[#3898] showing processsor state via magic sysrq crashes the kernel

Submitted By: Mike Frysinger

Open Date

2008-02-14 21:51:32 Close Date

2008-03-17 19:20:43

Priority:

Medium Assignee:

Robin Getz

Status:

Closed Fixed In Release:

N/A

Found In Release:

N/A Release:

linux-2.6.24.2

Category:

N/A Board:

N/A

Processor:

N/A Silicon Revision:

Is this bug repeatable?:

Yes Resolution:

Fixed

Uboot version or rev.:

Toolchain version or rev.:

App binary format:

N/A

Summary: showing processsor state via magic sysrq crashes the kernel

Details:

with current trunk, enabling magic sysrq and then trying to show the pc (break+p) will crash the kernel:

root:/> SysRq : Show Regs

SEQUENCER STATUS: Not tainted

SEQSTAT: 00002000 IPEND: ffff SYSCFG: 0006

HWERRCAUSE: 0x0

EXCAUSE : 0x0

physical IVG6 asserted : <0xffa00df4> { _evt_timer + 0x0 }

physical IVG7 asserted : <0xffa00e0c> { _evt_evt7 + 0x0 }

physical IVG8 asserted : <0xffa00e18> { _evt_evt8 + 0x0 }

physical IVG9 asserted : <0xffa00e24> { _evt_evt9 + 0x0 }

physical IVG10 asserted : <0xffa00e30> { _evt_evt10 + 0x0 }

physical IVG11 asserted : <0xffa00e3c> { _evt_evt11 + 0x0 }

physical IVG12 asserted : <0xffa00e48> { _evt_evt12 + 0x0 }

physical IVG13 asserted : <0xffa00e54> { _evt_evt13 + 0x0 }

physical IVG14 asserted : <0xffa00ae8> { _evt14_softirq + 0x0 }

physical IVG15 asserted : <0xffa00e60> { _evt_system_call + 0x0 }

logical irq 6 mapped : <0xffa00250> { _timer_interrupt + 0x0 }

logical irq 18 mapped : <0x00095bf4> { _bfin_serial_rx_int + 0x0 }

logical irq 19 mapped : <0x00095e10> { _bfin_serial_tx_int + 0x0 }

logical irq 24 mapped : <0x0009eb90> { _bf537mac_interrupt + 0x0 }

RETE: <0x00000000> { _run_init_process + 0xfffff000 }

BUG: scheduling while atomic: swapper/0/0x04010000

SEQUENCER STATUS: Not tainted

SEQSTAT: 00002000 IPEND: ffff SYSCFG: 0006

HWERRCAUSE: 0x0

EXCAUSE : 0x0

physical IVG6 asserted : <0xffa00df4> { _evt_timer + 0x0 }

physical IVG7 asserted : <0xffa00e0c> { _evt_evt7 + 0x0 }

physical IVG8 asserted : <0xffa00e18> { _evt_evt8 + 0x0 }

physical IVG9 asserted : <0xffa00e24> { _evt_evt9 + 0x0 }

physical IVG10 asserted : <0xffa00e30> { _evt_evt10 + 0x0 }

physical IVG11 asserted : <0xffa00e3c> { _evt_evt11 + 0x0 }

physical IVG12 asserted : <0xffa00e48> { _evt_evt12 + 0x0 }

physical IVG13 asserted : <0xffa00e54> { _evt_evt13 + 0x0 }

physical IVG14 asserted : <0xffa00ae8> { _evt14_softirq + 0x0 }

physical IVG15 asserted : <0xffa00e60> { _evt_system_call + 0x0 }

logical irq 6 mapped : <0xffa00250> { _timer_interrupt + 0x0 }

logical irq 18 mapped : <0x00095bf4> { _bfin_serial_rx_int + 0x0 }

logical irq 19 mapped : <0x00095e10> { _bfin_serial_tx_int + 0x0 }

logical irq 24 mapped : <0x0009eb90> { _bf537mac_interrupt + 0x0 }

RETE: <0x00000000> { _run_init_process + 0xfffff000 }

RETN: <0x008ae000> /* unknown address */

RETX: <0x001710a0> { _bfin_init_mmr_debugfs + 0x4f8 }

RETS: <0xffa00216> { _cpu_idle + 0x12 }

PC : <0xffa00244> { _default_idle + 0x28 }

PROCESSOR STATE:

