setup saved_max_pfn correctly (kdump) From: Magnus Damm x86_64: setup saved_max_pfn correctly 2.6.19-rc4 has broken CONFIG_CRASH_DUMP support on x86_64. It is impossible to read out the kernel contents from /proc/vmcore because saved_max_pfn is set to zero instead of the max_pfn value before the user map is setup. This happens because saved_max_pfn is initialized at parse_early_param() time, and at this time no active regions have been registered. save_max_pfn is setup from e820_end_of_ram(), more exact find_max_pfn_with_active_regions() which returns 0 because no regions exist. This patch fixes this by registering before and removing after the call to e820_end_of_ram(). Signed-off-by: Magnus Damm Signed-off-by: Andi Kleen --- Applies to 2.6.19-rc4. arch/x86_64/kernel/e820.c | 2 ++ 1 files changed, 2 insertions(+) Index: linux/arch/x86_64/kernel/e820.c =================================================================== --- linux.orig/arch/x86_64/kernel/e820.c +++ linux/arch/x86_64/kernel/e820.c @@ -594,7 +594,9 @@ static int __init parse_memmap_opt(char * size before original memory map is * reset. */ + e820_register_active_regions(0, 0, -1UL); saved_max_pfn = e820_end_of_ram(); + remove_all_active_ranges(); #endif end_pfn_map = 0; e820.nr_map = 0;