December 2011 - kernelnewbies@kernelnewbies.org

multiple definition error from dl-addr.c with addition of printf, in glibc compilation
by solmac john Dec. 10, 2011

Dec. 10, 2011

Hi All, in glibc-2.13/nptl/sigaction.c, i just put a simple printf("test\n"); and my glibc compilation fails. Just adding a printf gives me multiple definitions of _itoa from dl-addr.c and i have no idea why. Can any body please tell me why is this happening and possible solution. For better clarity here is the error: Error msg :- test/glibc-build/libc_pic.a(_itoa.os): In function `_itoa': test/glibc-2.13/stdio-common/_itoa.c:215: multiple definition of `_itoa' test/glibc-build/elf/dl-allobjs.os:test/glibc-2.13/elf/dl-minimal.c:300: first defined here test/glibc-build/libc_pic.a(dl-addr.os): In function `_dl_addr_inside_object': test/SOURCE/glibc-2.13/elf/dl-addr.c:156: multiple definition of `_dl_addr_inside_object' test/glibc-build/elf/dl-allobjs.os:glibc-2.13/elf/dl-open.c:658: first defined here Thanks, Akhilesh

3 5

Problem with OOM killer killing process even when there is plenty of RAM.
by mindentropy Dec. 9, 2011

Dec. 9, 2011

Hi, I am trying to allocate 512MB of RAM in my driver loaded as a module, but the OOM killer starts killing all my processes. This machine has around 24GB RAM and is a 8 core Xeon. The RAM is allocated in page size chunks (i.e. 131072 chunks each of size PAGE_SIZE). I am using a 32 bit kernel with PAE enabled. The allocation works fine on a machine with 8GB of RAM. Thanks.

5 10

VFAT i_pos value
by Kai Meyer Dec. 9, 2011

Dec. 9, 2011

I'm getting this error: FAT: Filesystem error (dev sblsnap0) fat_get_cluster: invalid cluster chain (i_pos 523791) I'm wondering if there was a way to figure out what sector is causing the error? I would like to try and track down what is changing that sector and fix the problem. Is there a straight forward way to convert i_pos to a sector value? I've been staring at the fat.c and fat.h code all morning, and I'm having trouble grok'ing the flow. -Kai Meyer

3 9

What does inconsistent lock state mean?
by Kai Meyer Dec. 8, 2011

Dec. 8, 2011

I'm getting this when I try to spin_unlock a recently acquired lock with spin_lock. IRQs are still somewhat of a mystery to me, and cryptic lock state symbols (IN-HARDIRQ-W, HARDIRQ-ON-W) are unintelligible to me. Dec 7 15:52:20 dev2 kernel: ================================= Dec 7 15:52:20 dev2 kernel: [ INFO: inconsistent lock state ] Dec 7 15:52:20 dev2 kernel: 2.6.32-220.el6.x86_64.debug #1 Dec 7 15:52:20 dev2 kernel: --------------------------------- Dec 7 15:52:20 dev2 kernel: inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. Looking at lockdep.c isn't giving me any help either. It's obfuscated beyond my ability to grok by simply reading the code. It seems like this portion should help me, but it doesn't.... Dec 7 15:52:20 dev2 kernel: {IN-HARDIRQ-W} state was registered at: Dec 7 15:52:20 dev2 kernel: [<ffffffff810afbca>] __lock_acquire+0x77a/0x1570 Dec 7 15:52:20 dev2 kernel: [<ffffffff810b0a64>] lock_acquire+0xa4/0x120 Dec 7 15:52:20 dev2 kernel: [<ffffffff81520c75>] _spin_lock_irqsave+0x55/0xa0 Dec 7 15:52:20 dev2 kernel: [<ffffffffa006b19b>] blk_done+0x2b/0x110 [virtio_blk] Dec 7 15:52:20 dev2 kernel: [<ffffffffa00401dc>] vring_interrupt+0x3c/0xd0 [virtio_ring] Dec 7 15:52:20 dev2 kernel: [<ffffffff810ec080>] handle_IRQ_event+0x50/0x160 Dec 7 15:52:20 dev2 kernel: [<ffffffff810ee840>] handle_edge_irq+0xe0/0x170 Dec 7 15:52:20 dev2 kernel: [<ffffffff8100e059>] handle_irq+0x49/0xa0 Dec 7 15:52:20 dev2 kernel: [<ffffffff81526cdc>] do_IRQ+0x6c/0xf0 Dec 7 15:52:20 dev2 kernel: [<ffffffff8100ba93>] ret_from_intr+0x0/0x16 Dec 7 15:52:20 dev2 kernel: [<ffffffff810148e2>] default_idle+0x52/0xc0 Dec 7 15:52:20 dev2 kernel: [<ffffffff81009e0b>] cpu_idle+0xbb/0x110 Dec 7 15:52:20 dev2 kernel: [<ffffffff81516623>] start_secondary+0x211/0x254 Then later it tells me that I'm holding 1 lock, which is the one that I mentioned at the beginning that was just recently locked.

2 3

percpu variables from softirq context
by Vimal Dec. 8, 2011

Dec. 8, 2011

Hi, I am trying to allocate a per-cpu variable from a softirq context, but the documentation for "alloc_percpu" says that the variable is allocated in GFP_KERNEL context, which can sleep. Is there a way around this? Thanks, -- Vimal

2 2

Measuring time in range of microseconds.
by Sathishkumar Duraisamy Dec. 7, 2011

Dec. 7, 2011

Hi, I am writing a module to measure time taken between two events. I have to measure time in microseconds. Some articles says about High resolution timers. As per the article http://elinux.org/High_Resolution_Timers, I read cat /proc/timer_list which says 10000000ns as resolution ( which is 10ms). I think with this resolution I cannot measure in the range of microseconds. I couldn't able to find support for HR timer in kernel menuconfig. I am using kernel 2.6.36.2. Can you please help me to, "How do enable this timer. Or is there any other means to measure time or simply I have to use the timer hardware directly?" -- With Thanks, Sathishkumar D http://flowersopenlab.weebly.com/

4 7

drm/i915 can't work without intel_agp module
by ashish anand Dec. 7, 2011

Dec. 7, 2011

Hi I am using fedora 16 and trying to compile linux kernel 3.0.4 .Everything seems to be fine but when i am trying to boot through my kernel 3.0.4 it is throwing error drm/i915 can't work without intel_agp module. Now what i could figure out is that I am having nvidea geforce graphic card in my pc and as i am using default configuration to built my kernel so probably some problem might be related to graphic driver(just guesing).I am stuck. Please help. Thanks and Regards Ashish Anand

