1 files changed, 263 insertions, 34 deletions

diff --git a/arch/sparc64/kernel/sys_sparc.c b/arch/sparc64/kernel/sys_sparc.c
index 5f8c822..7a86913 100644
--- a/arch/sparc64/kernel/sys_sparc.c
+++ b/arch/sparc64/kernel/sys_sparc.c
@@ -25,25 +25,93 @@
 #include <linux/syscalls.h>
 #include <linux/ipc.h>
 #include <linux/personality.h>
+#include <linux/random.h>
 
 #include <asm/uaccess.h>
 #include <asm/ipc.h>
 #include <asm/utrap.h>
 #include <asm/perfctr.h>
+#include <asm/a.out.h>
 
 /* #define DEBUG_UNIMP_SYSCALL */
 
-/* XXX Make this per-binary type, this way we can detect the type of
- * XXX a binary.  Every Sparc executable calls this very early on.
- */
 asmlinkage unsigned long sys_getpagesize(void)
 {
 	return PAGE_SIZE;
 }
 
-#define COLOUR_ALIGN(addr,pgoff)		\
-	((((addr)+SHMLBA-1)&~(SHMLBA-1)) +	\
-	 (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
+#define VA_EXCLUDE_START (0x0000080000000000UL - (1UL << 32UL))
+#define VA_EXCLUDE_END   (0xfffff80000000000UL + (1UL << 32UL))
+
+/* Does addr --> addr+len fall within 4GB of the VA-space hole or
+ * overflow past the end of the 64-bit address space?
+ */
+static inline int invalid_64bit_range(unsigned long addr, unsigned long len)
+{
+	unsigned long va_exclude_start, va_exclude_end;
+
+	va_exclude_start = VA_EXCLUDE_START;
+	va_exclude_end   = VA_EXCLUDE_END;
+
+	if (unlikely(len >= va_exclude_start))
+		return 1;
+
+	if (unlikely((addr + len) < addr))
+		return 1;
+
+	if (unlikely((addr >= va_exclude_start && addr < va_exclude_end) ||
+		     ((addr + len) >= va_exclude_start &&
+		      (addr + len) < va_exclude_end)))
+		return 1;
+
+	return 0;
+}
+
+/* Does start,end straddle the VA-space hole?  */
+static inline int straddles_64bit_va_hole(unsigned long start, unsigned long end)
+{
+	unsigned long va_exclude_start, va_exclude_end;
+
+	va_exclude_start = VA_EXCLUDE_START;
+	va_exclude_end   = VA_EXCLUDE_END;
+
+	if (likely(start < va_exclude_start && end < va_exclude_start))
+		return 0;
+
+	if (likely(start >= va_exclude_end && end >= va_exclude_end))
+		return 0;
+
+	return 1;
+}
+
+/* These functions differ from the default implementations in
+ * mm/mmap.c in two ways:
+ *
+ * 1) For file backed MAP_SHARED mmap()'s we D-cache color align,
+ *    for fixed such mappings we just validate what the user gave us.
+ * 2) For 64-bit tasks we avoid mapping anything within 4GB of
+ *    the spitfire/niagara VA-hole.
+ */
+
+static inline unsigned long COLOUR_ALIGN(unsigned long addr,
+					 unsigned long pgoff)
+{
+	unsigned long base = (addr+SHMLBA-1)&~(SHMLBA-1);
+	unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
+
+	return base + off;
+}
+
+static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
+					      unsigned long pgoff)
+{
+	unsigned long base = addr & ~(SHMLBA-1);
+	unsigned long off = (pgoff<<PAGE_SHIFT) & (SHMLBA-1);
+
+	if (base + off <= addr)
+		return base + off;
+	return base - off;
+}
 
