On 2009-02-08 20:21, Rafael J. Wysocki wrote: > This message has been generated automatically as a part of a report > of recent regressions. > > The following bug entry is on the current list of known regressions > from 2.6.28. Please verify if it still should be listed and let me know > (either way). > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12606 > Subject : fb_mmap: circular locking dependency on hibernation > Submitter : Andrey Borzenkov <arvidjaar@xxxxxxx> > Date : 2009-01-27 18:37 (13 days old) > References : http://marc.info/?l=linux-kernel&m=123308162731408&w=4 > Handled-By : Andrea Righi <righi.andrea@xxxxxxxxx> > Patch : http://marc.info/?l=linux-kernel&m=123365581406194&w=2 This is fixed by: commit 1f5e31d7e55ac7fbd4ec5e5b20c8868b0e4564c9 Author: Andrea Righi <righi.andrea@xxxxxxxxx> Date: Wed Feb 4 15:12:03 2009 -0800 fbmem: don't call copy_from/to_user() with mutex held Avoid calling copy_from/to_user() with fb_info->lock mutex held in fbmem ioctl(). fb_mmap() is called under mm->mmap_sem (A) held, that also acquires fb_info->lock (B); fb_ioctl() takes fb_info->lock (B) and does copy_from/to_user() that might acquire mm->mmap_sem (A), causing a deadlock. NOTE: it doesn't push down the fb_info->lock in each own driver's fb_ioctl(), so there are still potential deadlocks elsewhere. Signed-off-by: Andrea Righi <righi.andrea@xxxxxxxxx> Cc: Dave Jones <davej@xxxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxxx> Cc: Krzysztof Helt <krzysztof.h1@xxxxx> Cc: Harvey Harrison <harvey.harrison@xxxxxxxxx> Cc: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
