8 files changed, 28 insertions, 34 deletions

diff --git a/arch/um/include/skas/mode_kern_skas.h b/arch/um/include/skas/mode_kern_skas.h
index 651350adfe03..9cd9c6ec9a63 100644
--- a/arch/um/include/skas/mode_kern_skas.h
+++ b/arch/um/include/skas/mode_kern_skas.h
@@ -29,8 +29,7 @@ extern void flush_tlb_mm_skas(struct mm_struct *mm);
 extern void force_flush_all_skas(void);
 extern long execute_syscall_skas(void *r);
 extern void before_mem_skas(unsigned long unused);
-extern unsigned long set_task_sizes_skas(unsigned long *host_size_out,
-                                         unsigned long *task_size_out);
+extern unsigned long set_task_sizes_skas(unsigned long *task_size_out);
 extern int start_uml_skas(void);
 extern int external_pid_skas(struct task_struct *task);
 extern int thread_pid_skas(struct task_struct *task);
diff --git a/arch/um/include/tt/mode_kern_tt.h b/arch/um/include/tt/mode_kern_tt.h
index fb2d3d76685a..a4fc63057195 100644
--- a/arch/um/include/tt/mode_kern_tt.h
+++ b/arch/um/include/tt/mode_kern_tt.h
@@ -30,8 +30,7 @@ extern void flush_tlb_mm_tt(struct mm_struct *mm);
 extern void force_flush_all_tt(void);
 extern long execute_syscall_tt(void *r);
 extern void before_mem_tt(unsigned long brk_start);
-extern unsigned long set_task_sizes_tt(unsigned long *host_size_out,
-                                       unsigned long *task_size_out);
+extern unsigned long set_task_sizes_tt(unsigned long *task_size_out);
 extern int start_uml_tt(void);
 extern int external_pid_tt(struct task_struct *task);
 extern int thread_pid_tt(struct task_struct *task);
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 44e41a35f000..61280167c560 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -24,8 +24,6 @@
 #include "init.h"
 #include "kern_constants.h"
 
-extern char __binary_start;
-
 /* Changed during early boot */
 unsigned long *empty_zero_page = NULL;
 unsigned long *empty_bad_page = NULL;
@@ -65,8 +63,6 @@ static void setup_highmem(unsigned long highmem_start,
 
 void mem_init(void)
 {
-        unsigned long start;
-
         max_low_pfn = (high_physmem - uml_physmem) >> PAGE_SHIFT;
 
         /* clear the zero-page */
@@ -81,13 +77,6 @@ void mem_init(void)
         free_bootmem(__pa(brk_end), uml_reserved - brk_end);
         uml_reserved = brk_end;
 
-        /* Fill in any hole at the start of the binary */
-        start = (unsigned long) &__binary_start & PAGE_MASK;
-        if(uml_physmem != start){
-                map_memory(uml_physmem, __pa(uml_physmem), start - uml_physmem,
-                           1, 1, 0);
-        }
-
         /* this will put all low memory onto the freelists */
         totalram_pages = free_all_bootmem();
         totalhigh_pages = highmem >> PAGE_SHIFT;
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index 166cb09cae4c..abafa64b8727 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -317,7 +317,7 @@ void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
         }
 }
 
-extern int __syscall_stub_start, __binary_start;
+extern int __syscall_stub_start;
 
 void setup_physmem(unsigned long start, unsigned long reserve_end,
                    unsigned long len, unsigned long long highmem)
diff --git a/arch/um/kernel/skas/mem.c b/arch/um/kernel/skas/mem.c
index 7e5b8f165cf2..27bbf54b1e52 100644
--- a/arch/um/kernel/skas/mem.c
+++ b/arch/um/kernel/skas/mem.c
@@ -9,20 +9,19 @@
 #include "mem_user.h"
 #include "skas.h"
 
