Re: [Fwd: [Crash-utility] crash warnings]

Hi Dave, Like Badari's issue, which actually was a non-issue, it's difficult to debug from here. A couple things... When you use an additional System.map argument on the command line, you should see the message stating that several thousand symbol values are being changed from what is in the vmlinux file to what is in the System.map file: please wait... (patching ##### gdb minimal_symbol values) This gets kicked off in the gdb_interface.c gdb_session_init() function here: /* * Patch gdb's symbol values with the correct values from either * the System.map or non-debug vmlinux, whichever is in effect. */ if ((pc->flags & SYSMAP) || (pc->namelist_debug && !pc->debuginfo_file)) { req->command = GNU_PATCH_SYMBOL_VALUES; req->flags = GNU_RETURN_ON_ERROR; gdb_interface(req); if (req->flags & GNU_COMMAND_FAILED) error(FATAL, "patching of gdb symbol values failed\n"); } So, presuming that worked OK, what's strange is the read error you get on the vmcore: >crash: read error: kernel virtual address: c00000000fa26940 type: "first vmlist addr" > The first_vmalloc_address() function is simply reading reading the contents of the vmlist pointer, which points to the first vm_struct in the list, and which is returning c00000000fa26940. But then it fails to read what's in the "addr" offset of the vm_struct at that address: get_symbol_data("vmlist", sizeof(void *), &vmlist); if (!readmem(vmlist+OFFSET(vm_struct_addr), KVADDR, &addr, sizeof(void *), "first vmlist addr", RETURN_ON_ERROR)) non_matching_kernel(); Since the "addr" offset is 0, it just reads address c00000000fa26940, which is a just a kmalloc'd unity-mapped address. So the question is, why is that address not capable of being read from the vmcore? If you do a "help -n" to dump the header contents of the vmcore, does physical address fa26940 not fit into any of the PT_LOAD segments? (Again -- this all presumes the the "vmlist" symbol address is correct...) Dave ------------------------------------------------------------------------ -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility