Hi, I am using Linux Kernel version 2.6.13. In one of the processes, I am modifying the timer manually using mod_timer function. The system generates an oops inconsistently. The log is as follows: ---------------------------------------------------------------------------- -------------------------- kernel BUG at kernel/timer.c:449! Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0778000 [00000000] *pgd=a0cb2031, *pte=00000000, *ppte=00000000 Internal error: Oops: 817 [#1] Modules linked in: scullc affix_tcs affix_uart affix_rfcomm affix snd_pcm_oss snd_mixer_oss snd_pxa2xx_ac97rom [<c00323c0>] (vprintk+0x268/0x2ac) r8 = 00000017 r7 = C02536C1 r6 = C0CCACC0 r5 = 00000000 r4 = C02536B0 [<c0032158>] (vprintk+0x0/0x2ac) from [<c0032420>] (printk+0x1c/0x20) [<c0032404>] (printk+0x0/0x20) from [<bf126120>] (scullc_write+0x34/0x48 [scullc]) r3 = C0258678 r2 = 00000001 r1 = 00000001 r0 = BF126B40 [<bf1260ec>] (scullc_write+0x0/0x48 [scullc]) from [<c006dd6c>] (vfs_write+0xc8/0x140) r4 = 00000217 [<c006dca4>] (vfs_write+0x0/0x140) from [<c006dea4>] (sys_write+0x4c/0x74) [<c006de58>] (sys_write+0x0/0x74) from [<c0019bc0>] (ret_fast_syscall+0x0/0x2c) r8 = C0019D44 r7 = 00000004 r6 = BEF9ABE1 r5 = 00000217 r4 = 00000217 Code: 1b004ee3 e59f0014 eb004ee1 e3a03000 (e5833000) <0>Kernel panic - not syncing: Aiee, killing interrupt handler! ---------------------------------------------------------------------------- -------------------------- We have analysed the the opps and the fuction causing the problem was traced to "cascade" function in timer.c. The comparision between two timer base is not same, as expected, and oops is generated. What exactly is the timer base why the timer base from the list is changing? Can any one suggest some solution or at least provide some pointer?? ~Abu. Abu M. Muttalib Sr. Engineer, Embedded System, Aftek Infosys Ltd., Pune, India Office: 91-20-25449260-65 X-256 Mobile: (0)9881322820 Email: abum@xxxxxxxxx -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
