Changeset 0871296 in mainline for kernel/arch/ppc32/src/exception.S

Timestamp:

2014-08-28T13:59:43Z (10 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

3fde837

Parents:

beb16cfa

Message:

Base the detection of the previous mode on SRR1.PR rather than on SP.

File:

• kernel/arch/ppc32/src/exception.S (modified) (3 diffs)

kernel/arch/ppc32/src/exception.S

@@ -31 +31 @@
 #include <arch/mm/page.h>
 #include <arch/istate_struct.h>
+#include <arch/stack.h>
 #include <align.h>
-#include <arch/stack.h>
 
 .section K_UNMAPPED_TEXT_START, "ax"
@@ -45 +45 @@
         mtsprg2 sp
         
-        # check whether SP is in kernel
-        
-        andis. sp, sp, 0x8000
+        # check whether the previous mode was user or kernel
+        
+        mfsrr1 sp # use sp as a temporary register to hold SRR1
+        andi. sp, sp, MSR_PR 
         bne 1f
-        
-                # stack is in user-space
-                
-                mfsprg0 sp
-        
-        b 2f
-        
-        1:
-        
-                # stack is in kernel
+                # previous mode was kernel
                 
                 mfsprg2 sp
                 subis sp, sp, 0x8000
-        
+        b 2f
+        
+        1:
+                # previous mode was user
+                
+                mfsprg0 sp
         2:
         
@@ -266 +263 @@
         
         mfsrr1 r5
+
+        andi. r5, r5, MSR_PR
+
         andi. r5, r5, MSR_FP
         mfmsr r12