xref: /openbmc/linux/arch/parisc/kernel/sys_parisc.c (revision 7f6964c5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 /*
4  *    PARISC specific syscalls
5  *
6  *    Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
7  *    Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
8  *    Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
9  *    Copyright (C) 1999-2014 Helge Deller <deller@gmx.de>
10  */
11 
12 #include <linux/uaccess.h>
13 #include <asm/elf.h>
14 #include <linux/file.h>
15 #include <linux/fs.h>
16 #include <linux/linkage.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/sched/signal.h>
20 #include <linux/sched/mm.h>
21 #include <linux/shm.h>
22 #include <linux/syscalls.h>
23 #include <linux/utsname.h>
24 #include <linux/personality.h>
25 #include <linux/random.h>
26 
27 /* we construct an artificial offset for the mapping based on the physical
28  * address of the kernel mapping variable */
29 #define GET_LAST_MMAP(filp)		\
30 	(filp ? ((unsigned long) filp->f_mapping) >> 8 : 0UL)
31 #define SET_LAST_MMAP(filp, val)	\
32 	 { /* nothing */ }
33 
34 static int get_offset(unsigned int last_mmap)
35 {
36 	return (last_mmap & (SHM_COLOUR-1)) >> PAGE_SHIFT;
37 }
38 
39 static unsigned long shared_align_offset(unsigned int last_mmap,
40 					 unsigned long pgoff)
41 {
42 	return (get_offset(last_mmap) + pgoff) << PAGE_SHIFT;
43 }
44 
45 static inline unsigned long COLOR_ALIGN(unsigned long addr,
46 			 unsigned int last_mmap, unsigned long pgoff)
47 {
48 	unsigned long base = (addr+SHM_COLOUR-1) & ~(SHM_COLOUR-1);
49 	unsigned long off  = (SHM_COLOUR-1) &
50 		(shared_align_offset(last_mmap, pgoff) << PAGE_SHIFT);
51 
52 	return base + off;
53 }
54 
55 /*
56  * Top of mmap area (just below the process stack).
57  */
58 
59 /*
60  * When called from arch_get_unmapped_area(), rlim_stack will be NULL,
61  * indicating that "current" should be used instead of a passed-in
62  * value from the exec bprm as done with arch_pick_mmap_layout().
63  */
64 static unsigned long mmap_upper_limit(struct rlimit *rlim_stack)
65 {
66 	unsigned long stack_base;
67 
68 	/* Limit stack size - see setup_arg_pages() in fs/exec.c */
69 	stack_base = rlim_stack ? rlim_stack->rlim_max
70 				: rlimit_max(RLIMIT_STACK);
71 	if (stack_base > STACK_SIZE_MAX)
72 		stack_base = STACK_SIZE_MAX;
73 
74 	/* Add space for stack randomization. */
75 	if (current->flags & PF_RANDOMIZE)
76 		stack_base += (STACK_RND_MASK << PAGE_SHIFT);
77 
78 	return PAGE_ALIGN(STACK_TOP - stack_base);
79 }
80 
81 
82 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
83 		unsigned long len, unsigned long pgoff, unsigned long flags)
84 {
85 	struct mm_struct *mm = current->mm;
86 	struct vm_area_struct *vma, *prev;
87 	unsigned long task_size = TASK_SIZE;
88 	int do_color_align, last_mmap;
89 	struct vm_unmapped_area_info info;
90 
91 	if (len > task_size)
92 		return -ENOMEM;
93 
94 	do_color_align = 0;
95 	if (filp || (flags & MAP_SHARED))
96 		do_color_align = 1;
97 	last_mmap = GET_LAST_MMAP(filp);
98 
99 	if (flags & MAP_FIXED) {
100 		if ((flags & MAP_SHARED) && last_mmap &&
101 		    (addr - shared_align_offset(last_mmap, pgoff))
102 				& (SHM_COLOUR - 1))
103 			return -EINVAL;
104 		goto found_addr;
105 	}
106 
107 	if (addr) {
