range: Do not add new blank slot with add_range_with_merge (05418815) · Commits · 戴 / test

Joshua reported: Commit cd7b304dfaf1 (x86, range: fix missing merge during add range) broke mtrr cleanup on his setup in 3.9.5. corresponding commit in upstream is . The reason is add_range_with_merge could generate blank spot. We could avoid that by searching new expanded start/end, that new range should include all connected ranges in range array. At last add the new expanded start/end to the range array. Also move up left array so do not add new blank slot in the range array. -v2: move left array to avoid enhance add_range() -v3: include fix from Joshua about memmove declaring when DYN_DEBUG is used. Reported-by:

Joshua Covington <joshuacov@googlemail.com> Tested-by:

Joshua Covington <joshuacov@googlemail.com> Signed-off-by:

Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1371154622-8929-3-git-send-email-yinghai@kernel.org Cc: <stable@vger.kernel.org> v3.9 Signed-off-by:

H. Peter Anvin <hpa@linux.intel.com>

kernel/range.c

+11 −10

Original line number	Diff line number	Diff line
		@@ -4,7 +4,7 @@
		#include <linux/kernel.h>
		#include <linux/init.h>
		#include <linux/sort.h>

		#include <linux/string.h>
		#include <linux/range.h>

		int add_range(struct range *range, int az, int nr_range, u64 start, u64 end)
		@@ -32,9 +32,8 @@ int add_range_with_merge(struct range *range, int az, int nr_range,
		if (start >= end)
		return nr_range;

		/* Try to merge it with old one: */
		/* get new start/end: */
		for (i = 0; i < nr_range; i++) {
		u64 final_start, final_end;
		u64 common_start, common_end;

		if (!range[i].end)
		@@ -45,14 +44,16 @@ int add_range_with_merge(struct range *range, int az, int nr_range,
		if (common_start > common_end)
		continue;

		final_start = min(range[i].start, start);
		final_end = max(range[i].end, end);
		/* new start/end, will add it back at last */
		start = min(range[i].start, start);
		end = max(range[i].end, end);

		/* clear it and add it back for further merge */
		range[i].start = 0;
		range[i].end = 0;
		return add_range_with_merge(range, az, nr_range,
		final_start, final_end);
		memmove(&range[i], &range[i + 1],
		(nr_range - (i + 1)) * sizeof(range[i]));
		range[nr_range - 1].start = 0;
		range[nr_range - 1].end = 0;
		nr_range--;
		i--;
		}

		/* Need to add it: */

Admin message