libc - fix mcontext issues

* Fix incorrect register use in _get_mcontext() left over from the
  32-bit port to 64-bits.

* This routine is only (currently) used by a few pkgsrc packages.

diff --git a/lib/libc/x86_64/gen/mcontext.S b/lib/libc/x86_64/gen/mcontext.S
index ea31674..a86889e 100644 (file)
--- a/lib/libc/x86_64/gen/mcontext.S
+++ b/lib/libc/x86_64/gen/mcontext.S
@@ -32,7 +32,7 @@
        /*
         * int get_mcontext(mcontext_t *mcp : rdi)
         *
-        * Copy the caller's context into the mcontext, %eax excepted.
+        * Copy the caller's context into the mcontext, %rax excepted.
         */
         .weak   get_mcontext
         .set    get_mcontext,_get_mcontext
@@ -66,11 +66,11 @@ ENTRY(_get_mcontext)
         * Saved stack pointer as if we had returned from this
         * procedure.
         */
-       movq    %rsp,MC_RSP(%eax)
-       addq    $8,MC_RSP(%eax)
+       movq    %rsp,MC_RSP(%rdi)
+       addq    $8,MC_RSP(%rdi)
 
        /*
-        * Save eflags
+        * Save rflags
         * XXX
         */
 
@@ -89,7 +89,7 @@ ENTRY(_get_mcontext)
        /*
         * Set MC_LEN
         */
-       movl    $SIZEOF_MCONTEXT_T,MC_LEN(%eax)
+       movl    $SIZEOF_MCONTEXT_T,MC_LEN(%rdi)
 
        /*
         * Return 0