-unsigned long set_task_sizes_skas(unsigned long *host_size_out,
-                                  unsigned long *task_size_out)
+unsigned long set_task_sizes_skas(unsigned long *task_size_out)
 {
         /* Round up to the nearest 4M */
-        unsigned long top = ROUND_4M((unsigned long) &host_size_out);
+        unsigned long host_task_size = ROUND_4M((unsigned long)
+                                                &host_task_size);
 
 #ifdef CONFIG_HOST_TASK_SIZE
         *host_size_out = ROUND_4M(CONFIG_HOST_TASK_SIZE);
         *task_size_out = CONFIG_HOST_TASK_SIZE;
 #else
-        *host_size_out = top;
         if (!skas_needs_stub)
-                *task_size_out = top;
+                *task_size_out = host_task_size;
         else *task_size_out = CONFIG_STUB_START & PGDIR_MASK;
 #endif
-        return ((unsigned long) set_task_sizes_skas) & ~0xffffff;
+        return host_task_size;
 }
diff --git a/arch/um/kernel/tt/mem.c b/arch/um/kernel/tt/mem.c
index 4ae8c5c1e3b3..84a23b14f770 100644
--- a/arch/um/kernel/tt/mem.c
+++ b/arch/um/kernel/tt/mem.c
@@ -24,11 +24,13 @@ void before_mem_tt(unsigned long brk_start)
 #define SIZE ((CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS) * 0x20000000)
 #define START (CONFIG_TOP_ADDR - SIZE)
 
-unsigned long set_task_sizes_tt(unsigned long *host_size_out,
-                                unsigned long *task_size_out)
+unsigned long set_task_sizes_tt(unsigned long *task_size_out)
 {
+        unsigned long host_task_size;
+
         /* Round up to the nearest 4M */
-        *host_size_out = ROUND_4M((unsigned long) &host_size_out);
+        host_task_size = ROUND_4M((unsigned long) &host_task_size);
         *task_size_out = START;
-        return START;
+
+        return host_task_size;
 }
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index a50a0aac8faa..7896cf98232d 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -330,6 +330,8 @@ EXPORT_SYMBOL(end_iomem);
 
 #define MIN_VMALLOC (32 * 1024 * 1024)
 
+extern char __binary_start;
+
 int linux_main(int argc, char **argv)
 {
         unsigned long avail, diff;
@@ -374,8 +376,9 @@ int linux_main(int argc, char **argv)
 
         printf("UML running in %s mode\n", mode);
 
-        uml_start = CHOOSE_MODE_PROC(set_task_sizes_tt, set_task_sizes_skas,
-                                     &host_task_size, &task_size);
+        uml_start = (unsigned long) &__binary_start;
+        host_task_size = CHOOSE_MODE_PROC(set_task_sizes_tt,
+                                          set_task_sizes_skas, &task_size);
 
         /*
          * Setting up handlers to 'sig_info' struct
@@ -395,7 +398,7 @@ int linux_main(int argc, char **argv)
                 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
         }
 
-        uml_physmem = uml_start;
+        uml_physmem = uml_start & PAGE_MASK;
 
         /* Reserve up to 4M after the current brk */
         uml_reserved = ROUND_4M(brk_start) + (1 << 22);
diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index af11915ce0a8..8eca47a6ff08 100644
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -7,13 +7,16 @@ jiffies = jiffies_64;
 
 SECTIONS
 {
-  /*This must contain the right address - not quite the default ELF one.*/
+  /* This must contain the right address - not quite the default ELF one.*/
   PROVIDE (__executable_start = START);
-  . = START + SIZEOF_HEADERS;
+  /* Static binaries stick stuff here, like the sigreturn trampoline,
+   * invisibly to objdump.  So, just make __binary_start equal to the very
+   * beginning of the executable, and if there are unmapped pages after this,
+   * they are forever unusable.
+   */
+  __binary_start = START;
 
-  /* Used in arch/um/kernel/mem.c. Any memory between START and __binary_start
-   * is remapped.*/
-  __binary_start = .;
+  . = START + SIZEOF_HEADERS;
 
 #ifdef MODE_TT
   .remap_data : { UNMAP_PATH (.data .bss) }