X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=mm%2Fmmap.c;h=88da687bde89fdc51b367c1728d330b3321568ab;hb=fd76bab2fa6d8f3ef6b326a4c6ae442fa21d30a4;hp=9717337293c3a7f3eb51ed60d70369efa8a24bb3;hpb=463e7c7cf9aaf95dd05e97e1a47854fdf5454cdc;p=powerpc.git

diff --git a/mm/mmap.c b/mm/mmap.c
index 9717337293..88da687bde 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -29,6 +29,7 @@
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>
 #include <asm/tlb.h>
+#include <asm/mmu_context.h>
 
 #ifndef arch_mmap_check
 #define arch_mmap_check(addr, len, flags)	(0)
@@ -299,6 +300,8 @@ static int browse_rb(struct rb_root *root)
 			printk("vm_end %lx < vm_start %lx\n", vma->vm_end, vma->vm_start);
 		i++;
 		pn = nd;
+		prev = vma->vm_start;
+		pend = vma->vm_end;
 	}
 	j = 0;
 	for (nd = pn; nd; nd = rb_prev(nd)) {
@@ -1477,6 +1480,7 @@ static int acct_stack_growth(struct vm_area_struct * vma, unsigned long size, un
 {
 	struct mm_struct *mm = vma->vm_mm;
 	struct rlimit *rlim = current->signal->rlim;
+	unsigned long new_start;
 
 	/* address space limit tests */
 	if (!may_expand_vm(mm, grow))
@@ -1496,6 +1500,12 @@ static int acct_stack_growth(struct vm_area_struct * vma, unsigned long size, un
 			return -ENOMEM;
 	}
 
+	/* Check to ensure the stack will not grow into a hugetlb-only region */
+	new_start = (vma->vm_flags & VM_GROWSUP) ? vma->vm_start :
+			vma->vm_end - size;
+	if (is_hugepage_only_range(vma->vm_mm, new_start, size))
+		return -EFAULT;
+
 	/*
 	 * Overcommit..  This must be the final test, as it will
 	 * update security statistics.
@@ -1970,6 +1980,9 @@ void exit_mmap(struct mm_struct *mm)
 	unsigned long nr_accounted = 0;
 	unsigned long end;
 
+	/* mm's last user has gone, and its about to be pulled down */
+	arch_exit_mmap(mm);
+
 	lru_add_drain();
 	flush_cache_mm(mm);
 	tlb = tlb_gather_mmu(mm, 1);
@@ -2094,3 +2107,75 @@ int may_expand_vm(struct mm_struct *mm, unsigned long npages)
 		return 0;
 	return 1;
 }
+
+
+static struct page *special_mapping_nopage(struct vm_area_struct *vma,
+					   unsigned long address, int *type)
+{
+	struct page **pages;
+
+	BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+
+	address -= vma->vm_start;
+	for (pages = vma->vm_private_data; address > 0 && *pages; ++pages)
+		address -= PAGE_SIZE;
+
+	if (*pages) {
+		struct page *page = *pages;
+		get_page(page);
+		return page;
+	}
+
+	return NOPAGE_SIGBUS;
+}
+
+/*
+ * Having a close hook prevents vma merging regardless of flags.
+ */
+static void special_mapping_close(struct vm_area_struct *vma)
+{
+}
+
+static struct vm_operations_struct special_mapping_vmops = {
+	.close = special_mapping_close,
+	.nopage	= special_mapping_nopage,
+};
+
+/*
+ * Called with mm->mmap_sem held for writing.
+ * Insert a new vma covering the given region, with the given flags.
+ * Its pages are supplied by the given array of struct page *.
+ * The array can be shorter than len >> PAGE_SHIFT if it's null-terminated.
+ * The region past the last page supplied will always produce SIGBUS.
+ * The array pointer and the pages it points to are assumed to stay alive
+ * for as long as this mapping might exist.
+ */
+int install_special_mapping(struct mm_struct *mm,
+			    unsigned long addr, unsigned long len,
+			    unsigned long vm_flags, struct page **pages)
+{
+	struct vm_area_struct *vma;
+
+	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+	if (unlikely(vma == NULL))
+		return -ENOMEM;
+
+	vma->vm_mm = mm;
+	vma->vm_start = addr;
+	vma->vm_end = addr + len;
+
+	vma->vm_flags = vm_flags | mm->def_flags;
+	vma->vm_page_prot = protection_map[vma->vm_flags & 7];
+
+	vma->vm_ops = &special_mapping_vmops;
+	vma->vm_private_data = pages;
+
+	if (unlikely(insert_vm_struct(mm, vma))) {
+		kmem_cache_free(vm_area_cachep, vma);
+		return -ENOMEM;
+	}
+
+	mm->total_vm += len >> PAGE_SHIFT;
+
+	return 0;
+}