add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/arch/s390/mm/mmap.c
..
..
@@ -17,25 +17,14 @@
17
17
 #include <linux/random.h>
18
18
 #include <linux/compat.h>
19
19
 #include <linux/security.h>
20
-#include <asm/pgalloc.h>
21
20
 #include <asm/elf.h>
22
21
 
23
22
 static unsigned long stack_maxrandom_size(void)
24
23
 {
25
24
 	if (!(current->flags & PF_RANDOMIZE))
26
25
 		return 0;
27
-	if (current->personality & ADDR_NO_RANDOMIZE)
28
-		return 0;
29
26
 	return STACK_RND_MASK << PAGE_SHIFT;
30
27
 }
31
-
32
-/*
33
- * Top of mmap area (just below the process stack).
34
- *
35
- * Leave at least a ~32 MB hole.
36
- */
37
-#define MIN_GAP (32*1024*1024)
38
-#define MAX_GAP (STACK_TOP/6*5)
39
28
 
40
29
 static inline int mmap_is_legacy(struct rlimit *rlim_stack)
41
30
 {
..
..
@@ -60,23 +49,35 @@
60
49
 				      struct rlimit *rlim_stack)
61
50
 {
62
51
 	unsigned long gap = rlim_stack->rlim_cur;
52
+	unsigned long pad = stack_maxrandom_size() + stack_guard_gap;
53
+	unsigned long gap_min, gap_max;
63
54
 
64
-	if (gap < MIN_GAP)
65
-		gap = MIN_GAP;
66
-	else if (gap > MAX_GAP)
67
-		gap = MAX_GAP;
68
-	gap &= PAGE_MASK;
69
-	return STACK_TOP - stack_maxrandom_size() - rnd - gap;
55
+	/* Values close to RLIM_INFINITY can overflow. */
56
+	if (gap + pad > gap)
57
+		gap += pad;
58
+
59
+	/*
60
+	 * Top of mmap area (just below the process stack).
61
+	 * Leave at least a ~32 MB hole.
62
+	 */
63
+	gap_min = 32 * 1024 * 1024UL;
64
+	gap_max = (STACK_TOP / 6) * 5;
65
+
66
+	if (gap < gap_min)
67
+		gap = gap_min;
68
+	else if (gap > gap_max)
69
+		gap = gap_max;
70
+
71
+	return PAGE_ALIGN(STACK_TOP - gap - rnd);
70
72
 }
71
73
 
72
-unsigned long
73
-arch_get_unmapped_area(struct file *filp, unsigned long addr,
74
-		unsigned long len, unsigned long pgoff, unsigned long flags)
74
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
75
+				     unsigned long len, unsigned long pgoff,
76
+				     unsigned long flags)
75
77
 {
76
78
 	struct mm_struct *mm = current->mm;
77
79
 	struct vm_area_struct *vma;
78
80
 	struct vm_unmapped_area_info info;
79
-	int rc;
80
81
 
81
82
 	if (len > TASK_SIZE - mmap_min_addr)
82
83
 		return -ENOMEM;
..
..
@@ -102,30 +103,20 @@
102
103
 		info.align_mask = 0;
103
104
 	info.align_offset = pgoff << PAGE_SHIFT;
104
105
 	addr = vm_unmapped_area(&info);
105
-	if (addr & ~PAGE_MASK)
106
+	if (offset_in_page(addr))
106
107
 		return addr;
107
108
 
108
109
 check_asce_limit:
109
-	if (addr + len > current->mm->context.asce_limit &&
110
-	    addr + len <= TASK_SIZE) {
111
-		rc = crst_table_upgrade(mm, addr + len);
112
-		if (rc)
113
-			return (unsigned long) rc;
114
-	}
115
-
116
-	return addr;
110
+	return check_asce_limit(mm, addr, len);
117
111
 }
118
112
 
119
-unsigned long
120
-arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
121
-			  const unsigned long len, const unsigned long pgoff,
122
-			  const unsigned long flags)
113
+unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
114
+					     unsigned long len, unsigned long pgoff,
115
+					     unsigned long flags)
123
116
 {
124
117
 	struct vm_area_struct *vma;
125
118
 	struct mm_struct *mm = current->mm;
126
-	unsigned long addr = addr0;
127
119
 	struct vm_unmapped_area_info info;
128
-	int rc;
129
120
 
130
121
 	/* requested length too big for entire address space */
131
122
 	if (len > TASK_SIZE - mmap_min_addr)
..
..
@@ -160,25 +151,18 @@
160
151
 	 * can happen with large stack limits and large mmap()
161
152
 	 * allocations.
162
153
 	 */
163
-	if (addr & ~PAGE_MASK) {
154
+	if (offset_in_page(addr)) {
164
155
 		VM_BUG_ON(addr != -ENOMEM);
165
156
 		info.flags = 0;
166
157
 		info.low_limit = TASK_UNMAPPED_BASE;
167
158
 		info.high_limit = TASK_SIZE;
168
159
 		addr = vm_unmapped_area(&info);
169
-		if (addr & ~PAGE_MASK)
160
+		if (offset_in_page(addr))
170
161
 			return addr;
171
162
 	}
172
163
 
173
164
 check_asce_limit:
174
-	if (addr + len > current->mm->context.asce_limit &&
175
-	    addr + len <= TASK_SIZE) {
176
-		rc = crst_table_upgrade(mm, addr + len);
177
-		if (rc)
178
-			return (unsigned long) rc;
179
-	}
180
-
181
-	return addr;
165
+	return check_asce_limit(mm, addr, len);
182
166
 }
183
167
 
184
168
 /*