parisc: Fix extraction of hash lock bits in syscall.S

The extru instruction leaves the most significant 32 bits of the target
register in an undefined state on PA 2.0 systems. If any of these bits
are nonzero, this will break the calculation of the lock pointer.

Fix by using extrd,u instruction via extru_safe macro on 64-bit kernels.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index 4fb3b6a..d2497b3 100644 (file)
--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -566,7 +566,7 @@ lws_compare_and_swap:
        ldo     R%lws_lock_start(%r20), %r28
 
        /* Extract eight bits from r26 and hash lock (Bits 3-11) */
-       extru  %r26, 28, 8, %r20
+       extru_safe  %r26, 28, 8, %r20
 
        /* Find lock to use, the hash is either one of 0 to
           15, multiplied by 16 (keep it 16-byte aligned)
@@ -751,7 +751,7 @@ cas2_lock_start:
        ldo     R%lws_lock_start(%r20), %r28
 
        /* Extract eight bits from r26 and hash lock (Bits 3-11) */
-       extru  %r26, 28, 8, %r20
+       extru_safe  %r26, 28, 8, %r20
 
        /* Find lock to use, the hash is either one of 0 to
           15, multiplied by 16 (keep it 16-byte aligned)