[Crash-utility] [PATCH] Do not create arch-specific p2m mapping for ELF xen dumps

Hello Dave, Let me send you a cleanup/fix for Xen DomU dumps. When opening a Xen DomU dump without auto-translated addresses (e.g. from an x86_64 PV domain), a mapping between physical and machine pages is needed. An xc_core dump file does not contain this mapping, so it must be created by arch-specific code from the dumped data. This (and only this) is the job of the machdep->xendump_p2m_create callback, which is called if the XC_CORE_P2M_CREATE flag is set. ELF files contain the mapping in a separate section (".xen_p2m"), so this arch-specific code is not needed and should not be run. On the other hand, XC_CORE_P2M_CREATE also triggers the initialization of the elf_index_pfn array. I believe this should be in fact controlled by XC_CORE_PFN_CREATE, because the flag is not used for anything else. I found this issue thanks to a Xen DomU ELF dump file that contained an invalid CR3 value, which could not be used to translate kvaddr to maddr. Without the patch, session initialization fails with these messages: crash: cannot find mfn 0 (0x0) in page index crash: cannot read/find pud page Signed-off-by: Petr Tesarik <ptesarik(a)suse.com&gt;