xnu-4903.270.47.tar.gz

[apple/xnu.git] / osfmk / x86_64 / cswitch.s

diff --git a/osfmk/x86_64/cswitch.s b/osfmk/x86_64/cswitch.s
index 88d88060c80540bf6c941c208bfac32ae7da99e7..cb72f459e30f897538cb9abbfde84d929f6e18c5 100644 (file)
--- a/osfmk/x86_64/cswitch.s
+++ b/osfmk/x86_64/cswitch.s
@@ -69,9 +69,9 @@ Entry(Load_context)
        movq    %rdx,%gs:CPU_KERNEL_STACK       /* store stack top */
 
        movq    %rdx,%rsp
-       movq    %rdx,%rbp
+       xorl    %ebp, %ebp
 
-       xorq    %rdi,%rdi                       /* return zero (no old thread) */
+       xorl    %edi,%edi                       /* return zero (no old thread) */
        call    EXT(thread_continue)
 
 
@@ -118,7 +118,7 @@ Entry(Switch_context)
 
 
 Entry(Thread_continue)
-       movq    %rax, %rdi                      /* load thread argument */
+       movq    %rax, %rdi                      /* this is the old thread from Switch_context */
        xorq    %rbp,%rbp                       /* zero frame pointer */
        call    *%rbx                           /* call real continuation */
 
@@ -152,6 +152,9 @@ Entry(Shutdown_context)
 
        movq    %gs:CPU_INT_STACK_TOP,%rsp      /* switch to interrupt stack */
 
+       movq    %rsp, %gs:CPU_ACTIVE_STACK
+       movq    EXT(kernel_stack_size)(%rip),%rcx /* point to stack top */
+       subq    %rcx, %gs:CPU_ACTIVE_STACK
        movq    %rdx,%rdi                       /* processor arg to routine */
        call    *%rsi                           /* call routine to run */
        hlt                                     /* (should never return) */