108 		if (do_color_align && last_mmap)
109 			addr = COLOR_ALIGN(addr, last_mmap, pgoff);
110 		else
111 			addr = PAGE_ALIGN(addr);
112 
113 		vma = find_vma_prev(mm, addr, &prev);
114 		if (task_size - len >= addr &&
115 		    (!vma || addr + len <= vm_start_gap(vma)) &&
116 		    (!prev || addr >= vm_end_gap(prev)))
117 			goto found_addr;
118 	}
119 
120 	info.flags = 0;
121 	info.length = len;
122 	info.low_limit = mm->mmap_legacy_base;
123 	info.high_limit = mmap_upper_limit(NULL);
124 	info.align_mask = last_mmap ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0;
125 	info.align_offset = shared_align_offset(last_mmap, pgoff);
126 	addr = vm_unmapped_area(&info);
127 
128 found_addr:
129 	if (do_color_align && !last_mmap && !(addr & ~PAGE_MASK))
130 		SET_LAST_MMAP(filp, addr - (pgoff << PAGE_SHIFT));
131 
132 	return addr;
133 }
134 
135 unsigned long
136 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
137 			  const unsigned long len, const unsigned long pgoff,
138 			  const unsigned long flags)
139 {
140 	struct vm_area_struct *vma, *prev;
141 	struct mm_struct *mm = current->mm;
142 	unsigned long addr = addr0;
143 	int do_color_align, last_mmap;
144 	struct vm_unmapped_area_info info;
145 
146 	/* requested length too big for entire address space */
147 	if (len > TASK_SIZE)
148 		return -ENOMEM;
149 
150 	do_color_align = 0;
151 	if (filp || (flags & MAP_SHARED))
152 		do_color_align = 1;
153 	last_mmap = GET_LAST_MMAP(filp);
154 
155 	if (flags & MAP_FIXED) {
156 		if ((flags & MAP_SHARED) && last_mmap &&
157 		    (addr - shared_align_offset(last_mmap, pgoff))
158 			& (SHM_COLOUR - 1))
159 			return -EINVAL;
160 		goto found_addr;
161 	}
162 
163 	/* requesting a specific address */
164 	if (addr) {
165 		if (do_color_align && last_mmap)
166 			addr = COLOR_ALIGN(addr, last_mmap, pgoff);
167 		else
168 			addr = PAGE_ALIGN(addr);
169 
170 		vma = find_vma_prev(mm, addr, &prev);
171 		if (TASK_SIZE - len >= addr &&
172 		    (!vma || addr + len <= vm_start_gap(vma)) &&
173 		    (!prev || addr >= vm_end_gap(prev)))
174 			goto found_addr;
175 	}
176 
177 	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
178 	info.length = len;
179 	info.low_limit = PAGE_SIZE;
180 	info.high_limit = mm->mmap_base;
181 	info.align_mask = last_mmap ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0;
182 	info.align_offset = shared_align_offset(last_mmap, pgoff);
183 	addr = vm_unmapped_area(&info);
184 	if (!(addr & ~PAGE_MASK))
185 		goto found_addr;
186 	VM_BUG_ON(addr != -ENOMEM);
187 
188 	/*
189 	 * A failed mmap() very likely causes application failure,
190 	 * so fall back to the bottom-up function here. This scenario
191 	 * can happen with large stack limits and large mmap()
192 	 * allocations.
193 	 */
194 	return arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
195 
196 found_addr:
197 	if (do_color_align && !last_mmap && !(addr & ~PAGE_MASK))
198 		SET_LAST_MMAP(filp, addr - (pgoff << PAGE_SHIFT));
199 
200 	return addr;
201 }
202 
203 static int mmap_is_legacy(void)
204 {
205 	if (current->personality & ADDR_COMPAT_LAYOUT)
206 		return 1;
207 
208 	/* parisc stack always grows up - so a unlimited stack should
209 	 * not be an indicator to use the legacy memory layout.
