uml: clean up TASK_SIZE usage
Clean up the calculation and use of the usable address space size on the host.
task_size is gone, replaced with TASK_SIZE, which is calculated from
CONFIG_TOP_ADDR. get_kmem_end and set_task_sizes_skas are also gone.
host_task_size, which refers to the entire address space usable by the UML
kernel and which may be larger than the address space usable by a UML process,
since that has to end on a pgdir boundary, is replaced by CONFIG_TOP_ADDR.
STACK_TOP is now TASK_SIZE minus the two stub pages.
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>
diff --git a/arch/um/include/as-layout.h b/arch/um/include/as-layout.h
index 2b859e0..a2008f5 100644
--- a/arch/um/include/as-layout.h
+++ b/arch/um/include/as-layout.h
@@ -29,9 +29,20 @@
#define _AC(X, Y) __AC(X, Y)
#endif
+/*
+ * The "- 1"'s are to avoid gcc complaining about integer overflows
+ * and unrepresentable decimal constants. With 3-level page tables,
+ * TASK_SIZE is 0x80000000, which gets turned into its signed decimal
+ * equivalent in asm-offsets.s. gcc then complains about that being
+ * unsigned only in C90. To avoid that, UM_TASK_SIZE is defined as
+ * TASK_SIZE - 1. To compensate, we need to add the 1 back here.
+ * However, adding it back to UM_TASK_SIZE produces more gcc
+ * complaints. So, I adjust the thing being subtracted from
+ * UM_TASK_SIZE instead. Bah.
+ */
#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)
+ UM_TASK_SIZE - (2 * UM_KERN_PAGE_SIZE - 1))
+#define STUB_DATA _AC((unsigned long), UM_TASK_SIZE - (UM_KERN_PAGE_SIZE - 1))
#define STUB_START _AC(, STUB_CODE)
#ifndef __ASSEMBLY__
diff --git a/arch/um/include/common-offsets.h b/arch/um/include/common-offsets.h
index b54bd35..5b67d7c 100644
--- a/arch/um/include/common-offsets.h
+++ b/arch/um/include/common-offsets.h
@@ -39,3 +39,6 @@
DEFINE(UM_USEC_PER_SEC, USEC_PER_SEC);
DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC);
DEFINE(UM_NSEC_PER_USEC, NSEC_PER_USEC);
+
+/* See as-layout.h for an explanation of the "- 1". Bah. */
+DEFINE(UM_TASK_SIZE, TASK_SIZE - 1);
diff --git a/arch/um/include/mem_user.h b/arch/um/include/mem_user.h
index a54514d..4e6707b 100644
--- a/arch/um/include/mem_user.h
+++ b/arch/um/include/mem_user.h
@@ -46,9 +46,6 @@
#define ROUND_4M(n) ((((unsigned long) (n)) + (1 << 22)) & ~((1 << 22) - 1))
-extern unsigned long host_task_size;
-extern unsigned long task_size;
-
extern int init_mem_user(void);
extern void setup_memory(void *entry);
extern unsigned long find_iomem(char *driver, unsigned long *len_out);
@@ -62,6 +59,5 @@
extern void unmap_physmem(void);
extern void map_memory(unsigned long virt, unsigned long phys,
unsigned long len, int r, int w, int x);
-extern unsigned long get_kmem_end(void);
#endif
diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index 8196450..bf66b5b 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -19,7 +19,7 @@
void flush_thread(void)
{
void *data = NULL;
- unsigned long end = proc_mm ? task_size : STUB_START;
+ unsigned long end = proc_mm ? TASK_SIZE : STUB_START;
int ret;
arch_flush_thread(¤t->thread.arch);
diff --git a/arch/um/kernel/ksyms.c b/arch/um/kernel/ksyms.c
index f0ced98..187a756 100644
--- a/arch/um/kernel/ksyms.c
+++ b/arch/um/kernel/ksyms.c
@@ -18,11 +18,8 @@
EXPORT_SYMBOL(get_signals);
EXPORT_SYMBOL(kernel_thread);
EXPORT_SYMBOL(sys_waitpid);
-EXPORT_SYMBOL(task_size);
EXPORT_SYMBOL(flush_tlb_range);
-EXPORT_SYMBOL(host_task_size);
EXPORT_SYMBOL(arch_validate);
