From: Rafael J. Wysocki Date: Thu, 14 Nov 2013 22:26:58 +0000 (+0100) Subject: PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps() X-Git-Tag: v3.13-rc1~28^2~1^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6a0c7cd33075f6b7f1d80145bb19812beb3fc5c9;p=pandora-kernel.git PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps() I have received a report about the BUG_ON() in free_basic_memory_bitmaps() triggering mysteriously during an aborted s2disk hibernation attempt. The only way I can explain that is that /dev/snapshot was first opened for writing (resume mode), then closed and then opened again for reading and closed again without freezing tasks. In that case the first invocation of snapshot_open() would set the free_bitmaps flag in snapshot_state, which is a static variable. That flag wouldn't be cleared later and the second invocation of snapshot_open() would just leave it like that, so the subsequent snapshot_release() would see data->frozen set and free_basic_memory_bitmaps() would be called unnecessarily. To prevent that from happening clear data->free_bitmaps in snapshot_open() when the file is being opened for reading (hibernate mode). In addition to that, replace the BUG_ON() in free_basic_memory_bitmaps() with a WARN_ON() as the kernel can continue just fine if the condition checked by that macro occurs. Fixes: aab172891542 (PM / hibernate: Fix user space driven resume regression) Reported-by: Oliver Lorenz Signed-off-by: Rafael J. Wysocki Cc: 3.12+ # 3.12+ --- Reading git-diff-tree failed