210 	 * if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
211 	 *	return 1;
212 	 */
213 
214 	return sysctl_legacy_va_layout;
215 }
216 
217 static unsigned long mmap_rnd(void)
218 {
219 	unsigned long rnd = 0;
220 
221 	if (current->flags & PF_RANDOMIZE)
222 		rnd = get_random_int() & MMAP_RND_MASK;
223 
224 	return rnd << PAGE_SHIFT;
225 }
226 
227 unsigned long arch_mmap_rnd(void)
228 {
229 	return (get_random_int() & MMAP_RND_MASK) << PAGE_SHIFT;
230 }
231 
232 static unsigned long mmap_legacy_base(void)
233 {
234 	return TASK_UNMAPPED_BASE + mmap_rnd();
235 }
236 
237 /*
238  * This function, called very early during the creation of a new
239  * process VM image, sets up which VM layout function to use:
240  */
241 void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
242 {
243 	mm->mmap_legacy_base = mmap_legacy_base();
244 	mm->mmap_base = mmap_upper_limit(rlim_stack);
245 
246 	if (mmap_is_legacy()) {
247 		mm->mmap_base = mm->mmap_legacy_base;
248 		mm->get_unmapped_area = arch_get_unmapped_area;
249 	} else {
250 		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
251 	}
252 }
253 
254 
255 asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
256 	unsigned long prot, unsigned long flags, unsigned long fd,
257 	unsigned long pgoff)
258 {
259 	/* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
260 	   we have. */
261 	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
262 			       pgoff >> (PAGE_SHIFT - 12));
263 }
264 
265 asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
266 		unsigned long prot, unsigned long flags, unsigned long fd,
267 		unsigned long offset)
268 {
269 	if (!(offset & ~PAGE_MASK)) {
270 		return ksys_mmap_pgoff(addr, len, prot, flags, fd,
271 					offset >> PAGE_SHIFT);
272 	} else {
273 		return -EINVAL;
274 	}
275 }
276 
277 /* Fucking broken ABI */
278 
279 #ifdef CONFIG_64BIT
280 asmlinkage long parisc_truncate64(const char __user * path,
281 					unsigned int high, unsigned int low)
282 {
283 	return ksys_truncate(path, (long)high << 32 | low);
284 }
285 
286 asmlinkage long parisc_ftruncate64(unsigned int fd,
287 					unsigned int high, unsigned int low)
288 {
289 	return ksys_ftruncate(fd, (long)high << 32 | low);
290 }
291 
292 /* stubs for the benefit of the syscall_table since truncate64 and truncate
293  * are identical on LP64 */
294 asmlinkage long sys_truncate64(const char __user * path, unsigned long length)
295 {
296 	return ksys_truncate(path, length);
297 }
298 asmlinkage long sys_ftruncate64(unsigned int fd, unsigned long length)
299 {
300 	return ksys_ftruncate(fd, length);
301 }
302 asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
303 {
304 	return sys_fcntl(fd, cmd, arg);
305 }
306 #else
307 
308 asmlinkage long parisc_truncate64(const char __user * path,
309 					unsigned int high, unsigned int low)
310 {
311 	return ksys_truncate(path, (loff_t)high << 32 | low);
312 }
313 
314 asmlinkage long parisc_ftruncate64(unsigned int fd,
315 					unsigned int high, unsigned int low)
316 {
317 	return sys_ftruncate64(fd, (loff_t)high << 32 | low);
318 }
319 #endif
320 
321 asmlinkage ssize_t parisc_pread64(unsigned int fd, char __user *buf, size_t count,
322 					unsigned int high, unsigned int low)
323 {
324 	return ksys_pread64(fd, buf, count, (loff_t)high << 32 | low);
325 }
326 
327 asmlinkage ssize_t parisc_pwrite64(unsigned int fd, const char __user *buf,
328 			size_t count, unsigned int high, unsigned int low)
329 {
330 	return ksys_pwrite64(fd, buf, count, (loff_t)high << 32 | low);
331 }
332 
333 asmlinkage ssize_t parisc_readahead(int fd, unsigned int high, unsigned int low,
334 		                    size_t count)
335 {
336 	return ksys_readahead(fd, (loff_t)high << 32 | low, count);
337 }
338 
339 asmlinkage long parisc_fadvise64_64(int fd,
340 			unsigned int high_off, unsigned int low_off,
341 			unsigned int high_len, unsigned int low_len, int advice)
342 {
343 	return ksys_fadvise64_64(fd, (loff_t)high_off << 32 | low_off,
344 			(loff_t)high_len << 32 | low_len, advice);
345 }
346 
347 asmlinkage long parisc_sync_file_range(int fd,
348 			u32 hi_off, u32 lo_off, u32 hi_nbytes, u32 lo_nbytes,
349 			unsigned int flags)
350 {
351 	return ksys_sync_file_range(fd, (loff_t)hi_off << 32 | lo_off,
352 			(loff_t)hi_nbytes << 32 | lo_nbytes, flags);
353 }
354 
355 asmlinkage long parisc_fallocate(int fd, int mode, u32 offhi, u32 offlo,
356 				u32 lenhi, u32 lenlo)
357 {
358 	return ksys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
359 			      ((u64)lenhi << 32) | lenlo);
360 }
361 
362 long parisc_personality(unsigned long personality)
363 {
364 	long err;
365 
366 	if (personality(current->personality) == PER_LINUX32
367 	    && personality(personality) == PER_LINUX)
368 		personality = (personality & ~PER_MASK) | PER_LINUX32;
369 
370 	err = sys_personality(personality);
371 	if (personality(err) == PER_LINUX32)
372 		err = (err & ~PER_MASK) | PER_LINUX;
373 
374 	return err;
375 }
376