From 56511628fa6714b189509b2842eadce0842bfeb5 Mon Sep 17 00:00:00 2001

From: Mikhail Zaslonko <zaslonko@linux.ibm.com>

Date: Mon, 4 Nov 2019 14:05:15 +0100

Subject: [PATCH] [PATCH] Fix off-by-one issue in exclude_nodata_pages()

When building a dump bitmap (2nd bitmap) for the ELF dump, the last pfn

of the cycle is always ignored in exclude_nodata_pages() function due to

off-by-one error on cycle boundary check. Thus, the respective bit of

the bitmap is never cleared.

That can lead to the error when such a pfn should not be dumpable (e.g.

the last pfn of the ELF-load of zero filesize). Based on the bit in the

bitmap the page is treated as dumpable in write_elf_pages_cyclic() function

and the follow on error is triggered in write_elf_load_segment() function

due to the failing sanity check of paddr_to_offset2():

   $ makedumpfile -E dump.elf dump.elf.E

   Checking for memory holes                         : [100.0 %] |

   write_elf_load_segment: Can't convert physaddr(7ffff000) to an offset.

   makedumpfile Failed.

Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>

---

 makedumpfile.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/makedumpfile-1.6.6/makedumpfile.c b/makedumpfile-1.6.6/makedumpfile.c

index de0973f9e763..4a000112ba59 100644

--- a/makedumpfile-1.6.6/makedumpfile.c

+++ b/makedumpfile-1.6.6/makedumpfile.c

@@ -4740,7 +4740,7 @@ exclude_nodata_pages(struct cycle *cycle)

 		if (pfn < cycle->start_pfn)

 			pfn = cycle->start_pfn;

 		if (pfn_end >= cycle->end_pfn)

-			pfn_end = cycle->end_pfn - 1;

+			pfn_end = cycle->end_pfn;

 		while (pfn < pfn_end) {

 			clear_bit_on_2nd_bitmap(pfn, cycle);

 			++pfn;

-- 

2.17.1