 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 {
@@ -64,8 +132,8 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
 	}
 
 	if (test_thread_flag(TIF_32BIT))
-		task_size = 0xf0000000UL;
-	if (len > task_size || len > -PAGE_OFFSET)
+		task_size = STACK_TOP32;
+	if (unlikely(len > task_size || len >= VA_EXCLUDE_START))
 		return -ENOMEM;
 
 	do_color_align = 0;
@@ -84,11 +152,12 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsi
 			return addr;
 	}
 
-	if (len <= mm->cached_hole_size) {
+	if (len > mm->cached_hole_size) {
+	        start_addr = addr = mm->free_area_cache;
+	} else {
+	        start_addr = addr = TASK_UNMAPPED_BASE;
 	        mm->cached_hole_size = 0;
-		mm->free_area_cache = TASK_UNMAPPED_BASE;
 	}
-	start_addr = addr = mm->free_area_cache;
 
 	task_size -= len;
 
@@ -100,11 +169,12 @@ full_search:
 
 	for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
 		/* At this point:  (!vma || addr < vma->vm_end). */
-		if (addr < PAGE_OFFSET && -PAGE_OFFSET - len < addr) {
-			addr = PAGE_OFFSET;
-			vma = find_vma(mm, PAGE_OFFSET);
+		if (addr < VA_EXCLUDE_START &&
+		    (addr + len) >= VA_EXCLUDE_START) {
+			addr = VA_EXCLUDE_END;
+			vma = find_vma(mm, VA_EXCLUDE_END);
 		}
-		if (task_size < addr) {
+		if (unlikely(task_size < addr)) {
 			if (start_addr != TASK_UNMAPPED_BASE) {
 				start_addr = addr = TASK_UNMAPPED_BASE;
 				mm->cached_hole_size = 0;
@@ -112,7 +182,7 @@ full_search:
 			}
 			return -ENOMEM;
 		}
-		if (!vma || addr + len <= vma->vm_start) {
+		if (likely(!vma || addr + len <= vma->vm_start)) {
 			/*
 			 * Remember the place where we stopped the search:
 			 */
@@ -128,6 +198,121 @@ full_search:
 	}
 }
 
