Re: [Crash-utility] Re: crash-4.0-4.3 and linux-2.6.22.1-20.fc7

> > Using the latest F7 kernel and crash I'm getting the following > > error: > > WARNING: cannot read linux_banner string > > crash: /usr/lib/debug/lib/modules/2.6.22.1-20.fc7/vmlinux and > > /dev/crash do not match! > > I've tried both crash and crash -f with no luck. > > I've search the mailing list and was unable to find any > > thing talked about this problem... So I'm thinking this > > may not be a known problem... If it is, please let me know > > otherwise does anybody have idea what the problem could be? > > tia, > > steved. > > > > This elephant still remains in the room... > > I can reproduce it with a 2.6.21-1.3194.fc7 kernel, which > I believe has 2.6.22 stuff backported to it. Don't know about the Fedora kernel, but at least in mainline __pa/__va still work as before for i386/x86-64. It's a single add/sub on i386 and on x86-64 similar, but with different ranges for kernel text vs the other kernel memory. The load address is variable now, but still has a default set at compile time in CONFIG. What might have changed when you enable the relocatable kernel is that the ELF addresses in the vmlinux are different. But at runtime there is no difference. -Andi

Hi Dave, Sorry, could not reply on Friday. This looks weared. Only one possible theory comes to mind. In FC7 kernels following should be config variables. CONFIG_PHYSICAL_START=16MB CONFIG_PHYSICAL_ALIGN=4MB. That means kernel has been compiled for 16MB physical address. That's why linux_banner symbol address is in higher range. But at run time it has been loaded by grub at 1MB location. Because alignment required is 4MB kernel will move itself to physical address 4MB and that would probably put linux banner somewhere at 6MB location. So these kind of problems will occur with first kernel is not run at the address it has been compiled for. Can you please confirm this by looking at FC7 config file. An easy way to fix this would be to change CONFIG_PHYSICAL_START=1MB. Thanks Vivek