[Crash-utility] [Patch] linux-2.6.22 on i386

Hi Dave, I found the problem that the crash utility fails during the initialization. This problem happened on i386 linux-2.6.22 like the following: $ crash vmlinux vmcore crash 4.0-4.4 Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Red Hat, Inc. Copyright (C) 2004, 2005, 2006 IBM Corporation Copyright (C) 1999-2006 Hewlett-Packard Co Copyright (C) 2005, 2006 Fujitsu Limited Copyright (C) 2006, 2007 VA Linux Systems Japan K.K. Copyright (C) 2005 NEC Corporation Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc. Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc. This program is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Enter "help copying" to see the conditions. This program has absolutely no warranty. Enter "help warranty" for details. GNU gdb 6.1 Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "i686-pc-linux-gnu"... crash: invalid size request: 0 type: "__per_cpu_offset" $ The cause is that the array number of the symbol "__per_cpu_offset" cannot be taken. In linux-2.6.21, i386's "__per_cpu_offset" is defined in include/asm-generic/percpu.h like the following: extern unsigned long __per_cpu_offset[NR_CPUS]; But in linux-2.6.22, it is defined in include/asm-i386/percpu.h like the following, and the array number is not described in the debugging information. extern unsigned long __per_cpu_offset[]; Here is the patch for solving the problem. If the array number is not taken, the crash utility assumes that it is the defined value NR_CPUS. Or, should get_array_length() be fixed to get the array number from init/main.c ? Thanks Ken'ichi Ohmichi --- crash-4.0-4.4.org/kernel.c 2007-07-21 04:19:23.000000000 +0900 +++ crash-4.0-4.4/kernel.c 2007-07-24 19:51:55.000000000 +0900 @@ -170,7 +170,7 @@ kernel_init() else i = get_array_length("__per_cpu_offset", NULL, 0); get_symbol_data("__per_cpu_offset", - sizeof(long)*(i <= NR_CPUS ? i : NR_CPUS), + sizeof(long)*((i && (i <= NR_CPUS)) ? i : NR_CPUS), &kt->__per_cpu_offset[0]); kt->flags |= PER_CPU_OFF; } _