From 46cb27f5169d37be38be8e5729b9a0100e989fa8 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 24 Feb 2009 13:12:43 -0800 Subject: [PATCH] x86: check range in reserve_early() Impact: cleanup one 32-bit system reports: BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 000000000009fc00 (usable) BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved) BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved) BIOS-e820: 0000000000100000 - 000000001c000000 (usable) BIOS-e820: 00000000ffff0000 - 0000000100000000 (reserved) DMI 2.0 present. last_pfn = 0x1c000 max_arch_pfn = 0x100000 kernel direct mapping tables up to 1c000000 @ 7000-c000 .. RAMDISK: 1bc69000 - 1bfef4fa .. 0MB HIGHMEM available. 448MB LOWMEM available. mapped low ram: 0 - 1c000000 low ram: 00000000 - 1c000000 bootmap 00002000 - 00005800 (9 early reservations) ==> bootmem [0000000000 - 001c000000] #0 [0000000000 - 0000001000] BIOS data page ==> [0000000000 - 0000001000] #1 [0000001000 - 0000002000] EX TRAMPOLINE ==> [0000001000 - 0000002000] #2 [0000006000 - 0000007000] TRAMPOLINE ==> [0000006000 - 0000007000] #3 [0000400000 - 00009ed14c] TEXT DATA BSS ==> [0000400000 - 00009ed14c] #4 [001bc69000 - 001bfef4fa] RAMDISK ==> [001bc69000 - 001bfef4fa] #5 [00009ee000 - 00009f2000] INIT_PG_TABLE ==> [00009ee000 - 00009f2000] #6 [000009f400 - 0000100000] BIOS reserved ==> [000009f400 - 0000100000] #7 [0000007000 - 0000007000] PGTABLE #8 [0000002000 - 0000006000] BOOTMAP ==> [0000002000 - 0000006000] Notice the strange blank PGTABLE entry. The reason is init_pg_table is big enough, and zero range is called with init_memory_mapping/reserve_early(). So try to check the range in reserve_early() v2: fix the reversed compare Signed-off-by: Yinghai Lu Cc: nickpiggin@yahoo.com.au Cc: ink@jurassic.park.msu.ru Signed-off-by: Ingo Molnar --- arch/x86/kernel/e820.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index e85826829cf2..508bec1cee27 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -858,6 +858,9 @@ void __init reserve_early_overlap_ok(u64 start, u64 end, char *name) */ void __init reserve_early(u64 start, u64 end, char *name) { + if (start >= end) + return; + drop_overlaps_that_are_ok(start, end); __reserve_early(start, end, name, 0); } -- 2.39.5