[Sbcl-commits] master: Fix allocating nil-vectors on ARM.

[stassats <sta...@us...>]

The branch "master" has been updated in SBCL:
       via  7eee005059222fae4c40984b3c44962381c2b0ab (commit)
      from  d5e780dee9bcc5127c747df90660a675fb1fcf69 (commit)

- Log -----------------------------------------------------------------
commit 7eee005059222fae4c40984b3c44962381c2b0ab
Author: Stas Boukarev <sta...@gm...>
Date:   Wed May 14 00:01:50 2014 +0400

    Fix allocating nil-vectors on ARM.
    
    The recent change caused overwriting of the length header for
    nil-vectors.
---
 src/assembly/arm/array.lisp |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/assembly/arm/array.lisp b/src/assembly/arm/array.lisp
index a2ddb21..2facb9e 100644
--- a/src/assembly/arm/array.lisp
+++ b/src/assembly/arm/array.lisp
@@ -33,11 +33,13 @@
     (allocation vector ndescr other-pointer-lowtag :flag-tn pa-flag)
     (inst mov ndescr (lsr type word-shift))
     (storew ndescr vector 0 other-pointer-lowtag)
-    (storew length vector vector-length-slot other-pointer-lowtag)
     ;; Touch the last element, to ensure that null-terminated strings
     ;; passed to C do not cause a WP violation in foreign code.
+    ;; Do that before storing length, since nil-arrays don't have any
+    ;; space, but may have non-zero length.
     #!-gencgc
     (inst mov ndescr 0)
     #!-gencgc
-    (storew ndescr pa-flag -1))
+    (storew ndescr pa-flag -1)
+    (storew length vector vector-length-slot other-pointer-lowtag))
   (move result vector))

-----------------------------------------------------------------------


hooks/post-receive
-- 
SBCL