Commit ef201beb authored Aug 17, 2010 by David S. Miller

sparc64: Fix rwsem constant bug leading to hangs.



As noticed by Linus, it is critical that some of the
rwsem constants be signed.  Yet, hex constants are
unsigned unless explicitly casted or negated.

The most critical one is RWSEM_WAITING_BIAS.

This bug was exacerbated by commit
424acaae ("rwsem: wake queued readers
when writer blocks on active read lock")

Signed-off-by: David S. Miller <davem@davemloft.net>

parent 8e8073a4

arch/sparc/include/asm/rwsem-const.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -5,7 +5,7 @@
		#define RWSEM_UNLOCKED_VALUE 0x00000000
		#define RWSEM_ACTIVE_BIAS 0x00000001
		#define RWSEM_ACTIVE_MASK 0x0000ffff
		#define RWSEM_WAITING_BIAS 0xffff0000
		#define RWSEM_WAITING_BIAS (-0x00010000)
		#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
		#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)