[PATCH v2 2/3] Generic handling of multi-page exclusions

Atsushi Kumagai kumagai-atsushi at mxc.nes.nec.co.jp
Mon Apr 14 21:18:31 PDT 2014

>> At that time, I chose the current code since it was simpler and safer.
>> http://www.mail-archive.com/kexec%40lists.infradead.org/msg10207.html
>> Don't you like this ?
>Sorry. I had forgotten this. We should keep the sanity check
>there. But in our policy, we should not pass to set_bitmap_cyclic(),
>pfn and cycle where pfn is not in the cycle. We should chceck that in
>the caller side and pass pfn in the cycle only.
>Also, on the current implementation, even if pfn outside a current
>cycle is passed to set_bitmap_cyclic(), we don't have any means to
>know that.
>So, how about warning that only once at runtime?

Sounds good, it will be helpful to detect bugs in caller side.
Like this?

diff --git a/makedumpfile.c b/makedumpfile.c
index 75092a8..da960ad 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -3361,9 +3361,16 @@ int
 set_bitmap_cyclic(char *bitmap, unsigned long long pfn, int val, struct cycle *cycle)
 	int byte, bit;
+	static int warning = 0;
-        if (pfn < cycle->start_pfn || cycle->end_pfn <= pfn)
+        if (pfn < cycle->start_pfn || cycle->end_pfn <= pfn) {
+		if (!warning) {
+			MSG("WARNING: PFN out of cycle range. (pfn:%llx, ", pfn);
+			MSG("cycle:[%llx-%llx])\n", cycle->start_pfn, cycle->end_pfn);
+			warning = 1;
+		}
                 return FALSE;
+	}
 	 * If val is 0, clear bit on the bitmap.

Atsushi Kumagai

More information about the kexec mailing list