mm: Add a flag MAP_VA32BIT for mmap

ascend inclusion
category: bugfix
bugzilla: NA
CVE: NA

-------------------

There is a bug in dvpp. The virtual address used by dvpp must
have same higt 16bits.

Add a MAP_VA32BIT for mmap. mmap(..., MAP_VA32BIT) will return
the virtual address with same higt 16bits.
Signed-off-by: NJiankang Chen <chenjiankang1@huawei.com>
Signed-off-by: NZhou Guanghui <zhouguanghui1@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NLijun Fang <fanglijun3@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/include/asm/processor.h

@@ -70,6 +70,8 @@
 #define TASK_SIZE		TASK_SIZE_64
 #endif /* CONFIG_COMPAT */
 
+#define MMAP_TOP_4G_SIZE	(0x100000000UL)
+
 #define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE / 4))
 
 #define STACK_TOP_MAX		TASK_SIZE_64

fs/hugetlbfs/inode.c

@@ -215,6 +215,10 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 
 	if (addr) {
 		addr = ALIGN(addr, huge_page_size(h));
+
+		if (!mmap_va32bit_check(addr, len, flags))
+			return -ENOMEM;
+
 		vma = find_vma(mm, addr);
 		if (TASK_SIZE - len >= addr &&
 		    (!vma || addr + len <= vm_start_gap(vma)))
@@ -227,6 +231,9 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 	info.high_limit = TASK_SIZE;
 	info.align_mask = PAGE_MASK & ~huge_page_mask(h);
 	info.align_offset = 0;
+
+	mmap_va32bit_set_limit(&info, flags);
+
 	return vm_unmapped_area(&info);
 }
 #endif

include/linux/mm.h

@@ -2360,6 +2360,29 @@ struct vm_unmapped_area_info {
 	unsigned long align_offset;
 };
 
+
+#ifdef CONFIG_ARCH_ASCEND
+
+extern int mmap_va32bit_check(unsigned long addr, unsigned long len,
+			      unsigned long flags);
+extern void mmap_va32bit_set_limit(struct vm_unmapped_area_info *info,
+				   unsigned long flags);
+
+#else
+
+static inline int mmap_va32bit_check(unsigned long addr, unsigned long len,
+				     unsigned long flags)
+{
+	return 1;
+}
+
+static inline void mmap_va32bit_set_limit(struct vm_unmapped_area_info *info,
+					  unsigned long flags)
+{
+}
+
+#endif
+
 extern unsigned long unmapped_area(struct vm_unmapped_area_info *info);
 extern unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info);
 

include/uapi/asm-generic/mman.h

@@ -14,6 +14,7 @@
 #define MAP_STACK	0x20000		/* give out an address that is best suited for process/thread stacks */
 #define MAP_HUGETLB	0x40000		/* create a huge page mapping */
 #define MAP_SYNC	0x80000		/* perform synchronous page faults for the mapping */
+#define MAP_VA32BIT	0x0200
 
 /* Bits [26:31] are reserved, see mman-common.h for MAP_HUGETLB usage */
 

mm/mmap.c

@@ -1841,6 +1841,38 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 	return error;
 }
 
+#ifdef CONFIG_ARCH_ASCEND
+
+int mmap_va32bit_check(unsigned long addr, unsigned long len,
+		       unsigned long flags)
+{
+	return !(!(flags & MAP_VA32BIT) &&
+		((addr + len) > (TASK_SIZE - MMAP_TOP_4G_SIZE)) &&
+		(addr < TASK_SIZE));
+}
+
+
+void mmap_va32bit_set_limit(struct vm_unmapped_area_info *info,
+			    unsigned long flags)
+{
+	const unsigned long high_limit = TASK_SIZE;
+	const unsigned long divide = TASK_SIZE - MMAP_TOP_4G_SIZE;
+
+	if (info == NULL)
+		return;
+
+	if (flags & MAP_VA32BIT) {
+		info->low_limit = divide;
+		info->high_limit = high_limit;
+	} else {
+		/* low_limit do not need set */
+		if (info->high_limit > divide)
+			info->high_limit = divide;
+	}
+}
+
+#endif
+
 unsigned long unmapped_area(struct vm_unmapped_area_info *info)
 {
 	/*
@@ -2071,6 +2103,10 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 
 	if (addr) {
 		addr = PAGE_ALIGN(addr);
+
+		if (!mmap_va32bit_check(addr, len, flags))
+			return -ENOMEM;
+
 		vma = find_vma_prev(mm, addr, &prev);
 		if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
 		    (!vma || addr + len <= vm_start_gap(vma)) &&
@@ -2083,6 +2119,9 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 	info.low_limit = mm->mmap_base;
 	info.high_limit = TASK_SIZE;
 	info.align_mask = 0;
+
+	mmap_va32bit_set_limit(&info, flags);
+
 	return vm_unmapped_area(&info);
 }
 #endif
@@ -2112,6 +2151,10 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 	/* requesting a specific address */
 	if (addr) {
 		addr = PAGE_ALIGN(addr);
+
+		if (!mmap_va32bit_check(addr, len, flags))
+			return -ENOMEM;
+
 		vma = find_vma_prev(mm, addr, &prev);
 		if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
 				(!vma || addr + len <= vm_start_gap(vma)) &&
@@ -2124,6 +2167,9 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 	info.low_limit = max(PAGE_SIZE, mmap_min_addr);
 	info.high_limit = mm->mmap_base;
 	info.align_mask = 0;
+
+	mmap_va32bit_set_limit(&info, flags);
+
 	addr = vm_unmapped_area(&info);
 
 	/*
@@ -2137,6 +2183,9 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 		info.flags = 0;
 		info.low_limit = TASK_UNMAPPED_BASE;
 		info.high_limit = TASK_SIZE;
+
+		mmap_va32bit_set_limit(&info, flags);
+
 		addr = vm_unmapped_area(&info);
 	}