+unsigned long
+arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
+			  const unsigned long len, const unsigned long pgoff,
+			  const unsigned long flags)
+{
+	struct vm_area_struct *vma;
+	struct mm_struct *mm = current->mm;
+	unsigned long task_size = STACK_TOP32;
+	unsigned long addr = addr0;
+	int do_color_align;
+
+	/* This should only ever run for 32-bit processes.  */
+	BUG_ON(!test_thread_flag(TIF_32BIT));
+
+	if (flags & MAP_FIXED) {
+		/* We do not accept a shared mapping if it would violate
+		 * cache aliasing constraints.
+		 */
+		if ((flags & MAP_SHARED) &&
+		    ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
+			return -EINVAL;
+		return addr;
+	}
+
+	if (unlikely(len > task_size))
+		return -ENOMEM;
+
+	do_color_align = 0;
+	if (filp || (flags & MAP_SHARED))
+		do_color_align = 1;
+
+	/* requesting a specific address */
+	if (addr) {
+		if (do_color_align)
+			addr = COLOUR_ALIGN(addr, pgoff);
+		else
+			addr = PAGE_ALIGN(addr);
+
+		vma = find_vma(mm, addr);
+		if (task_size - len >= addr &&
+		    (!vma || addr + len <= vma->vm_start))
+			return addr;
+	}
+
+	/* check if free_area_cache is useful for us */
+	if (len <= mm->cached_hole_size) {
+ 	        mm->cached_hole_size = 0;
+ 		mm->free_area_cache = mm->mmap_base;
+ 	}
+
+	/* either no address requested or can't fit in requested address hole */
+	addr = mm->free_area_cache;
+	if (do_color_align) {
+		unsigned long base = COLOUR_ALIGN_DOWN(addr-len, pgoff);
+
+		addr = base + len;
+	}
+
+	/* make sure it can fit in the remaining address space */
+	if (likely(addr > len)) {
+		vma = find_vma(mm, addr-len);
+		if (!vma || addr <= vma->vm_start) {
+			/* remember the address as a hint for next time */
+			return (mm->free_area_cache = addr-len);
+		}
+	}
+
+	if (unlikely(mm->mmap_base < len))
+		goto bottomup;
+
+	addr = mm->mmap_base-len;
+	if (do_color_align)
+		addr = COLOUR_ALIGN_DOWN(addr, pgoff);
+
+	do {
+		/*
+		 * Lookup failure means no vma is above this address,
+		 * else if new region fits below vma->vm_start,
+		 * return with success:
+		 */
+		vma = find_vma(mm, addr);
+		if (likely(!vma || addr+len <= vma->vm_start)) {
+			/* remember the address as a hint for next time */
+			return (mm->free_area_cache = addr);
+		}
+
+ 		/* remember the largest hole we saw so far */
+ 		if (addr + mm->cached_hole_size < vma->vm_start)
+ 		        mm->cached_hole_size = vma->vm_start - addr;
+
+		/* try just below the current vma->vm_start */
+		addr = vma->vm_start-len;
+		if (do_color_align)
+			addr = COLOUR_ALIGN_DOWN(addr, pgoff);
+	} while (likely(len < vma->vm_start));
+
+bottomup:
+	/*
+	 * A failed mmap() very likely causes application failure,
+	 * so fall back to the bottom-up function here. This scenario
+	 * can happen with large stack limits and large mmap()
+	 * allocations.
+	 */
+	mm->cached_hole_size = ~0UL;
+  	mm->free_area_cache = TASK_UNMAPPED_BASE;
+	addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
+	/*
+	 * Restore the topdown base:
+	 */
+	mm->free_area_cache = mm->mmap_base;
+	mm->cached_hole_size = ~0UL;
+
+	return addr;
+}
+
 /* Try to align mapping such that we align it as much as possible. */
 unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 {
@@ -171,15 +356,57 @@ unsigned long get_fb_unmapped_area(struct file *filp, unsigned long orig_addr, u
 	return addr;
 }
 
+/* Essentially the same as PowerPC... */
+void arch_pick_mmap_layout(struct mm_struct *mm)
+{
+	unsigned long random_factor = 0UL;
+
+	if (current->flags & PF_RANDOMIZE) {
+		random_factor = get_random_int();
+		if (test_thread_flag(TIF_32BIT))
+			random_factor &= ((1 * 1024 * 1024) - 1);
+		else
+			random_factor = ((random_factor << PAGE_SHIFT) &
+					 0xffffffffUL);
+	}
+
+	/*
+	 * Fall back to the standard layout if the personality
+	 * bit is set, or if the expected stack growth is unlimited:
+	 */
+	if (!test_thread_flag(TIF_32BIT) ||
+	    (current->personality & ADDR_COMPAT_LAYOUT) ||
+	    current->signal->rlim[RLIMIT_STACK].rlim_cur == RLIM_INFINITY ||
+	    sysctl_legacy_va_layout) {
+		mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
+		mm->get_unmapped_area = arch_get_unmapped_area;
+		mm->unmap_area = arch_unmap_area;
+	} else {
+		/* We know it's 32-bit */
+		unsigned long task_size = STACK_TOP32;
+		unsigned long gap;
+
+		gap = current->signal->rlim[RLIMIT_STACK].rlim_cur;
+		if (gap < 128 * 1024 * 1024)
+			gap = 128 * 1024 * 1024;
+		if (gap > (task_size / 6 * 5))
+			gap = (task_size / 6 * 5);
+
+		mm->mmap_base = PAGE_ALIGN(task_size - gap - random_factor);
+		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
+		mm->unmap_area = arch_unmap_area_topdown;
+	}
+}
+
 asmlinkage unsigned long sparc_brk(unsigned long brk)
 {
 	/* People could try to be nasty and use ta 0x6d in 32bit programs */
-	if (test_thread_flag(TIF_32BIT) &&
-	    brk >= 0xf0000000UL)
+	if (test_thread_flag(TIF_32BIT) && brk >= STACK_TOP32)
 		return current->mm->brk;
 
