uml: fix stub address calculations

The calculation of CONFIG_STUB_CODE and CONFIG_STUB_DATA didn't take into
account anything but 3G/1G and 2G/2G, leaving the other vmsplits out in the
cold.

I'd rather not duplicate the four known host vmsplit cases for each of these
symbols.  I'd also like to calculate them based on the highest userspace
address.

The Kconfig language seems not to allow calculation of hex constants, so I
moved this to as-layout.h.  CONFIG_STUB_CODE, CONFIG_STUB_DATA, and
CONFIG_STUB_START are now gone.  In their place are STUB_CODE, STUB_DATA, and
STUB_START in as-layout.h.

i386 and x86_64 seem to differ as to whether an unadorned constant is an int
or a long, so I cast them to unsigned long so they can be printed
consistently.  However, they are also used in stub.S, where C types don't work
so well.  So, there are ASM_ versions of these constants for use in stub.S.  I
also ifdef-ed the non-asm-friendly portion of as-layout.h.

With this in place, most of the rest of this patch is changing CONFIG_STUB_*
to STUB_*, except in stub.S, where they are changed to ASM_STUB_*.

defconfig has the old symbols deleted.

I also print these addresses out in case there is any problem mapping them on
the host.

The two stub.S files had some trailing whitespace, so that is cleaned up here.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 7 insertions, 5 deletions

diff --git a/arch/um/sys-x86_64/stub.S b/arch/um/sys-x86_64/stub.S
index 03c279735784..4afe204a6af7 100644
--- a/arch/um/sys-x86_64/stub.S
+++ b/arch/um/sys-x86_64/stub.S
@@ -1,4 +1,5 @@
 #include "uml-config.h"
+#include "as-layout.h"
 
         .globl syscall_stub
 .section .__syscall_stub, "x"
@@ -7,18 +8,18 @@ syscall_stub:
         /* We don't have 64-bit constants, so this constructs the address
          * we need.
          */
-        movq    $(UML_CONFIG_STUB_DATA >> 32), %rbx
+        movq    $(ASM_STUB_DATA >> 32), %rbx
         salq    $32, %rbx
-        movq    $(UML_CONFIG_STUB_DATA & 0xffffffff), %rcx
+        movq    $(ASM_STUB_DATA & 0xffffffff), %rcx
         or      %rcx, %rbx
         movq    %rax, (%rbx)
         int3
 
         .globl batch_syscall_stub
 batch_syscall_stub:
-        mov     $(UML_CONFIG_STUB_DATA >> 32), %rbx
+        mov     $(ASM_STUB_DATA >> 32), %rbx
         sal     $32, %rbx
-        mov     $(UML_CONFIG_STUB_DATA & 0xffffffff), %rax
+        mov     $(ASM_STUB_DATA & 0xffffffff), %rax
         or      %rax, %rbx
         /* load pointer to first operation */
         mov     %rbx, %rsp
diff --git a/arch/um/sys-x86_64/stub_segv.c b/arch/um/sys-x86_64/stub_segv.c
index 652fa34c2cd3..3afb590f0072 100644
--- a/arch/um/sys-x86_64/stub_segv.c
+++ b/arch/um/sys-x86_64/stub_segv.c
@@ -6,6 +6,7 @@
 #include <stddef.h>
 #include <signal.h>
 #include <asm/unistd.h>
+#include "as-layout.h"
 #include "uml-config.h"
 #include "sysdep/sigcontext.h"
 #include "sysdep/faultinfo.h"
@@ -33,7 +34,7 @@ stub_segv_handler(int sig)
         int pid;
 
         __asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :);
-        GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
+        GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA),
                               &uc->uc_mcontext);
 
         pid = stub_syscall0(__NR_getpid);