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>

6 files changed, 14 insertions, 11 deletions

diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index 7c77adecd919..8196450451cd 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -11,6 +11,7 @@
 #include "asm/current.h"
 #include "asm/processor.h"
 #include "asm/uaccess.h"
+#include "as-layout.h"
 #include "mem_user.h"
 #include "skas.h"
 #include "os.h"
@@ -18,7 +19,7 @@
 void flush_thread(void)
 {
         void *data = NULL;
-        unsigned long end = proc_mm ? task_size : CONFIG_STUB_START;
+        unsigned long end = proc_mm ? task_size : STUB_START;
         int ret;
 
         arch_flush_thread(&current->thread.arch);
diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c
index 47b812b3bca8..d119f4f7d897 100644
--- a/arch/um/kernel/skas/clone.c
+++ b/arch/um/kernel/skas/clone.c
@@ -4,6 +4,7 @@
 #include <sys/time.h>
 #include <asm/unistd.h>
 #include <asm/page.h>
+#include "as-layout.h"
 #include "ptrace_user.h"
 #include "skas.h"
 #include "stub-data.h"
@@ -21,12 +22,11 @@
 void __attribute__ ((__section__ (".__syscall_stub")))
 stub_clone_handler(void)
 {
-        struct stub_data *data = (struct stub_data *) UML_CONFIG_STUB_DATA;
+        struct stub_data *data = (struct stub_data *) STUB_DATA;
         long err;
 
         err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
-                            UML_CONFIG_STUB_DATA + UM_KERN_PAGE_SIZE / 2 -
-                            sizeof(void *));
+                            STUB_DATA + UM_KERN_PAGE_SIZE / 2 - sizeof(void *));
         if(err != 0)
                 goto out;
 
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index ae79888cf520..f859ec306cd5 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -7,6 +7,7 @@
 #include "linux/sched.h"
 #include "asm/pgalloc.h"
 #include "asm/pgtable.h"
+#include "as-layout.h"
 #include "os.h"
 #include "skas.h"
 
@@ -83,12 +84,12 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
                  */
                 mm->pgd[USER_PTRS_PER_PGD] = __pgd(0);
 
-                ret = init_stub_pte(mm, CONFIG_STUB_CODE,
+                ret = init_stub_pte(mm, STUB_CODE,
                                     (unsigned long) &__syscall_stub_start);
                 if (ret)
                         goto out_free;
 
-                ret = init_stub_pte(mm, CONFIG_STUB_DATA, stack);
+                ret = init_stub_pte(mm, STUB_DATA, stack);
                 if (ret)
                         goto out_free;
 
diff --git a/arch/um/kernel/skas/process.c b/arch/um/kernel/skas/process.c
index 0297e63f9725..fce389c2342f 100644
--- a/arch/um/kernel/skas/process.c
+++ b/arch/um/kernel/skas/process.c
@@ -18,7 +18,7 @@ int new_mm(unsigned long stack)
                 return fd;
 
         if (skas_needs_stub)
-                map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
+                map_stub_pages(fd, STUB_CODE, STUB_DATA, stack);
 
         return fd;
 }
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 942f20ea888a..f4a0e407eee4 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -485,8 +485,8 @@ void __flush_tlb_one(unsigned long addr)
 static void fix_range(struct mm_struct *mm, unsigned long start_addr,
                       unsigned long end_addr, int force)
 {
-        if (!proc_mm && (end_addr > CONFIG_STUB_START))
-                end_addr = CONFIG_STUB_START;
+        if (!proc_mm && (end_addr > STUB_START))
+                end_addr = STUB_START;
 
         fix_range_common(mm, start_addr, end_addr, force);
 }
@@ -510,7 +510,7 @@ void flush_tlb_mm(struct mm_struct *mm)
         if (atomic_read(&mm->mm_users) == 0)
                 return;
 
-        end = proc_mm ? task_size : CONFIG_STUB_START;
+        end = proc_mm ? task_size : STUB_START;
         fix_range(mm, 0, end, 0);
 }
 
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 1993e5e12256..f1c71393f578 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -242,7 +242,8 @@ static unsigned long set_task_sizes_skas(unsigned long *task_size_out)
 
         if (!skas_needs_stub)
                 *task_size_out = host_task_size;
-        else *task_size_out = CONFIG_STUB_START & PGDIR_MASK;
+        else
+                *task_size_out = STUB_START & PGDIR_MASK;
 
         return host_task_size;
 }