3 files changed, 29 insertions, 21 deletions

diff --git a/arch/um/include/as-layout.h b/arch/um/include/as-layout.h
index a5cdf953e04a..2b859e020ac6 100644
--- a/arch/um/include/as-layout.h
+++ b/arch/um/include/as-layout.h
@@ -10,23 +10,31 @@
 #include "kern_constants.h"
 
 /*
- * Assembly doesn't want any casting, but C does, so define these
- * without casts here, and define new symbols with casts inside the C
- * section.
+ * Stolen from linux/const.h, which can't be directly included since
+ * this is used in userspace code, which has no access to the kernel
+ * headers.  Changed to be suitable for adding casts to the start,
+ * rather than "UL" to the end.
  */
-#define ASM_STUB_CODE (UML_CONFIG_TOP_ADDR - 2 * UM_KERN_PAGE_SIZE)
-#define ASM_STUB_DATA (UML_CONFIG_TOP_ADDR - UM_KERN_PAGE_SIZE)
-#define ASM_STUB_START ASM_STUB_CODE
 
-/*
- * This file is included by the assembly stubs, which just want the
- * definitions above.
+/* Some constant macros are used in both assembler and
+ * C code.  Therefore we cannot annotate them always with
+ * 'UL' and other type specifiers unilaterally.  We
+ * use the following macros to deal with this.
  */
-#ifndef __ASSEMBLY__
 
-#define STUB_CODE ((unsigned long) ASM_STUB_CODE)
-#define STUB_DATA ((unsigned long) ASM_STUB_DATA)
-#define STUB_START ((unsigned long) ASM_STUB_START)
+#ifdef __ASSEMBLY__
+#define _AC(X, Y)       (Y)
+#else
+#define __AC(X, Y)      (X (Y))
+#define _AC(X, Y)       __AC(X, Y)
+#endif
+
+#define STUB_CODE _AC((unsigned long), \
+                      UML_CONFIG_TOP_ADDR - 2 * UM_KERN_PAGE_SIZE)
+#define STUB_DATA _AC((unsigned long), UML_CONFIG_TOP_ADDR - UM_KERN_PAGE_SIZE)
+#define STUB_START _AC(, STUB_CODE)
+
+#ifndef __ASSEMBLY__
 
 #include "sysdep/ptrace.h"
 
diff --git a/arch/um/sys-i386/stub.S b/arch/um/sys-i386/stub.S
index e730772c401b..7699e89f660f 100644
--- a/arch/um/sys-i386/stub.S
+++ b/arch/um/sys-i386/stub.S
@@ -7,7 +7,7 @@
         .globl batch_syscall_stub
 batch_syscall_stub:
         /* load pointer to first operation */
-        mov     $(ASM_STUB_DATA+8), %esp
+        mov     $(STUB_DATA+8), %esp
 
 again:
         /* load length of additional data */
@@ -15,12 +15,12 @@ again:
 
         /* if(length == 0) : end of list */
         /* write possible 0 to header */
-        mov     %eax, ASM_STUB_DATA+4
+        mov     %eax, STUB_DATA+4
         cmpl    $0, %eax
         jz      done
 
         /* save current pointer */
-        mov     %esp, ASM_STUB_DATA+4
+        mov     %esp, STUB_DATA+4
 
         /* skip additional data */
         add     %eax, %esp
@@ -46,7 +46,7 @@ again:
 
 done:
         /* save return value */
-        mov     %eax, ASM_STUB_DATA
+        mov     %eax, STUB_DATA
 
         /* stop */
         int3
diff --git a/arch/um/sys-x86_64/stub.S b/arch/um/sys-x86_64/stub.S
index 4afe204a6af7..568768763155 100644
--- a/arch/um/sys-x86_64/stub.S
+++ b/arch/um/sys-x86_64/stub.S
@@ -8,18 +8,18 @@ syscall_stub:
         /* We don't have 64-bit constants, so this constructs the address
          * we need.
          */
-        movq    $(ASM_STUB_DATA >> 32), %rbx
+        movq    $(STUB_DATA >> 32), %rbx
         salq    $32, %rbx
-        movq    $(ASM_STUB_DATA & 0xffffffff), %rcx
+        movq    $(STUB_DATA & 0xffffffff), %rcx
         or      %rcx, %rbx
         movq    %rax, (%rbx)
         int3
 
         .globl batch_syscall_stub
 batch_syscall_stub:
-        mov     $(ASM_STUB_DATA >> 32), %rbx
+        mov     $(STUB_DATA >> 32), %rbx
         sal     $32, %rbx
-        mov     $(ASM_STUB_DATA & 0xffffffff), %rax
+        mov     $(STUB_DATA & 0xffffffff), %rax
         or      %rax, %rbx
         /* load pointer to first operation */
         mov     %rbx, %rsp