Changeset 11376

Timestamp:

Nov 17, 2008, 3:06:10 AM (12 years ago)

Author:

gb

Message:

On FreeBSD, whether or not we can write to rcontext depends on whether
or not the 32-bit lisp is running on a 64-bit kernel, so check
'rcontext_readonly' and skip loading rcontext from the tcr if it's
non-zero. (On a 32-bit kernel, %fs can get clobbered sometimes.)

Location:

trunk/source/lisp-kernel

Files:

• x86-spentry32.s (modified) (1 diff)
• x86-subprims32.s (modified) (1 diff)

trunk/source/lisp-kernel/x86-spentry32.s

@@ -4263 +4263 @@
         __(push %ebp)
         __(box_fixnum(%eax,%esi))       /* put callback index in arg_y */
-        __ifndef([FREEBSD])
-         __(ref_global(get_tcr,%eax))
-         __(subl $12,%esp)              /* alignment */
-         __(push $1)                    /* stack now 16-byte aligned */
-         __(call *%eax)
-         __(addl $16,%esp)              /* discard arg, alignment words */
-         /* linear TCR addr now in %eax */
-         __(movw tcr.ldt_selector(%eax), %rcontext_reg)
-        __endif
+        __(cmpb $0,C(rcontext_readonly))
+        __(jne 0f)
+        __(ref_global(get_tcr,%eax))
+        __(subl $12,%esp)               /* alignment */
+        __(push $1)                     /* stack now 16-byte aligned */
+        __(call *%eax)
+        __(addl $16,%esp)               /* discard arg, alignment words */
+        /* linear TCR addr now in %eax */
+        __(movw tcr.ldt_selector(%eax), %rcontext_reg)
+0:      
 
         /* ebp is 16-byte aligned, and we've pushed 4 words.  Make

trunk/source/lisp-kernel/x86-subprims32.s

@@ -75 +75 @@
         __(push %ebx)
         __(mov 8(%ebp), %ebx)   /* get tcr */
-        __ifndef([FREEBSD])
-         __(movw tcr.ldt_selector(%ebx), %rcontext_reg)
-        __endif
+        __(cmpb $0,C(rcontext_readonly))
+        __(jne 0f)
+        __(movw tcr.ldt_selector(%ebx), %rcontext_reg)
+0:              
         __(movl 8(%ebp),%eax)
         __(cmpl rcontext(tcr.linear),%eax)
-        __(je 0f)
+        __(je 1f)
         __(hlt)
-0:              
+1:              
         .if c_stack_16_byte_aligned
         __(sub $12, %esp)       /* stack now 16-byte aligned */