[PATCH 1/3] e820_update_range(): Strip size of original region

Bernhard Walle bwalle at suse.de
Wed Jun 25 08:02:20 EDT 2008

This patch fixes a bug in e820_update_range(): Previously, if a region was
partially covered, then e820_update_range() only added a new E820 range but
didn't update the end/size of the previous range. That lead to duplicate
covering of a region.

Patch tested on i386 and x86-64 with patch that uses e820_update_range()
to limit the E820 map when "mem" parameter is specified on the command line.

Signed-off-by: Bernhard Walle <bwalle at suse.de>
 arch/x86/kernel/e820.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index e285ea3..e466073 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -422,6 +422,7 @@ u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
 		final_end = min(start + size, ei->addr + ei->size);
 		if (final_start >= final_end)
+		ei->size -= final_end - final_start;
 		e820_add_region(final_start, final_end - final_start,
 		real_updated_size += final_end - final_start;

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