[PATCH 5.15 081/128] parisc: Fix mask used to select futex spinlock

Greg Kroah-Hartman
2021-12-27T15:51:56Z

From: John David Anglin <dave.anglin@bell.net>

commit d3a5a68cff47f6eead84504c3c28376b85053242 upstream.

The address bits used to select the futex spinlock need to match those used in
the LWS code in syscall.S. The mask 0x3f8 only selects 7 bits. It should
select 8 bits.

This change fixes the glibc nptl/tst-cond24 and nptl/tst-cond25 tests.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Fixes: 53a42b6324b8 ("parisc: Switch to more fine grained lws locks")
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/parisc/include/asm/futex.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/parisc/include/asm/futex.h
+++ b/arch/parisc/include/asm/futex.h
@@ -16,7 +16,7 @@ static inline void
_futex_spin_lock_irqsave(u32 __user *uaddr, unsigned long int *flags)
{
extern u32 lws_lock_start[];
- long index = ((long)uaddr & 0x3f8) >> 1;
+ long index = ((long)uaddr & 0x7f8) >> 1;
arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
local_irq_save(*flags);
arch_spin_lock(s);
@@ -26,7 +26,7 @@ static inline void
_futex_spin_unlock_irqrestore(u32 __user *uaddr, unsigned long int *flags)
{
extern u32 lws_lock_start[];
- long index = ((long)uaddr & 0x3f8) >> 1;
+ long index = ((long)uaddr & 0x7f8) >> 1;
arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
arch_spin_unlock(s);
local_irq_restore(*flags);