On Thu, Feb 23, 2006 at 09:49:37AM -0500, Dave Anderson wrote:
>
> Ok, then I guess I'll take that as a thumbs-up.
>
> Waiting on Rachita's go-ahead...

Dave,

After the application of the patch (posted by Haren)
on crash-4.0-2.21, I am now able to open the dump using crash
for analysis.

The following may be unrelated to the present discussion, but
it is an observation:

When I do 'bt -a' I get the following error on one of the cpus:

PID: 2871   TASK: c000000161d05800  CPU: 4   COMMAND: "klogd"
bt: invalid kernel virtual address: ff807a50  type: "Regs NIP value"

It looks like the ppc64_kdump_stack_frame() function is getting the
kernel stack pointer value from gpr[1] in the ELF header's pt_regs
storage location, and that stack address (+16) is hosed:

/*
 * get SP and IP from the saved ptregs.
 */
static int
ppc64_kdump_stack_frame(struct bt_info *bt_in, ulong *nip, ulong *ksp)
{
        struct ppc64_pt_regs *pt_regs;
        unsigned long unip;

        pt_regs = (struct ppc64_pt_regs *)bt_in->machdep;
        if (!pt_regs->gpr[1]) {
                /*
                 * Not collected regs. May be the corresponding CPU not
                 * responded to an IPI.
                 */
                fprintf(fp, "%0lx: GPR1 register value (SP) was not saved\n",
                        bt_in->task);
                return FALSE;
        }
        *ksp = pt_regs->gpr[1];
        readmem(*ksp+16, KVADDR, &unip, sizeof(ulong), "Regs NIP value",
                FAULT_ON_ERROR);

 

and a segmentation fault when I a do a 'bt' after setting the
context to a particular cpu using 'set -c'.

crash> set -c 8
    PID: 0
COMMAND: "swapper"
   TASK: c0000000e9faf800  (1 of 16)  [THREAD_INFO: c000000161fa4000]
    CPU: 8
  STATE: TASK_RUNNING (ACTIVE)
crash> bt
PID: 0      TASK: c0000000e9faf800  CPU: 8   COMMAND: "swapper"
Segmentation fault

Thoughts?
 

You guys are going to have to tell me what's going on...

Dave
 

 
Thanks
Rachita

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