000
> LB1: 0005317c LT1: 00053172 LC1: 00000002
> B0 : 00000000 L0 : 00000000 M0 : 0566f5bc I0 : 00000000
> B1 : 00000000 L1 : 00000000 M1 : 00000000 I1 : ffffffff
> B2 : 00000001 L2 : 00000000 M2 : 00000000 I2 : 00000000
> B3 : 00000000 L3 : 00000000 M3 : 00000000 I3 : 057f8000
> A0.w: 00000000 A0.x: 00000000 A1.w: 00000000 A1.x: 00000000
> USP : 056ffcf8 ASTAT: 02003024
>
> Hardware Trace:
> 0 Target : <0x00003fb8> { _trap_c + 0x0 }
> Source : <0xffa006d8> { _exception_to_level5 + 0xa0 } JUMP.L
> 1 Target : <0xffa00638> { _exception_to_level5 + 0x0 }
> Source : <0xffa004f2> { _bfin_return_from_exception + 0x6 } RTX
> 2 Target : <0xffa004ec> { _bfin_return_from_exception + 0x0 }
> Source : <0xffa00590> { _ex_trap_c + 0x70 } JUMP.S
> 3 Target : <0xffa00520> { _ex_trap_c + 0x0 }
> Source : <0xffa0076e> { _trap + 0x2a } JUMP (P4)
> 4 Target : <0xffa00744> { _trap + 0x0 }
> FAULT : <0x000531de> { _delete_vma_from_mm + 0x92 } P0 = W[P2 + 2]
> Source : <0x000531da> { _delete_vma_from_mm + 0x8e } P2 = [P4 + 0x18]
> 5 Target : <0x000531da> { _delete_vma_from_mm + 0x8e }
> Source : <0x00053176> { _delete_vma_from_mm + 0x2a } IF CC JUMP pcrel
> 6 Target : <0x0005314c> { _delete_vma_from_mm + 0x0 }
> Source : <0x00053380> { _exit_mmap + 0x24 } JUMP.L
> 7 Target : <0x00053378> { _exit_mmap + 0x1c }
> Source : <0x00053394> { _exit_mmap + 0x38 } IF !CC JUMP pcrel (BP)
> 8 Target : <0x00053390> { _exit_mmap + 0x34 }
> Source : <0xffa020e0> { __cond_resched + 0x20 } RTS
> 9 Target : <0xffa020c0> { __cond_resched + 0x0 }
> Source : <0x0005338c> { _exit_mmap + 0x30 } JUMP.L
> 10 Target : <0x0005338c> { _exit_mmap + 0x30 }
> Source : <0x0005333a> { _delete_vma + 0xb2 } RTS
> 11 Target : <0x00053334> { _delete_vma + 0xac }
> Source : <0x0005507a> { _kmem_cache_free + 0xba } RTS
> 12 Target : <0x00055068> { _kmem_cache_free + 0xa8 }
> Source : <0x0005505e> { _kmem_cache_free + 0x9e } IF !CC JUMP pcrel (BP)
> 13 Target : <0x00055052> { _kmem_cache_free + 0x92 }
> Source : <0x0005501a> { _kmem_cache_free + 0x5a } IF CC JUMP pcrel
> 14 Target : <0x00054ff4> { _kmem_cache_free + 0x34 }
> Source : <0x00054fce> { _kmem_cache_free + 0xe } IF CC JUMP pcrel (BP)
> 15 Target : <0x00054fc0> { _kmem_cache_free + 0x0 }
> Source : <0x00053330> { _delete_vma + 0xa8 } JUMP.L
> Kernel Stack
> Stack info:
> SP: [0x0569ff24] <0x0569ff24> /* kernel dynamic memory (maybe user-space) */
> Memory from 0x0569ff20 to 056a0000
> 0569ff20: 00000001 [04e8da5a] 00008000 00000000 00000000 056a0000 04e8da5a 04e8da5a
> 0569ff40: 04eb9eea ffa00dce 02003025 04ea09c5 057f523f 04ea09c4 057f523e 00000000
> 0569ff60: 00000000 00000000 00000000 00000000 00000000 00000000 00000001 00000000
> 0569ff80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 0569ffa0: 0566f5bc 057f8000 057f8000 00000001 04ec0170 056ffcf8 056ffd04 057f9800
> 0569ffc0: 04d1d498 057f9800 057f8fe4 057f8ef0 00000001 057f928c 00000001 00000001
> 0569ffe0: 057f9800 00000000 00000008 00000007 00000001 00000001 00000001 <00002806>
> Return addresses in stack:
> address : <0x00002806> { _show_cpuinfo + 0x2d2 }
> Modules linked in:
> Kernel panic - not syncing: Kernel exception
> ---[ end Kernel panic - not syncing: Kernel exception
>
>
> Signed-off-by: Steven Miao <realmz6@xxxxxxxxx>

Acked-by: Davidlohr Bueso <davidlohr@xxxxxx>

Sorry for the late reply. I'm glad we're getting the vmacache tested on
nommu systems -- something I hadn't been able to do.

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