diff options
authorPrarit Bhargava <prarit@redhat.com>2008-09-09 09:56:08 -0400
committerH. Peter Anvin <hpa@zytor.com>2008-09-09 11:54:53 -0700
commitd6be118a97ce51ca84035270f91c2bccecbfac5f (patch)
parent14469a8dd23677921db5e7354a602c98d9c6300f (diff)
x86: fix memmap=exactmap boot argument
When using kdump modifying the e820 map is yielding strange results. For example starting with BIOS-provided physical RAM map: BIOS-e820: 0000000000000100 - 0000000000093400 (usable) BIOS-e820: 0000000000093400 - 00000000000a0000 (reserved) BIOS-e820: 0000000000100000 - 000000003fee0000 (usable) BIOS-e820: 000000003fee0000 - 000000003fef3000 (ACPI data) BIOS-e820: 000000003fef3000 - 000000003ff80000 (ACPI NVS) BIOS-e820: 000000003ff80000 - 0000000040000000 (reserved) BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved) BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved) BIOS-e820: 00000000fee00000 - 00000000fee01000 (reserved) BIOS-e820: 00000000ff000000 - 0000000100000000 (reserved) and booting with args memmap=exactmap memmap=640K@0K memmap=5228K@16384K memmap=125188K@22252K memmap=76K#1047424K memmap=564K#1047500K resulted in: user-defined physical RAM map: user: 0000000000000000 - 0000000000093400 (usable) user: 0000000000093400 - 00000000000a0000 (reserved) user: 0000000000100000 - 000000003fee0000 (usable) user: 000000003fee0000 - 000000003fef3000 (ACPI data) user: 000000003fef3000 - 000000003ff80000 (ACPI NVS) user: 000000003ff80000 - 0000000040000000 (reserved) user: 00000000e0000000 - 00000000f0000000 (reserved) user: 00000000fec00000 - 00000000fec10000 (reserved) user: 00000000fee00000 - 00000000fee01000 (reserved) user: 00000000ff000000 - 0000000100000000 (reserved) But should have resulted in: user-defined physical RAM map: user: 0000000000000000 - 00000000000a0000 (usable) user: 0000000001000000 - 000000000151b000 (usable) user: 00000000015bb000 - 0000000008ffc000 (usable) user: 000000003fee0000 - 000000003ff80000 (ACPI data) This is happening because of an improper usage of strcmp() in the e820 parsing code. The strcmp() always returns !0 and never resets the value for e820.nr_map and returns an incorrect user-defined map. This patch fixes the problem. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 9af89078f7bb..66e48aa2dd1b 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -1203,7 +1203,7 @@ static int __init parse_memmap_opt(char *p)
if (!p)
return -EINVAL;
- if (!strcmp(p, "exactmap")) {
+ if (!strncmp(p, "exactmap", 8)) {
* If we are doing a crash dump, we still need to know

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