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1#include <linux/errno.h>
2#include <linux/sched.h>
3#include <linux/syscalls.h>
4#include <linux/mm.h>
5#include <linux/fs.h>
6#include <linux/smp.h>
7#include <linux/sem.h>
8#include <linux/msg.h>
9#include <linux/shm.h>
10#include <linux/stat.h>
11#include <linux/mman.h>
12#include <linux/file.h>
13#include <linux/utsname.h>
14#include <linux/personality.h>
15#include <linux/random.h>
16#include <linux/uaccess.h>
17#include <linux/elf.h>
18
19#include <asm/ia32.h>
20#include <asm/syscalls.h>
21
22/*
23 * Align a virtual address to avoid aliasing in the I$ on AMD F15h.
24 *
25 * @flags denotes the allocation direction - bottomup or topdown -
26 * or vDSO; see call sites below.
27 */
28unsigned long align_addr(unsigned long addr, struct file *filp,
29 enum align_flags flags)
30{
31 unsigned long tmp_addr;
32
33 /* handle 32- and 64-bit case with a single conditional */
34 if (va_align.flags < 0 || !(va_align.flags & (2 - mmap_is_ia32())))
35 return addr;
36
37 if (!(current->flags & PF_RANDOMIZE))
38 return addr;
39
40 if (!((flags & ALIGN_VDSO) || filp))
41 return addr;
42
43 tmp_addr = addr;
44
45 /*
46 * We need an address which is <= than the original
47 * one only when in topdown direction.
48 */
49 if (!(flags & ALIGN_TOPDOWN))
50 tmp_addr += va_align.mask;
51
52 tmp_addr &= ~va_align.mask;
53
54 return tmp_addr;
55}
56
57static int __init control_va_addr_alignment(char *str)
58{
59 /* guard against enabling this on other CPU families */
60 if (va_align.flags < 0)
61 return 1;
62
63 if (*str == 0)
64 return 1;
65
66 if (*str == '=')
67 str++;
68
69 if (!strcmp(str, "32"))
70 va_align.flags = ALIGN_VA_32;
71 else if (!strcmp(str, "64"))
72 va_align.flags = ALIGN_VA_64;
73 else if (!strcmp(str, "off"))
74 va_align.flags = 0;
75 else if (!strcmp(str, "on"))
76 va_align.flags = ALIGN_VA_32 | ALIGN_VA_64;
77 else
78 return 0;
79
80 return 1;
81}
82__setup("align_va_addr", control_va_addr_alignment);
83
84SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
85 unsigned long, prot, unsigned long, flags,
86 unsigned long, fd, unsigned long, off)
87{
88 long error;
89 error = -EINVAL;
90 if (off & ~PAGE_MASK)
91 goto out;
92
93 error = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
94out:
95 return error;
96}
97
98static void find_start_end(unsigned long flags, unsigned long *begin,
99 unsigned long *end)
100{
101 if (!test_thread_flag(TIF_ADDR32) && (flags & MAP_32BIT)) {
102 unsigned long new_begin;
103 /* This is usually used needed to map code in small
104 model, so it needs to be in the first 31bit. Limit
105 it to that. This means we need to move the
106 unmapped base down for this case. This can give
107 conflicts with the heap, but we assume that glibc
108 malloc knows how to fall back to mmap. Give it 1GB
109 of playground for now. -AK */
110 *begin = 0x40000000;
111 *end = 0x80000000;
112 if (current->flags & PF_RANDOMIZE) {
113 new_begin = randomize_range(*begin, *begin + 0x02000000, 0);
114 if (new_begin)
115 *begin = new_begin;
116 }
117 } else {
118 *begin = TASK_UNMAPPED_BASE;
119 *end = TASK_SIZE;
120 }
121}
122
123unsigned long
124arch_get_unmapped_area(struct file *filp, unsigned long addr,
125 unsigned long len, unsigned long pgoff, unsigned long flags)
126{
127 struct mm_struct *mm = current->mm;
128 struct vm_area_struct *vma;
129 unsigned long start_addr;
130 unsigned long begin, end;
131
132 if (flags & MAP_FIXED)
133 return addr;
134
135 find_start_end(flags, &begin, &end);
136
137 if (len > end)
138 return -ENOMEM;
139
140 if (addr) {
141 addr = PAGE_ALIGN(addr);
142 vma = find_vma(mm, addr);
143 if (end - len >= addr &&
144 (!vma || addr + len <= vma->vm_start))
145 return addr;
146 }
147 if (((flags & MAP_32BIT) || test_thread_flag(TIF_ADDR32))
148 && len <= mm->cached_hole_size) {
149 mm->cached_hole_size = 0;
150 mm->free_area_cache = begin;
151 }
152 addr = mm->free_area_cache;
153 if (addr < begin)
154 addr = begin;
155 start_addr = addr;
156
157full_search:
158
159 addr = align_addr(addr, filp, 0);
160
161 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
162 /* At this point: (!vma || addr < vma->vm_end). */
163 if (end - len < addr) {
164 /*
165 * Start a new search - just in case we missed
166 * some holes.
