Commits
Kirill A. Shutemov committed 591a3d7c09f
mm: Fix false-positive VM_BUG_ON() in page_cache_{get,add}_speculative()
0day testing by Fengguang Wu triggered this crash while running Trinity:
kernel BUG at include/linux/pagemap.h:151!
...
CPU: 0 PID: 458 Comm: trinity-c0 Not tainted 4.11.0-rc2-00251-g2947ba0 #1
...
Call Trace:
__get_user_pages_fast()
get_user_pages_fast()
get_futex_key()
futex_requeue()
do_futex()
SyS_futex()
do_syscall_64()
entry_SYSCALL64_slow_path()
It' VM_BUG_ON() due to false-negative in_atomic(). We call
page_cache_get_speculative() with disabled local interrupts.
It should be atomic enough.
So let's check for disabled interrupts in the VM_BUG_ON() condition
too, to resolve this.
( This got triggered by the conversion of the x86 GUP code to the
generic GUP code. )
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: LKP <lkp@01.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170324114709.pcytvyb3d6ajux33@black.fi.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>