2 1

Bug:scheduling while atomic..
by sandeep kumar Dec. 5, 2011

Dec. 5, 2011

Hi all, here is the dump i got in dmesg... <3>[ 4940.803872] BUG: scheduling while atomic: rild/144/0x00000908 <4>[ 4940.803895] Modules linked in: mwlan_aarp(P) bthid <4>[ 4940.803918] <4>[ 4940.803927] Pid: 144, comm: rild <4>[ 4940.803943] CPU: 0 Tainted: P W (2.6.38.6 #1) <4>[ 4940.803973] PC is at dpram_write+0x3e4/0x848 <4>[ 4940.803988] LR is at 0xad <4>[ 4940.804002] pc : [<c03b8b80>] lr : [<000000ad>] psr: 20000013 <4>[ 4940.804010] sp : e8379e50 ip : c09a4578 fp : e8379e8c <4>[ 4940.804022] r10: e8308450 r9 : e89d5400 r8 : e849ba40 <4>[ 4940.804037] r7 : e89d5400 r6 : 0000000d r5 : 0000000d r4 : c078f324 <4>[ 4940.804050] r3 : fa14c4b0 r2 : 000001ad r1 : 00000008 r0 : 0000007e <4>[ 4940.804067] Flags: nzCv IRQs on FIQs on Mode SVC_ate -2017760, reprogram it <3>[ 4940.915690] msm_timer_enter_idlable: 2853c059 DAC: 00000015 <4>[ 4940.804095] <4>[ 4940.804098] PC: 0xc03b8b00: <4>[ 4940.804, reprogram it <3>[ 4940.915719]fc07c e142c0b1 e2400001 e3110001 e1a000c0 02632000 <4>[ 4940.804148] 8b20 0a00000b ea000003 e551c001 e5512002 e182240c e0c320b2 e3500000 e2811002 <4>[ 4940.804188] 8b40 e2400001 1afffff7 ea0000b6 e19cc0b1 e0c3c0b2 e3500000 e083c002 e2400001 <4>[ 4940.804-2019424, reprogram it <3>[ 494025005 e5933000 e1560005 b1a05006 a1a05005 e3550000 <4>[ 4940.804270] 8b80 da00004d e0822001 e1aer_idle: timer late -2019968, re 0a00000e e3170001 <4>[ 4940.804310] 8ba0 e2450001 015320b1 01d710b0 115310b1 115720b1 06ef2072 01822401 16ef1071 <4>[ 4940.804350] 8bc0 13c220ff 11822001 06ff2072 e2871001 e14320b1 e2833001 e3100001 0a000022 <4>[ 4940.804390] 8be0 e2432001 e241c001 e0822000 e08cc000 e3120001 e20ce001 1a000006 e35e0000 <4>[ 4940.804432] <4>[ 4940.804435] SP: 0xe8379dd0: <4>[ 4940.804443] 9dd0 e8379dec e8379de0 c00b1644 c00b14c4 e8379e04 e8379df0 c0033084 c00b1600 <4>[ 4940.804485] 9df0 ffffffff fa000000 e8379e8c e8379e08 c003918c c003300c 0000007e 00000008 <4>[ 4940.804523] 9e10 000001ad fa14c4b0 c078f324 0000000d 0000000d e89d5400 e849ba40 e89d5400 <4>[ 4940.804563] 9e30 e8308450 e8379e8c c09a4578 e8379e50 000000ad c03b8b80 20000013 ffffffff <4>[ 4940.804603] 9e50 60000013 e8379ec0 e8379e7c 01ad01ad c04dd664 e8308000 0000000d e89d5400 <4>[ 4940.804643] 9e70 e8378000 e849ba40 e89d5400 e8308it <3>[ 4940.915979] msm_timer_e03b87a8 <4>[ 4940.804683] 9e90 e8379ef4 e8379ea0 c025f3a0 c03b8ff0 c02623e0 c04dd650 e83080d0 e8308158 <4>[ 4940.804723] 9eb0 e8379ef4 00000000 e83746c0 c00a8imer late -2024128, reprogram it8308000 <4>[ 4940.804765] <4>[ 4940.804768] IP: 0xc09a44f8: <4>[ 4940.804777] 44f8 00000000 00000000 c074b1c0 e8b49200 e8b3266024672, reprogram it <3>[ 4940.9nter_idle: timer late -2513888, 000000 00000000 00000000 e92b4e60 00000001 e8b4d000 00000001 <4>[ 4940.804855] 4538 00000001 00000001 00000000 00000000 00000000 00000000 00000000 e926de00 <4>[ 4940.804893] 4558 e8b32460 00094] msm_timer_enter_idle: timer8 00000000 e8b7db60 e8b854a8 <4>[ 4940.804933] 4578 fa14c4b0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.804972] 4598 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.805010] 45b8 00000000 00000000 00000000 00000000 00000005808, reprogram it <3>[ 4940.941[ 4940.805048] 45d8 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.805088] <4>[ 4940.805092e -2027424, reprogram it <3>[ 4900] 9e0c 00000008 000001ad fa14c4b0 c078f324 0000000d 0000000d e89d5400 e849ba40 <4>[ 4940.805138] 9e2c e89d5400 e8308450 e8379e8c c09a4578 e8379e50 000000ad c03b8b80 20000013 <4>[ 4940.805178] 9e4c ffffffff 