svn commit: r285620 - head/sys/powerpc/aim

[Justin Hibbits]

Author: jhibbits
Date: Thu Jul 16 05:13:08 2015
New Revision: 285620
URL: https://svnweb.freebsd.org/changeset/base/285620

Log:
  Fix userland program exception handling for powerpc64.
  
  It appears that the linker will not handle 64-bit relocations at addresses that
  are not aligned to 8-byte boundaries.  Prior to this change the line:
  
    .llong generictrap
  
  was aligned to a 4-byte address, and the linker replaced that with an 8-byte
  0x0.  Aligning that address to 8 bytes caused the linker to generate the proper
  relocation.  As a follow-through, the dblow from trap_subr33.S used the code
  sequence 'lwz %r1, TRAP_GENTRAP(0)', so this reproduces the analogue of that for
  64-bit.

Modified:
  head/sys/powerpc/aim/trap_subr64.S

Modified: head/sys/powerpc/aim/trap_subr64.S
==============================================================================
--- head/sys/powerpc/aim/trap_subr64.S	Thu Jul 16 04:15:22 2015	(r285619)
+++ head/sys/powerpc/aim/trap_subr64.S	Thu Jul 16 05:13:08 2015	(r285620)
@@ -842,11 +842,7 @@ CNAME(dblow):
         mflr	%r1			/* save LR */
 	mtsprg2 %r1			/* And then in SPRG2 */
 
-	nop				/* Begin branching to generictrap */
-	bl	9f
-	.llong	generictrap
-9:	mflr	%r1
-	ld	%r1,0(%r1)
+	ld	%r1, TRAP_GENTRAP(0)	/* Get branch address */
 	mtlr	%r1
 	li	%r1, 0	 		/* How to get the vector from LR */
 	blrl				/* Branch to generictrap */