167 */
168 if (start_addr != begin) {
169 start_addr = addr = begin;
170 mm->cached_hole_size = 0;
171 goto full_search;
172 }
173 return -ENOMEM;
174 }
175 if (!vma || addr + len <= vma->vm_start) {
176 /*
177 * Remember the place where we stopped the search:
178 */
179 mm->free_area_cache = addr + len;
180 return addr;
181 }
182 if (addr + mm->cached_hole_size < vma->vm_start)
183 mm->cached_hole_size = vma->vm_start - addr;
184
185 addr = vma->vm_end;
186 addr = align_addr(addr, filp, 0);
187 }
188}
189
190
191unsigned long
192arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
193 const unsigned long len, const unsigned long pgoff,
194 const unsigned long flags)
195{
196 struct vm_area_struct *vma;
197 struct mm_struct *mm = current->mm;
198 unsigned long addr = addr0, start_addr;
199
200 /* requested length too big for entire address space */
201 if (len > TASK_SIZE)
202 return -ENOMEM;
203
204 if (flags & MAP_FIXED)
205 return addr;
206
207 /* for MAP_32BIT mappings we force the legact mmap base */
208 if (!test_thread_flag(TIF_ADDR32) && (flags & MAP_32BIT))
209 goto bottomup;
210
211 /* requesting a specific address */
212 if (addr) {
213 addr = PAGE_ALIGN(addr);
214 vma = find_vma(mm, addr);
215 if (TASK_SIZE - len >= addr &&
216 (!vma || addr + len <= vma->vm_start))
217 return addr;
218 }
219
220 /* check if free_area_cache is useful for us */
221 if (len <= mm->cached_hole_size) {
222 mm->cached_hole_size = 0;
223 mm->free_area_cache = mm->mmap_base;
224 }
225
226try_again:
227 /* either no address requested or can't fit in requested address hole */
228 start_addr = addr = mm->free_area_cache;
229
230 if (addr < len)
231 goto fail;
232
233 addr -= len;
234 do {
235 addr = align_addr(addr, filp, ALIGN_TOPDOWN);
236
237 /*
238 * Lookup failure means no vma is above this address,
239 * else if new region fits below vma->vm_start,
240 * return with success:
241 */
242 vma = find_vma(mm, addr);
243 if (!vma || addr+len <= vma->vm_start)
244 /* remember the address as a hint for next time */
245 return mm->free_area_cache = addr;
246
247 /* remember the largest hole we saw so far */
248 if (addr + mm->cached_hole_size < vma->vm_start)
249 mm->cached_hole_size = vma->vm_start - addr;
250
251 /* try just below the current vma->vm_start */
252 addr = vma->vm_start-len;
253 } while (len < vma->vm_start);
254
255fail:
256 /*
257 * if hint left us with no space for the requested
258 * mapping then try again:
259 */
260 if (start_addr != mm->mmap_base) {
261 mm->free_area_cache = mm->mmap_base;
262 mm->cached_hole_size = 0;
263 goto try_again;
264 }
265
266bottomup:
267 /*
268 * A failed mmap() very likely causes application failure,
269 * so fall back to the bottom-up function here. This scenario
270 * can happen with large stack limits and large mmap()
271 * allocations.
272 */
273 mm->cached_hole_size = ~0UL;
274 mm->free_area_cache = TASK_UNMAPPED_BASE;
275 addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
276 /*
277 * Restore the topdown base:
278 */
279 mm->free_area_cache = mm->mmap_base;
280 mm->cached_hole_size = ~0UL;
281
282 return addr;
283}
1#include <linux/errno.h>
2#include <linux/sched.h>
3#include <linux/syscalls.h>
4#include <linux/mm.h>
5#include <linux/fs.h>
6#include <linux/smp.h>
7#include <linux/sem.h>
8#include <linux/msg.h>
9#include <linux/shm.h>
10#include <linux/stat.h>
11#include <linux/mman.h>
12#include <linux/file.h>
13#include <linux/utsname.h>
14#include <linux/personality.h>
15#include <linux/random.h>
16#include <linux/uaccess.h>
17
18#include <asm/ia32.h>
19#include <asm/syscalls.h>
20
21SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
22 unsigned long, prot, unsigned long, flags,
23 unsigned long, fd, unsigned long, off)
24{
25 long error;
26 error = -EINVAL;
27 if (off & ~PAGE_MASK)
28 goto out;
29
30 error = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
31out:
32 return error;
33}
34
35static void find_start_end(unsigned long flags, unsigned long *begin,
36 unsigned long *end)
37{
38 if (!test_thread_flag(TIF_IA32) && (flags & MAP_32BIT)) {
39 unsigned long new_begin;
40 /* This is usually used needed to map code in small
41 model, so it needs to be in the first 31bit. Limit
42 it to that. This means we need to move the
43 unmapped base down for this case. This can give
44 conflicts with the heap, but we assume that glibc
45 malloc knows how to fall back to mmap. Give it 1GB
46 of playground for now. -AK */
47 *begin = 0x40000000;
48 *end = 0x80000000;
49 if (current->flags & PF_RANDOMIZE) {
50 new_begin = randomize_range(*begin, *begin + 0x02000000, 0);
51 if (new_begin)
52 *begin = new_begin;
53 }
54 } else {
55 *begin = TASK_UNMAPPED_BASE;
56 *end = TASK_SIZE;
57 }
58}
59
60unsigned long
61arch_get_unmapped_area(struct file *filp, unsigned long addr,
62 unsigned long len, unsigned long pgoff, unsigned long flags)
63{
64 struct mm_struct *mm = current->mm;
65 struct vm_area_struct *vma;
66 unsigned long start_addr;
67 unsigned long begin, end;
68
69 if (flags & MAP_FIXED)
70 return addr;
71
72 find_start_end(flags, &begin, &end);
73
74 if (len > end)
75 return -ENOMEM;
76
77 if (addr) {
78 addr = PAGE_ALIGN(addr);
79 vma = find_vma(mm, addr);
80 if (end - len >= addr &&
81 (!vma || addr + len <= vma->vm_start))
82 return addr;
83 }
84 if (((flags & MAP_32BIT) || test_thread_flag(TIF_IA32))
85 && len <= mm->cached_hole_size) {
86 mm->cached_hole_size = 0;
87 mm->free_area_cache = begin;
88 }
89 addr = mm->free_area_cache;
90 if (addr < begin)
91 addr = begin;
92 start_addr = addr;
93
94full_search:
95 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
96 /* At this point: (!vma || addr < vma->vm_end). */
97 if (end - len < addr) {
98 /*
99 * Start a new search - just in case we missed
100 * some holes.
101 */
102 if (start_addr != begin) {
103 start_addr = addr = begin;
104 mm->cached_hole_size = 0;
105 goto full_search;
106 }
107 return -ENOMEM;
108 }
109 if (!vma || addr + len <= vma->vm_start) {
110 /*
111 * Remember the place where we stopped the search:
112 */
113 mm->free_area_cache = addr + len;
114 return addr;
115 }
116 if (addr + mm->cached_hole_size < vma->vm_start)
117 mm->cached_hole_size = vma->vm_start - addr;
118
119 addr = vma->vm_end;
120 }
121}
122
123
124unsigned long
125arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
126 const unsigned long len, const unsigned long pgoff,
127 const unsigned long flags)
128{
129 struct vm_area_struct *vma;
130 struct mm_struct *mm = current->mm;
131 unsigned long addr = addr0;
132
133 /* requested length too big for entire address space */
134 if (len > TASK_SIZE)
135 return -ENOMEM;
136
137 if (flags & MAP_FIXED)
138 return addr;
139
140 /* for MAP_32BIT mappings we force the legact mmap base */
141 if (!test_thread_flag(TIF_IA32) && (flags & MAP_32BIT))
142 goto bottomup;
143
144 /* requesting a specific address */
145 if (addr) {
146 addr = PAGE_ALIGN(addr);
147 vma = find_vma(mm, addr);
148 if (TASK_SIZE - len >= addr &&
149 (!vma || addr + len <= vma->vm_start))
150 return addr;
151 }
152
153 /* check if free_area_cache is useful for us */
154 if (len <= mm->cached_hole_size) {
155 mm->cached_hole_size = 0;
156 mm->free_area_cache = mm->mmap_base;
157 }
158
159 /* either no address requested or can't fit in requested address hole */
160 addr = mm->free_area_cache;
161
162 /* make sure it can fit in the remaining address space */
163 if (addr > len) {
164 vma = find_vma(mm, addr-len);
165 if (!vma || addr <= vma->vm_start)
166 /* remember the address as a hint for next time */
167 return mm->free_area_cache = addr-len;
168 }
169
170 if (mm->mmap_base < len)
171 goto bottomup;
172
173 addr = mm->mmap_base-len;
174
175 do {
176 /*
177 * Lookup failure means no vma is above this address,
178 * else if new region fits below vma->vm_start,
179 * return with success:
180 */
181 vma = find_vma(mm, addr);
182 if (!vma || addr+len <= vma->vm_start)
183 /* remember the address as a hint for next time */
184 return mm->free_area_cache = addr;
185
186 /* remember the largest hole we saw so far */
187 if (addr + mm->cached_hole_size < vma->vm_start)
188 mm->cached_hole_size = vma->vm_start - addr;
189
190 /* try just below the current vma->vm_start */
191 addr = vma->vm_start-len;
192 } while (len < vma->vm_start);
193
194bottomup:
195 /*
196 * A failed mmap() very likely causes application failure,
197 * so fall back to the bottom-up function here. This scenario
198 * can happen with large stack limits and large mmap()
199 * allocations.
200 */
201 mm->cached_hole_size = ~0UL;
202 mm->free_area_cache = TASK_UNMAPPED_BASE;
203 addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
204 /*
205 * Restore the topdown base:
206 */
207 mm->free_area_cache = mm->mmap_base;
208 mm->cached_hole_size = ~0UL;
209
210 return addr;
211}