From 7c5371c403abb29f01bc6cff6c5096abdf2dc524 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Wed, 1 Jul 2009 12:32:18 -0700 Subject: x86: add boundary check for 32bit res before expand e820 resource to alignment fix hang with HIGHMEM_64G and 32bit resource. According to hpa and Linus, use (resource_size_t)-1 to fend off big ranges. Analyzed by hpa Reported-and-tested-by: Mikael Pettersson Signed-off-by: Yinghai Lu Signed-off-by: Linus Torvalds --- arch/x86/kernel/e820.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 7271fa33d79..c4ca89d9aaf 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1383,6 +1383,8 @@ static unsigned long ram_alignment(resource_size_t pos) return 32*1024*1024; } +#define MAX_RESOURCE_SIZE ((resource_size_t)-1) + void __init e820_reserve_resources_late(void) { int i; @@ -1400,17 +1402,19 @@ void __init e820_reserve_resources_late(void) * avoid stolen RAM: */ for (i = 0; i < e820.nr_map; i++) { - struct e820entry *entry = &e820_saved.map[i]; - resource_size_t start, end; + struct e820entry *entry = &e820.map[i]; + u64 start, end; if (entry->type != E820_RAM) continue; start = entry->addr + entry->size; - end = round_up(start, ram_alignment(start)); - if (start == end) + end = round_up(start, ram_alignment(start)) - 1; + if (end > MAX_RESOURCE_SIZE) + end = MAX_RESOURCE_SIZE; + if (start >= end) continue; - reserve_region_with_split(&iomem_resource, start, - end - 1, "RAM buffer"); + reserve_region_with_split(&iomem_resource, start, end, + "RAM buffer"); } } -- cgit v1.2.3-18-g5258