60000013 e8379ec0 e8379e7c 01ad01ad c04dd664 e8308000 0000000d <4>[ 4940.805218] 9e6c e89d5400 e8378000 e849ba40 e89d5400 e8308450 e8379e9c program it <3>[ 4940.916265] msm58] 9e8c c03b87a8 e8379ef4 e8379ea0 c025f3a0 c03b8ff0 c02623e0 c04dd650 e83080d0 <4>[ 4940.805298] 9eac e8308158 e8379ef4 00000000 e83746c0 c00a89ac e8377bec e8308168 e849ba40 <4>[ 4940.805338] 9ecc e8308000 0000000d e849ba40 e8378000 0000000d 0001e7d0 0000000d e8379f3c <4>[ 4940.805378] 9eec e8379ef8 c025c280 c025f0d8 00000018 c025f0cc e836b520 [ 4940.916337] msm_timer_enter_i20] <4>[ 4940.805423] R3: 0xfa14c430: <4>[ 4940.805432] c430 0er_enter_idle: timer late -2030700 00000000 00000000 00000000 00000000 <4>[ 4940.805472] c450 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.805512] c470 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.805550] c490 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.805590] c4b0 000100aa 01ad01ad 00127f7e 3a000fit <3>[ 4940.916439] msm_timer_e0b7f7e <4>[ 4940.805630] c4d0 3b000816 04031300 0f7f7e00 000c170272, reprogram it <3>[ 4940.96718000b <4>[ 4940.805672] c4f0 13003d00 7e000401 1900127f 003e000f 06050113 38013100 7e303031 1a <3>[ 4940.916480] msm_timer_ent03f0008 00040313 000f7f7e 40000c1b 05031300 00040003 0b7f7e00 00081c00 <4>[ 4940.805755] <4>[ 4940.805758] R4: 0xc078f2a4: <4>[ 4940.805767] f2a4 00000000 00000000 00000000 00000000 00000000 00000000 e8b8cf60 c0563518 <4>[_idle: timer late -2034048, repr00000 c078f2cc c078f2cc c078f300 c078f310 00000000 c069ea3b <4>[ 4940.805845] f2e4 000001b4 c03b3004 00000000 c069ea47 000001b4 c03b3054 00000000 c0643eea <4>[ 4940.805885] f304 000001b4 c03b2fd0 c03b3a8c c069ea50 000001b442046] msm_timer_enter_idle: tim 4940.805925] f324 00002000 00002002 00002004 000003fc 00000004 00000006 00000008 000003fc <4>[ 4940.805963] f344 00080020 00000002 e8308000 00000001 00000001 dead4ead ffffffff ffffffff <4>[ 4940.806003] f364 00000001 c078f368 c078f368 00002400 00002402 00002404 00005bf8 00000404 <4>[ 4940.806043] f384 00000406 00000408 00001bf8 00040010 00000001 00000000 00000000 00000001 <4>[ 4940.806083] <4>[ 4940.806087] R7: 0xe89d5380: <4>[ 4940.806095] 5380 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806132] 53a0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806170] 53c0 00000000 00000000 00000000 00000000 00000000 00000000 0program it <3>[ 4940.916725] msm8] 53e0 00000000 00000000 00000037920, reprogram it <3>[ 4940.90000000 00000000 <4>[ 4940.806247] 5400 30000b7f 00550008 00040113 0000047e 7e30307e 0100007e 007e0100 00000000 <4>[ 4940.806287] 5420 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806325] 5440 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806363] 5460 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806402] <4>[ 4940.806405] R8: 0xe849b9c0: <4>[ 4940.806413] b9c0 ffffffff 00000002 00000002 00000003 00000000 00000000 deaf1eed fff9056, reprogram it <3>[ 4940.942ffffff 00000000 00000000 00000000 00000000 00000000 e8dde5c0 00000000 <4>[ 4940.806492] ba00 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806530] ba20 00000000 00000000 e8e667c0 e849ba2c e849ba2c e8e668d4 00000000 00000000 <4>[ 4940.806568] ba40 e849bc20 e849bcc0 e9210300 e8de5478 c0545ec8 00000001 dead4ead ffffffff <4>[ 4940.806608] ba60 ffffffff 00000004 00020802 00000003 00000000 00000000 deaf1eed ffffffff <4>[ 4940.806648] ba80 ffffffff 00000000 00000000 00000000 00000000 00000000 e8dde5c0 000 timer late -2531264, reprogram 000000 00000000 00000000 00000000 00000000 00000000 ffffffff ffffffff <4>[ 4940.806727] <4>[ 