Re: [PATCH] lockdep: Add debug printk() for downgrade_write() warning.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello, Peter.

We got two reports. Neither RWSEM_READER_OWNED nor RWSEM_ANONYMOUSLY_OWNED is set, and
(presumably) sem->owner == current is true, but count is -1. What does this mean?

https://syzkaller.appspot.com/text?tag=CrashLog&x=169dbb9b400000

[ 2580.337550][ T3645] mmap_sem: hlock->read=1 count=-4294967295 current=ffff888050e04140, owner=ffff888050e04140
[ 2580.353526][ T3645] ------------[ cut here ]------------
[ 2580.367859][ T3645] downgrading a read lock
[ 2580.367935][ T3645] WARNING: CPU: 1 PID: 3645 at kernel/locking/lockdep.c:3572 lock_downgrade+0x35d/0xbe0
[ 2580.382206][ T3645] Kernel panic - not syncing: panic_on_warn set ...

https://syzkaller.appspot.com/text?tag=CrashLog&x=1542da4f400000

[  386.342585][T16698] mmap_sem: hlock->read=1 count=-4294967295 current=ffff8880512ae180, owner=ffff8880512ae180
[  386.348586][T16698] ------------[ cut here ]------------
[  386.357203][T16698] downgrading a read lock
[  386.357294][T16698] WARNING: CPU: 1 PID: 16698 at kernel/locking/lockdep.c:3572 lock_downgrade+0x35d/0xbe0
[  386.372148][T16698] Kernel panic - not syncing: panic_on_warn set ...





[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux