Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

torvalds · torvalds · commit ca043a66ae48 · 2009-09-17T20:58:11.000-07:00
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, pat: don't use rb-tree based lookup in reserve_memtype()
  x86: Increase MIN_GAP to include randomized stack
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
@@ -299,6 +299,8 @@ do {									\
 
 #ifdef CONFIG_X86_32
 
+#define STACK_RND_MASK (0x7ff)
+
 #define VDSO_HIGH_BASE		(__fix_to_virt(FIX_VDSO))
 
 #define ARCH_DLINFO		ARCH_DLINFO_IA32(vdso_enabled)
diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
@@ -29,13 +29,26 @@
 #include <linux/random.h>
 #include <linux/limits.h>
 #include <linux/sched.h>
+#include <asm/elf.h>
+
+static unsigned int stack_maxrandom_size(void)
+{
+	unsigned int max = 0;
+	if ((current->flags & PF_RANDOMIZE) &&
+		!(current->personality & ADDR_NO_RANDOMIZE)) {
+		max = ((-1U) & STACK_RND_MASK) << PAGE_SHIFT;
+	}
+
+	return max;
+}
+
 
 /*
  * Top of mmap area (just below the process stack).
  *
- * Leave an at least ~128 MB hole.
+ * Leave an at least ~128 MB hole with possible stack randomization.
  */
-#define MIN_GAP (128*1024*1024)
+#define MIN_GAP (128*1024*1024UL + stack_maxrandom_size())
 #define MAX_GAP (TASK_SIZE/6*5)
 
 /*
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
@@ -424,17 +424,9 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
 
 	spin_lock(&memtype_lock);
 
-	entry = memtype_rb_search(&memtype_rbroot, new->start);
-	if (likely(entry != NULL)) {
-		/* To work correctly with list_for_each_entry_continue */
-		entry = list_entry(entry->nd.prev, struct memtype, nd);
-	} else {
-		entry = list_entry(&memtype_list, struct memtype, nd);
-	}
-
 	/* Search for existing mapping that overlaps the current range */
 	where = NULL;
-	list_for_each_entry_continue(entry, &memtype_list, nd) {
+	list_for_each_entry(entry, &memtype_list, nd) {
 		if (end <= entry->start) {
 			where = entry->nd.prev;
 			break;
@@ -532,7 +524,7 @@ int free_memtype(u64 start, u64 end)
 	 * in sorted start address
 	 */
 	saved_entry = entry;
-	list_for_each_entry(entry, &memtype_list, nd) {
+	list_for_each_entry_from(entry, &memtype_list, nd) {
 		if (entry->start == start && entry->end == end) {
 			rb_erase(&entry->rb, &memtype_rbroot);
 			list_del(&entry->nd);
