[PATCH 4.19 201/321] tools/vm/page-types.c: fix "kpagecount returned fewer pages than expected" failures

[Greg Kroah-Hartman]

From: Anthony Yznaga <anthony.yznaga@xxxxxxxxxx>

[ Upstream commit b6fb87b8e3ff1ef6bcf68470f24a97c984554d5a ]

Because kpagecount_read() fakes success if map counts are not being
collected, clamp the page count passed to it by walk_pfn() to the pages
value returned by the preceding call to kpageflags_read().

Link: http://lkml.kernel.org/r/1543962269-26116-1-git-send-email-anthony.yznaga@xxxxxxxxxx
Fixes: 7f1d23e60718 ("tools/vm/page-types.c: include shared map counts")
Signed-off-by: Anthony Yznaga <anthony.yznaga@xxxxxxxxxx>
Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 tools/vm/page-types.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c
index 37908a83ddc27..1ff3a6c0367b0 100644
--- a/tools/vm/page-types.c
+++ b/tools/vm/page-types.c
@@ -701,7 +701,7 @@ static void walk_pfn(unsigned long voffset,
 		if (kpagecgroup_read(cgi, index, pages) != pages)
 			fatal("kpagecgroup returned fewer pages than expected");
 
-		if (kpagecount_read(cnt, index, batch) != pages)
+		if (kpagecount_read(cnt, index, pages) != pages)
 			fatal("kpagecount returned fewer pages than expected");
 
 		for (i = 0; i < pages; i++)
-- 
2.20.1