-	if ((current->mm->brk & PAGE_OFFSET) != (brk & PAGE_OFFSET))
+	if (unlikely(straddles_64bit_va_hole(current->mm->brk, brk)))
 		return current->mm->brk;
+
 	return sys_brk(brk);
 }
                                                                 
@@ -340,13 +567,16 @@ asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
 	retval = -EINVAL;
 
 	if (test_thread_flag(TIF_32BIT)) {
-		if (len > 0xf0000000UL ||
-		    ((flags & MAP_FIXED) && addr > 0xf0000000UL - len))
+		if (len >= STACK_TOP32)
+			goto out_putf;
+
+		if ((flags & MAP_FIXED) && addr > STACK_TOP32 - len)
 			goto out_putf;
 	} else {
-		if (len > -PAGE_OFFSET ||
-		    ((flags & MAP_FIXED) &&
-		     addr < PAGE_OFFSET && addr + len > -PAGE_OFFSET))
+		if (len >= VA_EXCLUDE_START)
+			goto out_putf;
+
+		if ((flags & MAP_FIXED) && invalid_64bit_range(addr, len))
 			goto out_putf;
 	}
 
@@ -365,9 +595,9 @@ asmlinkage long sys64_munmap(unsigned long addr, size_t len)
 {
 	long ret;
 
-	if (len > -PAGE_OFFSET ||
-	    (addr < PAGE_OFFSET && addr + len > -PAGE_OFFSET))
+	if (invalid_64bit_range(addr, len))
 		return -EINVAL;
+
 	down_write(&current->mm->mmap_sem);
 	ret = do_munmap(current->mm, addr, len);
 	up_write(&current->mm->mmap_sem);
@@ -384,18 +614,19 @@ asmlinkage unsigned long sys64_mremap(unsigned long addr,
 {
 	struct vm_area_struct *vma;
 	unsigned long ret = -EINVAL;
+
 	if (test_thread_flag(TIF_32BIT))
 		goto out;
-	if (old_len > -PAGE_OFFSET || new_len > -PAGE_OFFSET)
+	if (unlikely(new_len >= VA_EXCLUDE_START))
 		goto out;
-	if (addr < PAGE_OFFSET && addr + old_len > -PAGE_OFFSET)
+	if (unlikely(invalid_64bit_range(addr, old_len)))
 		goto out;
+
 	down_write(&current->mm->mmap_sem);
 	if (flags & MREMAP_FIXED) {
-		if (new_addr < PAGE_OFFSET &&
-		    new_addr + new_len > -PAGE_OFFSET)
+		if (invalid_64bit_range(new_addr, new_len))
 			goto out_sem;
-	} else if (addr < PAGE_OFFSET && addr + new_len > -PAGE_OFFSET) {
+	} else if (invalid_64bit_range(addr, new_len)) {
 		unsigned long map_flags = 0;
 		struct file *file = NULL;
 
@@ -554,12 +785,10 @@ asmlinkage long sys_utrap_install(utrap_entry_t type,
 	}
 	if (!current_thread_info()->utraps) {
 		current_thread_info()->utraps =
-			kmalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long), GFP_KERNEL);
+			kzalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long), GFP_KERNEL);
 		if (!current_thread_info()->utraps)
 			return -ENOMEM;
 		current_thread_info()->utraps[0] = 1;
-		memset(current_thread_info()->utraps+1, 0,
-		       UT_TRAP_INSTRUCTION_31*sizeof(long));
 	} else {
 		if ((utrap_handler_t)current_thread_info()->utraps[type] != new_p &&
 		    current_thread_info()->utraps[0] > 1) {