4940.806730] R9: 0xe89d5380: <4>[ 4940.806738] 5380 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806775] 53a0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806813] 53c0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806852] 53e0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806890] 5400 30000b7f 00550008 00040113 0000047e 7e30307e e: timer late -2044576, reprogra4940.806930] 5420 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 <4>[ 4940.806967] 5440 00000000 00000000 00000000 00000000 00000000 er_enter_idle: timer late -253434940.807005] 5460 00000000 00000000 00000000 00000000 00000000 nter_idle: timer late -2045664, 4940.807045] <4>[ 4940.807048] e: timer late -2534848, reprogra-2045952, reprogram it <3>[ 4940000 00000000 00000000 00000000 e8383000 00000000 <4>[ 4940.80709r late -2146945184, reprogram it000 00000000 00000001 00000001 dead4ead ffffffff <4>[ 4940.807133] 8410 ffffffff e8308414 e8308414 e8376000 00000000 e8308400 00000000 00000001 <4>[ 4940.807173] 8430 dead4ead ffffffff fffff3>[ 4940.917215] msm_timer_enter0000000 e8308428 <4>[ 4940.807213] 8450 00000001 00000001 dead4ead ffffffff ffffffff e8308464 e7616, reprogram it <3>[ 4940.917er_idle: timer late -2536800, ree: timer late -9850304, reprografffffff e830848c <4>[ 4940.807292] 8490 e830848c e8522000 00000000 e8308478 e89d5400 00000400 00000001 dead4ead <4>[ 4940.807332] 84b0 ffffffff ffffffff 00000200 e83084bc e83084bc c025bdcc 0ogram it <3>[ 4940.942764] msm_t5] [<c003b0e8>] (show_regs+0x0/0 <3>[ 4940.968228] msm_timer_enter_idle: timer late -3026816, re10] r5:c075dac0 r4:e8379e08 <4>, reprogram it <3>[ 4940.917330]chedule_bug+0x0/0x60) from [<c04daa48>] (schedule+0x88/0x5c8) <4>[ 4940.807453] r5:c075dac0 r4:e83746c0 <4>[ 4940.807478] [<c04da9c0>] (schedule+0x0/0x5c8) from [<c04db1e4>] (schedule_timeout+0x24/0x1e4) <4>[ 4940.807502] [<c04db1c0>] (schedule_timeout+0x0/0x1e4) from [<c04dc9a8>] (__down+0x74/0xa8) <4>[ 4940.807517] r7:00000002 r6:e83746c0 r5:7fffffff r4:c078f428 <4>[ 4940.807550] [<c04dc934>] (__down+0x0/0xa8) from [<c00ca394>] (down+0x34/0x44) <4>[ 4940.807563] r7:e8b9b6ec r6:00000033 r5:60000013 r4:c078f428 <4>[ 4940.807597] [<c00ca360>] (down+0x0/0x44) from [<c03>[ 4940.917447] msm_timer_enter) <4>[ 4940.807610] r5:e8b9b6ec r4:c078f370 <4>[ 4940.807635] [<c03b879c>] (dpram_write+0x0/0x848) from [<c03b90b8>] (vs_write+0xb4/0xf4) <4>[ 4940.807658] [<c03b9004>] (vs_write+0x0/0xf4) from [<c02cea5c>] (ppp_async_push+0x10c/0x570) <4>[ 4940.807680] [<c02ce950>] (ppp_async_push+0x0/0x570) from [<c02cef10>] (ppp_async_send+0x50/0x58) <4>[ 4940.809] msm_timer_enter_idle: timer late -2053152, reprogram it <3>[ ppp_push+0x74/0x5c4) <4>[ 4940.807722] r5:caf9c0d4 r4:c80abc00 <4>[ 4940.807748] [<c02ca9dc>] (ppp_push+0x0/0x5c4) from [<c02cba3c>] (ppp_xmit_process+0x430/0x4ec) <4>[ 4940.807773] [<c02cb60c>] (ppp_xmit_process+0x0/0x4ec) from [<c02cbc94>] (ppp_start_xm3>[ 4940.968501] msm_timer_enter] [<c02cbaf8>] (ppp_start_xmit+0x0/0x1c8) from [<c03cc490>] (devimer_enter_idle: timer late -303>[ 4940.807813] r7:e0bcba5c r6:c80ab800 r5:00002000 r4:e839de20.917619] msm_timer_enter_idle: t(dev_hard_start_xmit+0x0/0x554) from [<c03dfe7c>] (sch_direct_xmit+0x68/0x1b4) <4>[ 4940.807877] [<c03dfe14>] (sch_direct_xmit+0x0/0x1b4) from [<c03cc7d8>] (dev055648, reprogram it <3>[ 4940.940.807902] [<c03cc5bc>] (dev_queue_xmit+0x0/0x42c) from [<c040dd3>[ 4940.917677] msm_timer_enter1c) <4>[ 4940.807925] [<c040da48>] (ip_finish_output+0x0/0x31c) from [<c040de50>] (ip_output+0xec/0x100) <4>[ 4940.807948] [<c040dd64>] (ip_output+0x0/0x100) from [<c040cd14>] (ip_local_out+0x30/0x34) <4>[ 4940.807962] r9:e8379b6c r8:00000040 r6:e853c660 r5:e92efc20 r4:e839de20 <4>[ 4940.808000] [<c040cce4>] (ip_local_out+0x0/0x34) from [<c040d028>] (ip_push_pending_frames+0x310/0x3b0) <4>[ 4940.808015] r5:e92efc20 r4:e839de20 <4>[ 4940.808040] [<c040cd18>] (ip_push_pending_frames+0x0/0x3b0) from [<c040d2ac>] (ip_send_reply+0x1e4/0x20c) <4>[ 4940.808065] [<c040d0c8>] (ip_send_reply+0x0/0x20c) from [e -2058400, reprogram it <3>[ 49x140/0x16c) <4>[ 4940.808088] [<c0424890>] (tcp_v4_send_reset+0x0/0x16c) from [<c0426924>] (tcp_v4_rcv+0x7e0/0x84c) <4>[ 4940.808103] r6:c800b038 r5:00000000 r4:e839dca0 <4>[ 4940.808133] [<c0426144>] (tcp_v4_rcv+0x0/0x84c) from [<c040899c>] (ip_local_delimer late -2059488, reprogram it40.808157] [<c040887c>] (ip_local_deliver_finish+0x0/0x228) from [<c0408b30>] (ip_local_deliver+0x8c/0x9c) <4>[ 4940.808172] r9:00000000 r8:00a6518a r7:00000000 r6:00a65748 r5:c800b024 <4>[ 4940.808198] r4:e839dca0 <4>[ 4940.808217] [<c0408aa4>] (ip_local_deliver+0x0/0x9c) from [<c0408538>] (ip_rcv_finish+0x324/0x344) <4>[ 4940.808232] r4:e839dca0 <4>[ 4940.808250] [<c0408214>] (ip_rcv_finish+0x0/0x344) from [<c0408838>] (ip_rcv+0x2e0/0x324) <4>[ 4940.808263] r9:00000000 r8:00a6518a r7:00000000 r6:00a65743425] msm_timer_enter_idle: tim r4:e839dca0 <4>[ 4940.808310] [<c0408558>] (ip_rcv+0x0/0x324) from [<c03ca974>] (__netif_receive_skb+0x34c/0x3a4) <4>[ 4940.808325] r9:00000008 r8:e8379cfc r7:e839dd48 r6:c0740ff8 r5:c80ab800 <4>[ 4940.808352] r4:e839dca0 <4>[ 4940.808370] [<c03ca628>] (__netif_receive_skb+0x0/0x3a4) from [<c03caa54>] (process_backlog+0x88/0x138) <4>[ 4940.808393] [<c03ca9cc>] (process_backlog+0x0/0x138) from [<c03cadcc>] (net_rx_action+0x70/0x160) <4>[ 4940.808417] [<c03cad5c>] (net_rx_action+0x0/0x160) from [<c00b1540>] (__do_softirq+0x88/0x13c) <4>[ 4940.808440] [<c00b14b8>] (__do_softirq+0x0/0x13c) from [<c00b1644>] (irq_exit+0x50/0xa4) <4>[ 4940.808465] [<c00b15f4>] (irq_exit+0x0/0xa4) from [<c0033084>] (program it <3>[ 4940.918108] msm_timer_enter_idle: timer late -2+0x0/0xa8) from [<c003918c>] (__irq_svc+0x4c/0x90) <4>[ 4940.808503] Exception stack(0xe8379e08 to 0xe8379e50) <4>[ 4940.808522] 9e00: 0000007e 00000008 000001ad fa14c4b0 c078f324 0000000d <4>[ 4940.808543] 9e20: 0000000d e89d5400 e849ba40 e89d5400 e8308450 e8379e8c c09a4578 e8379e50 <4>[ 4940.808560]_timer_enter_idle: timer late -23 ffffffff <4>[ 4940.808572] r5:fa000000 r4:ffffffff <4>[ 4940.808598] [<c03b879c>] (dpram_write+0x0/0x848) from [<c03b9000>] (dpram_tty_write+0x1c/0x20) <4>[ 4940.808623] [<c03b8fe4>] (dpram_tty_write+0x0/0x20) from [<c025f3a0>] (n_tty_write+0x2d4/0x3c0) <4>[ 4940.808652] [<c025f0cc>] (n_tty_write+0x0/0x3c0) from [<c025c280>] (tty_write+0x190/0x230) <4>[ 4940.808678] [<c025c0f0>] (tty_write+0x0/0x230) from [<c0123d90>] (vfs_write+0xb8/0x144) <4>[ 4940.808703] [<c0123cd8>] (vfs_write+0x0/0x144) from [<c0123ee0>] (sys_write+0x44/0x70) <4>[ 4940.808717] r8:0000000d r7:00000000 r6:00000000 r5:0001e7d0 r4:e849ba40 <4>[ 4940.808755] [<c0123e9c>] (sys_write+0x0/0x70) from [<c0039680>] (ret_fast_syscall+0x0/0x30) <4>[ 4940.808770] er_idle: timer late -2068640, re1300 r5:0000000d r4:00000000 I felt, something is wrong in dpram_write function, But couldnt exactly know what happend. Even i tried disassembling the function, i traced to some normal jump instruction. I know this error comes when, some function sleeps in atomic context. Can anyone pls help me in fixing this.. THanks -- With regards, Sandeep Kumar Anantapalli,

