----- "Simon Kagstrom" <simon.kagstrom@xxxxxxxxxxxxxx> wrote: > Hi! > > I'm having problems getting kdumps from my relocatable kernel (2.6.31-8) > working with crash on a IA-32 board. I use makedumpfile to generate a > compressed dump, and when I try to load it with crash I get > > ./crash vmlinux vmcore --reloc=0x100000 > crash: invalid kernel virtual address: 98 type: "present" > WARNING: cannot read cpu_present_map > crash: invalid kernel virtual address: 908bd975 type: "online" > WARNING: cannot read cpu_online_map > crash: cannot determine base kernel version > crash: vmlinux and vmcore do not match! > > specifying --reloc also fails: > > ./crash vmlinux vmcore --reloc=0x100000 > crash: seek error: kernel virtual address: c01a2108 type: > "cpu_possible_mask" > > > So I started looking into the code and found something which looks like > a typo in relocate() (patch below). Changing this makes crash work for me. Actually it's not a typo -- your patch would presumably break with all kernels that have a CONFIG_PHYSICAL_START is greater than CONFIG_PHYSICAL_ALIGN, which is what the patch was written to handle. What are your kernel's CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN values? Does crash work with your kernel on the live system? Anyway, I believe that the fix would require support for supplying a negative --reloc value. > > Great tool by the way, leaves you longing for the next kernel panic > ;-) > > // Simon > > --- orig-crash-4.1.2/symbols.c 2009-12-09 21:37:40.000000000 +0100 > +++ crash-4.1.2/symbols.c 2009-12-17 16:03:24.000000000 +0100 > @@ -671,7 +671,7 @@ relocate(ulong symval, char *symname, in > break; > } > > - return (symval - kt->relocate); > + return (symval + kt->relocate); > } > > /* -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
