add copyoutstr to speed up exec

SCCS-vsn: sys/vax/vax/locore.s 6.10

diff --git a/usr/src/sys/vax/vax/locore.s b/usr/src/sys/vax/vax/locore.s
index 4c14992..3151c9d 100644 (file)
--- a/usr/src/sys/vax/vax/locore.s
+++ b/usr/src/sys/vax/vax/locore.s
@@ -1,4 +1,4 @@
-/*     locore.s        6.9     84/07/08        */
+/*     locore.s        6.10    84/07/27        */

 
 #include "../machine/psl.h"
 #include "../machine/pte.h"
 
 #include "../machine/psl.h"
 #include "../machine/pte.h"


@@ -803,6 +803,39 @@ _copyinstr:
 1:
        ret
 
 1:
        ret
 

+/*
+ * Copy a null terminated string from the kernel
+ * address space to the user address space.
+ *
+ * copyoutstr(fromaddr, toaddr, maxlength, &lencopied)
+ */
+       .globl  _copyoutstr
+_copyoutstr:
+       .word   0x40                    # save r6
+       movl    12(ap),r6               # r6 = max length
+       jlss    8b
+       movl    4(ap),r1                # r1 = kernel address
+       movl    8(ap),r3                # r3 = user address
+       bicl3   $~(NBPG-1),r3,r2        # r2 = bytes on first page
+       subl3   r2,$NBPG,r2
+1:
+       cmpl    r6,r2                   # r2 = min(bytes on page, length left);
+       jgeq    2f
+       movl    r6,r2
+2:
+       probew  $3,r2,(r3)              # bytes accessible?
+       jeql    8b
+       subl2   r2,r6                   # update bytes left count
+       locc    $0,r2,(r1)              # null byte found?
+       jneq    3b
+       subl2   r2,r1                   # back up pointer updated by `locc'
+       movc3   r2,(r1),(r3)            # copy in next piece
+       movl    $NBPG,r2                # check next page
+       tstl    r6                      # run out of space?
+       jneq    1b
+       movl    $ENOENT,r0              # set error code and return
+       jbr     9b
+

 /*
  * Copy a null terminated string from one point to another in
  * the kernel address space.
 /*
  * Copy a null terminated string from one point to another in
  * the kernel address space.