R0 : 00000000 R1 : 0000ffff R2 : 00000008 R3 : 00000065

R4 : 00000000 R5 : 00000000 R6 : 00000000 R7 : 00148884

P0 : ffa00a08 P1 : 00168000 P2 : 00168000 P3 : 00148890

P4 : 001819fc P5 : 00156f08 FP : 00158674 SP : 00169ee0

LB0: ffa018f8 LT0: ffa018f6 LC0: 00000000

LB1: 00170aa3 LT1: 00170aa2 LC1: 00000000

B0 : 00000000 L0 : 00000000 M0 : 00000000 I0 : 20c58d00

B1 : 00000000 L1 : 00000000 M1 : 00000000 I1 : 00000000

B2 : 00000000 L2 : 00000000 M2 : 00000000 I2 : 00000000

B3 : 00000000 L3 : 00000000 M3 : 00000000 I3 : 00000000

A0.w: 000fffff A0.x: 00000000 A1.w: 00000290 A1.x: 00000000

USP : 0016a000 ASTAT: 02002020

NULL pointer access (probably)

Kernel OOPS in progress

Deferred Exception context

Double Fault

Kernel OOPS in progress

Deferred Exception context

No Valid process in current context

return address: [0x00003d2a]; contents of:

0x00003d00: 0c00 1070 482f 1c55 61f9 a0a8 5408 0808

0x00003d10: 1877 e140 0012 e100 2c18 e300 5e59 3046

0x00003d20: c682 0f98 4f6f 320f 914a [e410] 0030 0c00

0x00003d30: 1850 0000 0000 e410 0027 0c00 184a e140

SEQUENCER STATUS: Not tainted

SEQSTAT: 00062027 IPEND: ffa008fe SYSCFG: 0006

HWERRCAUSE: 0x18

EXCAUSE : 0x27

physical IVG6 asserted : <0xffa00df4> { _evt_timer + 0x0 }

physical IVG7 asserted : <0xffa00e0c> { _evt_evt7 + 0x0 }

physical IVG11 asserted : <0xffa00e3c> { _evt_evt11 + 0x0 }

logical irq 6 mapped : <0xffa00250> { _timer_interrupt + 0x0 }

logical irq 18 mapped : <0x00095bf4> { _bfin_serial_rx_int + 0x0 }

logical irq 19 mapped : <0x00095e10> { _bfin_serial_tx_int + 0x0 }

logical irq 24 mapped : <0x0009eb90> { _bf537mac_interrupt + 0x0 }

RETE: <0x00000000> { _run_init_process + 0xfffff000 }

RETN: <0x03366568> [ klogd + 0x66568 ]

RETX: <0x00003d2a> { _dump_bfin_process + 0x46 }

RETS: <0x00003d1e> { _dump_bfin_process + 0x3a }

PC : <0xffa008fe> { _system_call + 0x22 }

DCPLB_FAULT_ADDR: <0x000000c0> /* Maybe null pointer? */

ICPLB_FAULT_ADDR: <0x00003d2a> { _dump_bfin_process + 0x46 }

PROCESSOR STATE:

R0 : 03366568 R1 : 00000001 R2 : 0000001f R3 : 0000001f

R4 : 03319bc4 R5 : 0000100d R6 : 00000003 R7 : 03366000

P0 : 0000000a P1 : 03366000 P2 : 00000000 P3 : 03366d64

P4 : ffe02014 P5 : 03366640 FP : 03366804 SP : 0336648c

LB0: 0330c7ee LT0: 0330c7ee LC0: 00000000

LB1: 0330b7ed LT1: 0330b7ec LC1: 00000000

B0 : 00000000 L0 : 00000000 M0 : 00000000 I0 : 03366e74

B1 : 00000000 L1 : 00000000 M1 : 00000000 I1 : 0335c04c

B2 : 00000000 L2 : 00000000 M2 : 00000000 I2 : 00000000

B3 : 00000000 L3 : 00000000 M3 : 00000000 I3 : 00000000

A0.w: 00000000 A0.x: 00000000 A1.w: 00000000 A1.x: 00000000

USP : 03366eb4 ASTAT: 02003004

Kernel panic - not syncing: Double Fault - unrecoverable event

Follow-ups

--- Robin Getz 2008-03-13 15:37:20

I see this on the branch as well as trunk, and I think I broke it - so I will

fix it.

-Robin

--- Robin Getz 2008-03-17 17:57:11

This should be fixed on the trunk and 2008R1 branch.

Mike - can you test out?

-Robin

--- Mike Frysinger 2008-03-17 19:20:43

works for me

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