Openmoko Bug #2369: cat s3c2440-uart.1/clock_source causes oops in s3c24xx_serial_show_clksrc

[Openmoko Public Trac]

#2369: cat s3c2440-uart.1/clock_source causes oops in s3c24xx_serial_show_clksrc
--------------------+-------------------------------------------------------
 Reporter:  lindi   |          Owner:  openmoko-kernel
     Type:  defect  |         Status:  new            
 Priority:  normal  |      Milestone:                 
Component:  kernel  |        Version:  unspecified    
 Severity:  normal  |       Keywords:                 
 Haspatch:  0       |      Blockedby:                 
Estimated:          |    Patchreview:                 
 Blocking:          |   Reproducible:  always         
--------------------+-------------------------------------------------------

Comment(by gena2x):

 Here, i can reproduce it, but it seem fails only before port were opened
 for the first time.
 {{{
 neo:~# uname -a
 Linux neo 2.6.34b5-v28 #11 Sun Oct 31 17:54:41 MSK 2010 armv4tl GNU/Linux
 }}}

 (kernel from radek's .29 tree + jitterless ts patch v4)

 fresh booted kernel:
 {{{

 Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
 permitted by applicable law.
 neo:~# cat /sys/devices/platform/s3c2440-uart.1/clock_source
 Segmentation fault
 neo:~# cat /sys/devices/platform/s3c2440-uart.1/clock_source
 Segmentation fault
 neo:~# cat /dev/ttySAC1
 $GPRMC,,V,,,,,,,,,,N*53

 $GPVTG,,,,,,,,,N*30

 $GPGGA,,,,,,0,00,99.99,,,,,,*48

 $GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99*30

 $GPGSV,1,1,00*79

 $GPGLL,,,,,,V,N*64

 $GPZDA,,,,,00,00*48

 ^C
 neo:~# cat /sys/devices/platform/s3c2440-uart.1/clock_source
 * pclk

 }}}

 ops:
 {{{
 [   53.710000] Unable to handle kernel NULL pointer dereference at virtual
 address 00000000
 [   53.710000] pgd = c483c000
 [   53.710000] [00000000] *pgd=34834031, *pte=00000000, *ppte=00000000
 [   53.710000] Internal error: Oops: 17 [#2]
 [   53.710000] last sysfs file:
 /sys/devices/platform/s3c2440-uart.1/clock_source
 [   53.710000] Modules linked in: rfcomm l2cap ipv6 ppp_generic slhc
 g_ether joydev s3c2410_udc
 [   53.710000] CPU: 0    Tainted: G      D     (2.6.34b5-v28 #11)
 [   53.710000] PC is at s3c24xx_serial_show_clksrc+0x20/0x34
 [   53.710000] LR is at s3c24xx_serial_show_clksrc+0x14/0x34
 [   53.710000] pc : [<c02407dc>]    lr : [<c02407d0>]    psr: a0000013
 [   53.710000] sp : c482dec0  ip : c482dec0  fp : c482ded4
 [   53.710000] r10: c482df78  r9 : c482c000  r8 : 00001000
 [   53.710000] r7 : c048dc28  r6 : c03b9a74  r5 : c7d344dc  r4 : c4825000
 [   53.710000] r3 : 00000000  r2 : c4825000  r1 : 00001000  r0 : c4825000
 [   53.710000] Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM
 Segment user
 [   53.710000] Control: c000717f  Table: 3483c000  DAC: 00000015
 [   53.710000] Process cat (pid: 1611, stack limit = 0xc482c270)
 [   53.710000] Stack: (0xc482dec0 to 0xc482e000)
 [   53.710000] dec0: c04a1cb4 c7d344dc c482deec c482ded8 c024119c c02407cc
 c7d46860 c7d344dc
 [   53.710000] dee0: c482df14 c482def0 c00e3420 c0241180 c7d46860 c7d46878
 c6ed44a0 00015000
 [   53.710000] df00: 00001000 c482c000 c482df44 c482df18 c00e3514 c00e33d0
 bebfec50 00000000
 [   53.710000] df20: c6ed44a0 00001000 00015000 c482df78 c0029044 40025000
 c482df74 c482df48
 [   53.710000] df40: c0099c18 c00e349c 00000000 00008124 00000001 c6ed44a0
 00000000 00000000
 [   53.710000] df60: 00000003 c0029044 c482dfa4 c482df78 c0099da4 c0099b70
 00000000 00000000
 [   53.710000] df80: 00001000 00000000 00000000 00001000 00015000 00015000
 00000000 c482dfa8
 [   53.710000] dfa0: c0028ec0 c0099d68 00001000 00015000 00000003 00015000
 00001000 00015000
 [   53.710000] dfc0: 00001000 00015000 00015000 00000003 7fffe000 00000000
 40025000 00000000
 [   53.710000] dfe0: 00000003 bebfebb8 0000ad20 400d9d5c 60000010 00000003
 00000000 00000000
 [   53.710000] Backtrace:
 [   53.710000] [<c02407bc>] (s3c24xx_serial_show_clksrc+0x0/0x34) from
 [<c024119c>] (dev_attr_show+0x2c/0x4c)
 [   53.710000]  r5:c7d344dc r4:c04a1cb4
 [   53.710000] [<c0241170>] (dev_attr_show+0x0/0x4c) from [<c00e3420>]
 (fill_read_buffer+0x60/0xcc)
 [   53.710000]  r5:c7d344dc r4:c7d46860
 [   53.710000] [<c00e33c0>] (fill_read_buffer+0x0/0xcc) from [<c00e3514>]
 (sysfs_read_file+0x88/0x94)
 [   53.710000]  r9:c482c000 r8:00001000 r7:00015000 r6:c6ed44a0
 r5:c7d46878
 [   53.710000] r4:c7d46860
 [   53.710000] [<c00e348c>] (sysfs_read_file+0x0/0x94) from [<c0099c18>]
 (vfs_read+0xb8/0x16c)
 [   53.710000] [<c0099b60>] (vfs_read+0x0/0x16c) from [<c0099da4>]
 (sys_read+0x4c/0x84)
 [   53.710000]  r8:c0029044 r7:00000003 r6:00000000 r5:00000000
 r4:c6ed44a0
 [   53.710000] [<c0099d58>] (sys_read+0x0/0x84) from [<c0028ec0>]
 (ret_fast_syscall+0x0/0x2c)
 [   53.710000]  r6:00015000 r5:00015000 r4:00001000
 [   53.710000] Code: eb000e3f e510300c e3a01a01 e1a00004 (e5933000)
 [   53.710000] ---[ end trace 6eee0da881bf3030 ]---
 }}}

-- 
Ticket URL: <https://docs.openmoko.org/trac/ticket/2369#comment:2>
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