-EXPORT_SYMBOL(get_kmem_end);
EXPORT_SYMBOL(high_physmem);
EXPORT_SYMBOL(empty_zero_page);
diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index e66432f..9c92900 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -55,16 +55,6 @@
return 0;
}
-/* Changed during early boot */
-static unsigned long kmem_top = 0;
-
-unsigned long get_kmem_end(void)
-{
- if (kmem_top == 0)
- kmem_top = host_task_size - 1024 * 1024;
- return kmem_top;
-}
-
void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
int r, int w, int x)
{
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 96e0978..429fed2 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -511,7 +511,7 @@
if (atomic_read(&mm->mm_users) == 0)
return;
- end = proc_mm ? task_size : 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 1139e07..9ba39ab 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -101,8 +101,6 @@
};
/* Set in linux_main */
-unsigned long host_task_size;
-unsigned long task_size;
unsigned long uml_physmem;
unsigned long uml_reserved; /* Also modified in mem_init */
unsigned long start_vm;
@@ -234,20 +232,6 @@
extern char __binary_start;
-static unsigned long set_task_sizes_skas(unsigned long *task_size_out)
-{
- /* Round up to the nearest 4M */
- unsigned long host_task_size = ROUND_4M((unsigned long)
- &host_task_size);
-
- if (!skas_needs_stub)
- *task_size_out = host_task_size;
- else
- *task_size_out = STUB_START & PGDIR_MASK;
-
- return host_task_size;
-}
-
int __init linux_main(int argc, char **argv)
{
unsigned long avail, diff;
@@ -278,8 +262,6 @@
printf("UML running in %s mode\n", mode);
- host_task_size = set_task_sizes_skas(&task_size);
-
brk_start = (unsigned long) sbrk(0);
/*
@@ -304,7 +286,7 @@
highmem = 0;
iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
- max_physmem = get_kmem_end() - uml_physmem - iomem_size - MIN_VMALLOC;
+ max_physmem = CONFIG_TOP_ADDR - uml_physmem - iomem_size - MIN_VMALLOC;
/*
* Zones have to begin on a 1 << MAX_ORDER page boundary,
@@ -336,7 +318,7 @@
}
virtmem_size = physmem_size;
- avail = get_kmem_end() - start_vm;
+ avail = CONFIG_TOP_ADDR - start_vm;
if (physmem_size > avail)
virtmem_size = avail;
end_vm = start_vm + virtmem_size;
diff --git a/include/asm-um/a.out.h b/include/asm-um/a.out.h
index 9281dd8..f42ff145 100644
--- a/include/asm-um/a.out.h
+++ b/include/asm-um/a.out.h
@@ -13,11 +13,9 @@
extern unsigned long stacksizelim;
-extern unsigned long host_task_size;
-
#define STACK_ROOM (stacksizelim)
-#define STACK_TOP task_size
+#define STACK_TOP (TASK_SIZE - 2 * PAGE_SIZE)
#define STACK_TOP_MAX STACK_TOP
diff --git a/include/asm-um/fixmap.h b/include/asm-um/fixmap.h
index 3d3e85d..89a87c1 100644
--- a/include/asm-um/fixmap.h
+++ b/include/asm-um/fixmap.h
@@ -56,9 +56,8 @@
* the start of the fixmap, and leave one page empty
* at the top of mem..
*/
-extern unsigned long get_kmem_end(void);
-#define FIXADDR_TOP (get_kmem_end() - 0x2000)
+#define FIXADDR_TOP (CONFIG_TOP_ADDR - 2 * PAGE_SIZE)
#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
diff --git a/include/asm-um/processor-generic.h b/include/asm-um/processor-generic.h
index 35ab6a2..ecf6706 100644
--- a/include/asm-um/processor-generic.h
+++ b/include/asm-um/processor-generic.h
@@ -94,9 +94,7 @@
/*
* User space process size: 3GB (default).
*/
-extern unsigned long task_size;
-
-#define TASK_SIZE (task_size)
+#define TASK_SIZE (CONFIG_TOP_ADDR & PGDIR_MASK)
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.