2 2

which context can't use queue_work() function?
by onlyfever Dec. 5, 2011

Dec. 5, 2011

Hi, I have a question about work queue. I use queue_work() function in my TTY driver's write function (ch_tty_write()). The TTY driver works fine,but when this driver is called from ppp_write() function system would crash. static int ch_tty_write(struct tty_struct *tty, const unsigned char *buf, int count) { ...... queue_work(xxx,xxxx); return count; } I want to know which context can't use queue_work() function? Put the crash message below. Unable to handle kernel NULL pointer dereference at virtual address 00000003 pgd = df344000 [00000003] *pgd=9f3c8031, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] PREEMPT last sysfs file: /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state Modules linked in: CPU: 0 Not tainted (2.6.35.7-g76a4056-svn-dirty #453) PC is at __wake_up_common+0x20/0x78 LR is at __wake_up+0x44/0x7c pc : [<c006f29c>] lr : [<c00727e8>] psr: 80000093 sp : df197e48 ip : c05fb1ef fp : df197e6c r10: 00000000 r9 : 00000000 r8 : 00000003 r7 : 00000003 r6 : c06bcd14 r5 : 00000001 r4 : 00000093 r3 : 00000000 r2 : 00000001 r1 : 00000003 r0 : 00000003 Flags: Nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user Control: 10c5387d Table: 9f344019 DAC: 00000015 PC: 0xc006f21c: f21c e3a01000 e92d4830 e28db00c e5932430 e3520000 c3a02e47 d3002468 e18340d2 f23c e0944000 e0a55001 e18340f2 e8bd8830 c069d128 e92d4800 e28db004 e8bd4800 f25c eaffffe1 e92d4800 e28db004 e8bd4800 eaffffe9 e92d4800 e28db004 e8bd8800 f27c e92d4ff8 e1a06000 e5900000 e28db024 e1a08001 e1a05002 e1a0a003 e59b9004 f29c e410400c e244400c ea00000e e590c008 e1a01008 e1a0200a e1a03009 e5907000 f2bc e12fff3c e3500000 0a000003 e3170001 0a000001 e2555001 08bd8ff8 e594300c f2dc e1a00004 e243400c e280300c e1530006 1affffed e8bd8ff8 e92d4800 e28db004 f2fc e24dd008 e3a03000 e3a02001 e58d3000 ebffffda e24bd004 e8bd8800 e92d4800 LR: 0xc0072768: 2768 e3c23d7f e3c3303f e5933000 e3130002 0a000002 e24bd018 e8bd49f0 ea11529e 2788 e24bd018 e8bd89f0 e92d4800 e3a03000 e28db004 e8bd4800 eaffffd9 e92d49f0 27a8 e28db018 e24dd00c e1a05000 e1a07001 e1a06002 e1a08003 e10f4000 f10c0080 27c8 e3a00001 ebfff86a e3a03000 e1a00005 e1a01007 e1a02006 e58d8000 ebfff2a4 27e8 e121f004 e3a00001 ebfff832 e1a0200d e3c23d7f e3c3303f e5933000 e3130002 2808 0a000002 e24bd018 e8bd49f0 ea11527a e24bd018 e8bd89f0 e92d48f0 e28db014 2828 e24dd008 e24b1018 e1a04000 ebfff882 e594604c e5907414 e1a05000 e1570004 2848 13a07000 03a07001 e3560000 0a000002 e1a01004 e3a02000 ebfff9cd e3570000 SP: 0xdf197dc8: 7dc8 c06a822c 00000056 80000013 c007e288 80000013 c003b070 60000013 ffffffff 7de8 fa200000 ffffffff df197e34 c06bcd14 00000003 c003ba6c 00000003 00000003 7e08 00000001 00000000 00000093 00000001 c06bcd14 00000003 00000003 00000000 7e28 00000000 df197e6c c05fb1ef df197e48 c00727e8 c006f29c 80000093 ffffffff 7e48 00000000 00000093 c06bcd14 00000001 00000003 00000000 dedbf800 df43c400 7e68 df197e94 c00727e8 00000000 00000001 ffffffff 60000013 c06bcd0c dedbfbbc 7e88 df1760b0 c069c018 df1760b0 c0089ccc dedbfbbc d8eee440 dedbf83c c0089d48 7ea8 00000000 c008a420 00000009 dedbf800 0000002f c005b428 df176000 df176014 IP: 0xc05fb16f: b16c 6f6e203a 6d656d20 2079726f 204a5628 706d6f63 73736572 0a29726f 6e702600 b18c 6c613e2d 70705f6c 756d5f70 00786574 503e363c 67205050 72656e65 64206369 b1ac 65766972 65762072 6f697372 2e32206e 0a322e34 3e333c00 6c696166 74206465 b1cc 6572206f 74736967 50207265 70205050 656e7265 65642074 65636976 64252820 b1ec c0000a29 3cdedbfb 61663e33 64656c69 206f7420 69676572 72657473 50505020 b20c 76656420 20656369 29642528 333c000a 5050503e 6572203a 69766f6d 6d20676e b22c 6c75646f 75622065 6e752074 20737469 616d6572 0a216e69 63702600 633e2d68 b24c 5f6e6168 006d6573 703e333c 645f7070 6d6f6365 73657270 72665f73 3a656d61 b26c 206f6e20 6f6d656d 000a7972 503e333c 203a5050 6d206f6e 726f6d65 56282079 FP: 0xdf197dec: 7dec ffffffff df197e34 c06bcd14 00000003 c003ba6c 00000003 00000003 00000001 7e0c 00000000 00000093 00000001 c06bcd14 00000003 00000003 00000000 00000000 7e2c df197e6c c05fb1ef df197e48 c00727e8 c006f29c 80000093 ffffffff 00000000 7e4c 00000093 c06bcd14 00000001 00000003 00000000 dedbf800 df43c400 df197e94 7e6c c00727e8 00000000 00000001 ffffffff 60000013 c06bcd0c dedbfbbc df1760b0 7e8c c069c018 df1760b0 c0089ccc dedbfbbc d8eee440 dedbf83c c0089d48 00000000 7eac c008a420 00000009 dedbf800 0000002f c005b428 df176000 df176014 00000016 7ecc 00000000 0000002f c02abfd8 00000053 df176014 00000002 de964800 00000016 R6: 0xc06bcc94: cc94 00000000 00000000 c06bcca4 dfd352c0 00000000 00000000 c02a757c c02a752c ccb4 c02a757c c02a752c 00000000 c02a74e4 00000000 00000000 00000000 00000000 ccd4 