Re: Re: [Crash-utility] crash 4.0-2.8 fails on 2.6.14-rc5 (EM64T)

> > crash: read error: kernel virtual address: ffff8100050eb084 type: > "tss_struct ist array" > I see that the 2.6.13 kernel defines its init_tss array like so: DEFINE_PER_CPU(struct tss_struct, init_tss) ____cacheline_maxaligned_in_smp; whereas, the earlier 2.6 kernels do it like this: DECLARE_PER_CPU(struct tss_struct,init_tss); If this change modifies the way that per-cpu variable addresses are laid out, then I can't tell you what to do without significant further investigation. But until proven otherwise, let's presume that the calculations of the per-cpu data is done the same way. There are two places where that error message comes from, both in x86_64_ist_init(), but given that the above per-cpu declarations are functionally equivalent, there would be the following kernel symbol in your vmlinux, verifiable like so: $ nm -Bn vmlinux | grep per_cpu__init_tss ffffffff80502100 D per_cpu__init_tss $ If it's not there, crash is hosed, then signficant work needs to be done to find it. But if the symbol is still intact in the 2.6.14 kernel, the failure should have come from an incorrect calculation of the vaddr of the init_tss below:

static void x86_64_ist_init(void) { ... } else if (symbol_exists("per_cpu__init_tss")) { for (c = 0; c < NR_CPUS; c++) { if ((kt->flags & SMP) && (kt->flags & PER_CPU_OFF)) { if (kt->__per_cpu_offset[c] == 0) break; vaddr = symbol_value ("per_cpu__init_tss") + kt->__per_cpu_offset[c]; } else vaddr = symbol_value ("per_cpu__init_tss"); vaddr += OFFSET(tss_struct_ist); readmem(vaddr, KVADDR, &ms->stkinfo.ebase [c][0], sizeof(ulong) * 7, "tss_struct ist array", FAULT_ON_ERROR);

if (ms->stkinfo.ebase[c][0] == 0) break; } } I'm also presuming your test kernel is SMP. But I'm wondering whether the SMP and PER_CPU_OFF flags are set?

The SMP flag should have been pre-set in kernel_init(), but the PER_CPU_OFF flag gets set in x86_64_cpu_pda_init(), which you have modified. You can display the kt->flags contents with a printk x86_64_ist_init (). If PER_CPU_OFF is not set, then that's probably the issue here. Can you show your new versions of x86_64_cpu_pda_init() and x86_64_get_smp_cpus()?