Takao Indoh wrote:
> Hi, I found a problem on crash-4.0-2.12.
>
> Summary:
> bt command does not show stack traces of some CPUs.
>
> Condition:
> This problem happens only on ia64 machine.
> There are two conditions to reproduce this problem.
> 1) Diskdump is executed via OS_INIT.
> 2) The machine has more than 8 CPUs.
>
> Details:
> When I executed bt command for vmcore which was created
> on the 32 CPU machine, bt didn't show stack traces of some CPU.
> Please see attached file(bt_failed.txt). Stack traces from CPU0 to
> CPU7 are showed normally, but stack traces from CPU8 to CPU31 are not.
> (Please don't worry about a message "unwind: bsp (xxxxxxxxx) out of
> range". This is a problem of our platform.)
>
> Cause:
> I found a bug in ia64.c.
>
> 2679 ms->ia64_init_stack_size = get_array_length("ia64_init_stack",
> 2680 NULL, 0);
>
> get_array_length() gets the length of stack of OS_INIT, and the
> length is stored at ms->ia64_init_stack_size. However, the value
> which get_array_length gives is different from actual stack length
> because "ia64_init_stack" is declared like this:
>
> u64 ia64_init_stack[NR_CPUS*KERNEL_STACK_SIZE/8];
>
> Therefore, correct length of a stack is this:
> get_array_length("ia64_init_stack", NULL, 0) * sizeof(u64)
>
> I don't know how to fix, but it seems that attached patch
> (ia64.c.patch) corrects this problem.
> Another attached patch(test.patch) also seems to fix the problem,
> but I don't know which is better.
>
Hello Takao,
Welcome to the list!
I prefer your second "test.patch" because it seems to be a much cleaner
way to get the size from gdb.
Thanks for tracking this down,
Dave
>
> Regards,
> Takao Indoh
>
> ------------------------------------------------------------------------------------------------------------------------
> Name: bt_failed.txt
> bt_failed.txt Type: Plain Text (text/plain)
> Encoding: base64
>
> Name: ia64.c.patch
> ia64.c.patch Type: unspecified type (application/octet-stream)
> Encoding: base64
> Download Status: Not downloaded with message
>
> Name: test.patch
> test.patch Type: unspecified type (application/octet-stream)
> Encoding: base64
> Download Status: Not downloaded with message
>
> ------------------------------------------------------------------------------------------------------------------------
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