00000000 00000000 00000000 00000000 00000000 de9c7d80 de9c7dc0 00000000 ccf4 00000000 c0020610 c04bf808 00000000 c077ebd4 00000030 00005403 dedbfbc0 cd14 00000003 00000000 c02ac7a4 c02ac464 00000000 00000000 c02ab68c c02ab694 cd34 c02abd8c 00000000 00000000 c02ab69c c02ac510 c02ab8fc c02ab880 00000000 cd54 00000000 00000001 00000080 c02ac414 c02ac520 00005403 c05fb4ee 0000000e cd74 00000000 c02ad530 c02ad1fc 00000000 00000000 c02ac9b8 c02ac9c0 c02acd94 Process pppd (pid: 1681, stack limit = 0xdf1962e8) Stack: (0xdf197e48 to 0xdf198000) 7e40: 00000000 00000093 c06bcd14 00000001 00000003 00000000 7e60: dedbf800 df43c400 df197e94 c00727e8 00000000 00000001 ffffffff 60000013 7e80: c06bcd0c dedbfbbc df1760b0 c069c018 df1760b0 c0089ccc dedbfbbc d8eee440 7ea0: dedbf83c c0089d48 00000000 c008a420 00000009 dedbf800 0000002f c005b428 7ec0: df176000 df176014 00000016 00000000 0000002f c02abfd8 00000053 df176014 7ee0: 00000002 de964800 00000016 00000001 df1770aa dedbf884 df1760b1 00000000 7f00: 00000000 df176000 df636b40 df636b40 df636b40 00000000 00000000 fffffcec 7f20: 00000000 c02ac45c c02ac414 db9c51c0 db9c51c4 c02aa394 00000016 db9c51c0 7f40: 0006d212 c02aa504 df197f80 00000016 df3d9ac0 0006d212 df197f80 c00e8d8c 7f60: df3d9ac0 0006d212 df3d9ac0 0006d212 00000016 00000004 00000000 c00e8ed4 7f80: 00000000 00000000 00000016 00000000 00000016 0006d212 00027548 c003c0c4 7fa0: df196000 c003bf40 00000016 0006d212 0000000b 0006d212 00000016 00000000 7fc0: 00000016 0006d212 00027548 00000004 00000001 0001fa86 fffffcec 00000000 7fe0: 0002769c bee61a18 0001a027 afd0b47c 20000010 0000000b 80c06021 80c06421 [<c006f29c>] (__wake_up_common+0x20/0x78) from [<c00727e8>] (__wake_up+0x44/0x7c) [<c00727e8>] (__wake_up+0x44/0x7c) from [<c0089ccc>] (__queue_work+0x2c/0x58) [<c0089ccc>] (__queue_work+0x2c/0x58) from [<c0089d48>] (queue_work_on+0x50/0x5c) [<c0089d48>] (queue_work_on+0x50/0x5c) from [<c008a420>] (queue_work+0x24/0x54) [<c008a420>] (queue_work+0x24/0x54) from [<c005b428>] (ch_tty_write+0x80/0xa4) [<c005b428>] (ch_tty_write+0x80/0xa4) from [<c02abfd8>] (ppp_async_push+0xe4/0x520) [<c02abfd8>] (ppp_async_push+0xe4/0x520) from [<c02ac45c>] (ppp_async_send+0x48/0x50) [<c02ac45c>] (ppp_async_send+0x48/0x50) from [<c02aa394>] (ppp_channel_push+0x48/0xc0) [<c02aa394>] (ppp_channel_push+0x48/0xc0) from [<c02aa504>] (ppp_write+0xf8/0x100) [<c02aa504>] (ppp_write+0xf8/0x100) from [<c00e8d8c>] (vfs_write+0xb0/0x148) [<c00e8d8c>] (vfs_write+0xb0/0x148) from [<c00e8ed4>] (sys_write+0x3c/0x68) [<c00e8ed4>] (sys_write+0x3c/0x68) from [<c003bf40>] (ret_fast_syscall+0x0/0x30) Code: e1a08001 e1a05002 e1a0a003 e59b9004 (e410400c) ---[ end trace d4cfc85b433d01fb ]--- Kernel panic - not syncing: Fatal exception in interrupt [<c0040c50>] (unwind_backtrace+0x0/0xe4) from [<c04c6b78>] (panic+0x54/0xdc) [<c04c6b78>] (panic+0x54/0xdc) from [<c003f884>] (die+0x1a0/0x1dc) [<c003f884>] (die+0x1a0/0x1dc) from [<c00419cc>] (__do_kernel_fault+0x64/0x84) [<c00419cc>] (__do_kernel_fault+0x64/0x84) from [<c0041c84>] (do_page_fault+0x298/0x2b8) [<c0041c84>] (do_page_fault+0x298/0x2b8) from [<c003b2ec>] (do_DataAbort+0x34/0x98) [<c003b2ec>] (do_DataAbort+0x34/0x98) from [<c003ba6c>] (__dabt_svc+0x4c/0x60) Exception stack(0xdf197e00 to 0xdf197e48) 7e00: 00000003 00000003 00000001 00000000 00000093 00000001 c06bcd14 00000003 7e20: 00000003 00000000 00000000 df197e6c c05fb1ef df197e48 c00727e8 c006f29c 7e40: 80000093 ffffffff [<c003ba6c>] (__dabt_svc+0x4c/0x60) from [<c006f29c>] (__wake_up_common+0x20/0x78) [<c006f29c>] (__wake_up_common+0x20/0x78) from [<c00727e8>] (__wake_up+0x44/0x7c) [<c00727e8>] (__wake_up+0x44/0x7c) from [<c0089ccc>] (__queue_work+0x2c/0x58) [<c0089ccc>] (__queue_work+0x2c/0x58) from [<c0089d48>] (queue_work_on+0x50/0x5c) [<c0089d48>] (queue_work_on+0x50/0x5c) from [<c008a420>] (queue_work+0x24/0x54) [<c008a420>] (queue_work+0x24/0x54) from [<c005b428>] (ch_tty_write+0x80/0xa4) [<c005b428>] (ch_tty_write+0x80/0xa4) from [<c02abfd8>] (ppp_async_push+0xe4/0x520) [<c02abfd8>] (ppp_async_push+0xe4/0x520) from [<c02ac45c>] (ppp_async_send+0x48/0x50) [<c02ac45c>] (ppp_async_send+0x48/0x50) from [<c02aa394>] (ppp_channel_push+0x48/0xc0) [<c02aa394>] (ppp_channel_push+0x48/0xc0) from [<c02aa504>] (ppp_write+0xf8/0x100) [<c02aa504>] (ppp_write+0xf8/0x100) from [<c00e8d8c>] (vfs_write+0xb0/0x148) [<c00e8d8c>] (vfs_write+0xb0/0x148) from [<c00e8ed4>] (sys_write+0x3c/0x68) [<c00e8ed4>] (sys_write+0x3c/0x68) from [<c003bf40>] (ret_fast_syscall+0x0/0x30) Rebooting in 1 seconds.. thanks. Regards!

2 2

What is Backing device used for?
by loody Dec. 5, 2011

Dec. 5, 2011

Dear all: Is there any document which explain what "backing device" used for? -- Thanks a lot,

4 3