On Tue, 2007-05-29 at 15:45 -0400, David Anderson wrote: > Alex Sidorenko wrote: > > >Hi Dave, > > > >when I try to use 'vtop' for process pages on 2.6.20 kernel (Ubuntu/Feisty) on > >x86 architecture, I get error messages about page table. The easiest way to > >reproduce is to run 'ps -a' on a live kernel: > > > > > >PID: 0 TASK: c03a2440 CPU: 0 COMMAND: "swapper" > >ps: no user stack > > > >PID: 0 TASK: df838560 CPU: 1 COMMAND: "swapper" > >ps: no user stack > > > >PID: 1 TASK: df838a90 CPU: 1 COMMAND: "init" > >ps: read error: physical address: 7f2f0000 type: "page table" > > > > > >Running crash with -d8: > > > >PID: 1 TASK: df838a90 CPU: 1 COMMAND: "init" > ><readmem: df838a90, KVADDR, "fill_task_struct", 1328, (ROE|Q), 8d2eac0> > ><readmem: dfb71e40, KVADDR, "fill_mm_struct", 432, (ROE|Q), 8d8bf80> > > GETBUF(128 -> 1) > > FREEBUF(1) > > GETBUF(128 -> 1) > > FREEBUF(1) > > GETBUF(128 -> 1) > > FREEBUF(1) > > GETBUF(128 -> 1) > > FREEBUF(1) > >arg_start: bf991ecf arg_end: bf991ee1 (18) > >env_start: bf991ee1 env_end: bf991ff1 (272) > > GETBUF(291 -> 1) > ><readmem: dfb6f000, KVADDR, "pgd page", 4096, (FOE), 843cf90> > ><readmem: dfb6f000, KVADDR, "pmd page", 4096, (FOE), 843cf90> > ><readmem: 7f2f0000, PHYSADDR, "page table", 4096, (FOE), 843efa0> > >ps: read error: physical address: 7f2f0000 type: "page table" > > > >The same crash-4.0-4.1 works fine on live 2.6.15 kernel. Did the page table > >layout change between 2.6.15 and 2.6.20 ? > > > >Regards, > >Alex > > > I don't know. I don't have an x86 2.6.20 live system or dumpfile > readily available, > so I'll need some help from the "outside world" here... > > Anybody else know anything about this? On a 2.6.21 kernel with the -rt patchset, and crash-4.0-4.1, I see some of this: PID: 3093 TASK: f69793b0 CPU: 0 COMMAND: "mingetty" ps: cannot access user stack address: bf9fdf4c PID: 3094 TASK: f7f2abf0 CPU: 0 COMMAND: "mingetty" ps: cannot access user stack address: bfbb2f4c on i686 but I haven't seen it on x86_64. (Dave, I have these kernels, and systems with these kernels, you can access if you wish) --Guy
Attachment:
signature.asc
Description: This is a digitally signed message part
Attachment:
smime.p7s
Description: S/MIME cryptographic signature
-- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
