Messages in this thread | | | Date | Wed, 19 Feb 2003 21:07:22 -0800 | From | William Lee Irwin III <> | Subject | Re: doublefault debugging (was Re: Linux v2.5.62 --- spontaneous reboots) |
| |
On Wed, Feb 19, 2003 at 08:52:46PM -0800, Linus Torvalds wrote: > Whee. So the double-fault patch actually ends up being useful? It didn't > help with Chris' problem, but hey, if it helps with something else.. > Anyway, that %esp is crap, which also explains this: >> 0xc01181c4 <do_page_fault+20>: mov %eax,0xc(%esp,1) > Took a page fault because 0xc(%esp) wasn't there, and the page fault > couldn't write the fault trace to the stack (same reason), so you got a > double fault.
Not sure where he got his %esp, but I extracted the following:
<zwane> MAXMEM=0x33e00000 <zwane> vmalloc: start = 0xf3e1f000, end = 0xfbe21000 <zwane> fixaddr: start = 0xfbe23000, end = 0xfffff000
which means somehow %esp landed in an unmapped tidbit in the middle of of vmallocspace that isn't even mapped. I highly suspect rounding errors of mine since I squished vmallocspace, fixmapspace, and the physical mapping so close together they might share L3 pagetables, i.e. they're separated by 2*MMUPAGE_SIZE instead of customary 8MB or so.
-- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |