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, 6 deletions

diff --git a/arch/um/sys-i386/stub.S b/arch/um/sys-i386/stub.S
index 6a70d9a..e730772 100644
--- a/arch/um/sys-i386/stub.S
+++ b/arch/um/sys-i386/stub.S
@@ -1,4 +1,5 @@
 #include "uml-config.h"
+#include "as-layout.h"
 
 	.globl syscall_stub
 .section .__syscall_stub, "x"
@@ -6,7 +7,7 @@
 	.globl batch_syscall_stub
 batch_syscall_stub:
 	/* load pointer to first operation */
-	mov	$(UML_CONFIG_STUB_DATA+8), %esp
+	mov	$(ASM_STUB_DATA+8), %esp
 
 again:
 	/* load length of additional data */
@@ -14,12 +15,12 @@ again:
 
 	/* if(length == 0) : end of list */
 	/* write possible 0 to header */
-	mov	%eax, UML_CONFIG_STUB_DATA+4
+	mov	%eax, ASM_STUB_DATA+4
 	cmpl	$0, %eax
 	jz	done
 
 	/* save current pointer */
-	mov	%esp, UML_CONFIG_STUB_DATA+4
+	mov	%esp, ASM_STUB_DATA+4
 
 	/* skip additional data */
 	add	%eax, %esp
@@ -45,7 +46,7 @@ again:
 
 done:
 	/* save return value */
-	mov	%eax, UML_CONFIG_STUB_DATA
+	mov	%eax, ASM_STUB_DATA
 
 	/* stop */
 	int3
diff --git a/arch/um/sys-i386/stub_segv.c b/arch/um/sys-i386/stub_segv.c
index 2355dc1..b3999cb 100644
--- a/arch/um/sys-i386/stub_segv.c
+++ b/arch/um/sys-i386/stub_segv.c
@@ -6,6 +6,7 @@
 #include <signal.h>
 #include <sys/select.h> /* The only way I can see to get sigset_t */
 #include <asm/unistd.h>
+#include "as-layout.h"
 #include "uml-config.h"
 #include "sysdep/stub.h"
 #include "sysdep/sigcontext.h"
@@ -17,8 +18,7 @@ stub_segv_handler(int sig)
 	struct sigcontext *sc = (struct sigcontext *) (&sig + 1);
 	int pid;
 
-	GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
-			      sc);
+	GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA), sc);
 
 	pid = stub_syscall0(__NR_getpid);
 	stub_syscall2(__NR_kill, pid, SIGUSR1);