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Subject[50/91] sparc64: Fix rwsem constant bug leading to hangs.
2.6.34-stable review patch.  If anyone has any objections, please let us know.


From: David S. Miller <>

[ Upstream commit ef201bebe5afc91a2b99b45dacc8c6dd88ca9e58 ]

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
424acaaeb3a3932d64a9b4bd59df6cf72c22d8f3 ("rwsem: wake queued readers
when writer blocks on active read lock")

Signed-off-by: David S. Miller <>
Signed-off-by: Greg Kroah-Hartman <>
arch/sparc/include/asm/rwsem-const.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/sparc/include/asm/rwsem-const.h
+++ b/arch/sparc/include/asm/rwsem-const.h
@@ -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)

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