alpha: strncpy/strncat fixes

First of all, thanks to Bob Tracy <rct@frus.com> and
Michael Cree <mcree@orcon.net.nz> for testing.
Especially to Bob, as he has done titanic multi-day git-bisect
work that finally helped to reproduce and nail down the bug
(http://bugzilla.kernel.org/show_bug.cgi?id=9457).

[ev6-]stxncpy.S: it's t12, not t2 register that is supposed to contain
the last byte offset upon return. As a result of wrong register use
(which was my fault back in 2003, IIRC), under some circumstances extra
terminating zero bytes were added to destination string. This particularly
led to incorrect DEVPATH strings generated in uevent and therefore to udev
problems.

strncpy.S: unrelated bug I found while testing the above fix - destination
is not properly zero-padded then a byte count exceeds source length.
Actually this is addition to strncpy fix from last year.

Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Bob Tracy <rct@frus.com>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 15 insertions, 15 deletions

diff --git a/arch/alpha/lib/ev6-stxncpy.S b/arch/alpha/lib/ev6-stxncpy.S
index b581a7af2456..1aa6e97e04b5 100644
--- a/arch/alpha/lib/ev6-stxncpy.S
+++ b/arch/alpha/lib/ev6-stxncpy.S
@@ -362,10 +362,10 @@ $unaligned:
 
         extql   t2, a1, t2      # U :
         cmpbge  zero, t1, t8    # E : is there a zero?
-        andnot  t2, t6, t12     # E : dest mask for a single word copy
+        andnot  t2, t6, t2      # E : dest mask for a single word copy
         or      t8, t10, t5     # E : test for end-of-count too
 
-        cmpbge  zero, t12, t3   # E :
+        cmpbge  zero, t2, t3    # E :
         cmoveq  a2, t5, t8      # E : Latency=2, extra map slot
         nop                     # E : keep with cmoveq
         andnot  t8, t3, t8      # E : (stall)
@@ -379,13 +379,13 @@ $unaligned:
         negq    t8, t6          # E : build bitmask of bytes <= zero
         mskqh   t1, t4, t1      # U :
 
-        and     t6, t8, t2      # E :
-        subq    t2, 1, t6       # E : (stall)
-        or      t6, t2, t8      # E : (stall)
-        zapnot  t12, t8, t12    # U : prepare source word; mirror changes (stall)
+        and     t6, t8, t12     # E :
+        subq    t12, 1, t6      # E : (stall)
+        or      t6, t12, t8     # E : (stall)
+        zapnot  t2, t8, t2      # U : prepare source word; mirror changes (stall)
 
         zapnot  t1, t8, t1      # U : to source validity mask
-        andnot  t0, t12, t0     # E : zero place for source to reside
+        andnot  t0, t2, t0      # E : zero place for source to reside
         or      t0, t1, t0      # E : and put it there (stall both t0, t1)
         stq_u   t0, 0(a0)       # L : (stall)
 
diff --git a/arch/alpha/lib/strncpy.S b/arch/alpha/lib/strncpy.S
index bbdef1be5f95..a46f7f3ad8c7 100644
--- a/arch/alpha/lib/strncpy.S
+++ b/arch/alpha/lib/strncpy.S
@@ -35,7 +35,7 @@ strncpy:
 
         or      $3, $24, $3     # clear the bits between the last
         or      $4, $27, $4     # written byte and the last byte in COUNT
-        andnot  $4, $3, $4
+        andnot  $3, $4, $4
         zap     $1, $4, $1
 
         stq_u   $1, 0($16)
diff --git a/arch/alpha/lib/stxncpy.S b/arch/alpha/lib/stxncpy.S
index da1a72740d29..3dece25283a3 100644
--- a/arch/alpha/lib/stxncpy.S
+++ b/arch/alpha/lib/stxncpy.S
@@ -315,9 +315,9 @@ $unaligned:
 
         extql   t2, a1, t2      # e0    :
         cmpbge  zero, t1, t8    # .. e1 : is there a zero?
-        andnot  t2, t6, t12     # e0    : dest mask for a single word copy
+        andnot  t2, t6, t2      # e0    : dest mask for a single word copy
         or      t8, t10, t5     # .. e1 : test for end-of-count too
-        cmpbge  zero, t12, t3   # e0    :
+        cmpbge  zero, t2, t3    # e0    :
         cmoveq  a2, t5, t8      # .. e1 :
         andnot  t8, t3, t8      # e0    :
         beq     t8, $u_head     # .. e1 (zdb)
@@ -330,14 +330,14 @@ $unaligned:
         ldq_u   t0, 0(a0)       # e0    :
         negq    t8, t6          # .. e1 : build bitmask of bytes <= zero
         mskqh   t1, t4, t1      # e0    :
-        and     t6, t8, t2      # .. e1 :
-        subq    t2, 1, t6       # e0    :
-        or      t6, t2, t8      # e1    :
+        and     t6, t8, t12     # .. e1 :
+        subq    t12, 1, t6      # e0    :
+        or      t6, t12, t8     # e1    :
 
-        zapnot  t12, t8, t12    # e0    : prepare source word; mirror changes
+        zapnot  t2, t8, t2      # e0    : prepare source word; mirror changes
         zapnot  t1, t8, t1      # .. e1 : to source validity mask
 
-        andnot  t0, t12, t0     # e0    : zero place for source to reside
+        andnot  t0, t2, t0      # e0    : zero place for source to reside
         or      t0, t1, t0      # e1    : and put it there
         stq_u   t0, 0(a0)       # e0    :
         ret     (t9)            # .. e1 :