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authorCatalin Marinas <catalin.marinas@arm.com>2012-03-05 06:49:27 -0500
committerCatalin Marinas <catalin.marinas@arm.com>2012-09-17 08:41:57 -0400
commit1d18c47c735e8adfe531fc41fae31e98f86b68fe (patch)
treeb63f253304e2d955e1a17d12e4f0dc94312f58ea /arch/arm64
parentc1cc1552616d0f354d040823151e61634e7ad01f (diff)
arm64: MMU fault handling and page table management
This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/page.h67
-rw-r--r--arch/arm64/include/asm/pgalloc.h113
-rw-r--r--arch/arm64/mm/copypage.c34
-rw-r--r--arch/arm64/mm/extable.c17
-rw-r--r--arch/arm64/mm/fault.c534
-rw-r--r--arch/arm64/mm/mm.h2
-rw-r--r--arch/arm64/mm/mmap.c144
-rw-r--r--arch/arm64/mm/pgd.c54
8 files changed, 965 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h
new file mode 100644
index 000000000000..46bf66628b6a
--- /dev/null
+++ b/arch/arm64/include/asm/page.h
@@ -0,0 +1,67 @@
1/*
2 * Based on arch/arm/include/asm/page.h
3 *
4 * Copyright (C) 1995-2003 Russell King
5 * Copyright (C) 2012 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19#ifndef __ASM_PAGE_H
20#define __ASM_PAGE_H
21
22/* PAGE_SHIFT determines the page size */
23#ifdef CONFIG_ARM64_64K_PAGES
24#define PAGE_SHIFT 16
25#else
26#define PAGE_SHIFT 12
27#endif
28#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
29#define PAGE_MASK (~(PAGE_SIZE-1))
30
31/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
32#define __HAVE_ARCH_GATE_AREA 1
33
34#ifndef __ASSEMBLY__
35
36#ifdef CONFIG_ARM64_64K_PAGES
37#include <asm/pgtable-2level-types.h>
38#else
39#include <asm/pgtable-3level-types.h>
40#endif
41
42extern void __cpu_clear_user_page(void *p, unsigned long user);
43extern void __cpu_copy_user_page(void *to, const void *from,
44 unsigned long user);
45extern void copy_page(void *to, const void *from);
46extern void clear_page(void *to);
47
48#define clear_user_page(addr,vaddr,pg) __cpu_clear_user_page(addr, vaddr)
49#define copy_user_page(to,from,vaddr,pg) __cpu_copy_user_page(to, from, vaddr)
50
51typedef struct page *pgtable_t;
52
53#ifdef CONFIG_HAVE_ARCH_PFN_VALID
54extern int pfn_valid(unsigned long);
55#endif
56
57#include <asm/memory.h>
58
59#endif /* !__ASSEMBLY__ */
60
61#define VM_DATA_DEFAULT_FLAGS \
62 (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) | \
63 VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
64
65#include <asm-generic/getorder.h>
66
67#endif
diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
new file mode 100644
index 000000000000..f214069ec5d5
--- /dev/null
+++ b/arch/arm64/include/asm/pgalloc.h
@@ -0,0 +1,113 @@
1/*
2 * Based on arch/arm/include/asm/pgalloc.h
3 *
4 * Copyright (C) 2000-2001 Russell King
5 * Copyright (C) 2012 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19#ifndef __ASM_PGALLOC_H
20#define __ASM_PGALLOC_H
21
22#include <asm/pgtable-hwdef.h>
23#include <asm/processor.h>
24#include <asm/cacheflush.h>
25#include <asm/tlbflush.h>
26
27#define check_pgt_cache() do { } while (0)
28
29#ifndef CONFIG_ARM64_64K_PAGES
30
31static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
32{
33 return (pmd_t *)get_zeroed_page(GFP_KERNEL | __GFP_REPEAT);
34}
35
36static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
37{
38 BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
39 free_page((unsigned long)pmd);
40}
41
42static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
43{
44 set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
45}
46
47#endif /* CONFIG_ARM64_64K_PAGES */
48
49extern pgd_t *pgd_alloc(struct mm_struct *mm);
50extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
51
52#define PGALLOC_GFP (GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO)
53
54static inline pte_t *
55pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
56{
57 return (pte_t *)__get_free_page(PGALLOC_GFP);
58}
59
60static inline pgtable_t
61pte_alloc_one(struct mm_struct *mm, unsigned long addr)
62{
63 struct page *pte;
64
65 pte = alloc_pages(PGALLOC_GFP, 0);
66 if (pte)
67 pgtable_page_ctor(pte);
68
69 return pte;
70}
71
72/*
73 * Free a PTE table.
74 */
75static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
76{
77 if (pte)
78 free_page((unsigned long)pte);
79}
80
81static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
82{
83 pgtable_page_dtor(pte);
84 __free_page(pte);
85}
86
87static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
88 pmdval_t prot)
89{
90 set_pmd(pmdp, __pmd(pte | prot));
91}
92
93/*
94 * Populate the pmdp entry with a pointer to the pte. This pmd is part
95 * of the mm address space.
96 */
97static inline void
98pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
99{
100 /*
101 * The pmd must be loaded with the physical address of the PTE table
102 */
103 __pmd_populate(pmdp, __pa(ptep), PMD_TYPE_TABLE);
104}
105
106static inline void
107pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
108{
109 __pmd_populate(pmdp, page_to_phys(ptep), PMD_TYPE_TABLE);
110}
111#define pmd_pgtable(pmd) pmd_page(pmd)
112
113#endif
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
new file mode 100644
index 000000000000..9aecbace4128
--- /dev/null
+++ b/arch/arm64/mm/copypage.c
@@ -0,0 +1,34 @@
1/*
2 * Based on arch/arm/mm/copypage.c
3 *
4 * Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved.
5 * Copyright (C) 2012 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/mm.h>
21
22#include <asm/page.h>
23#include <asm/cacheflush.h>
24
25void __cpu_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
26{
27 copy_page(kto, kfrom);
28 __flush_dcache_area(kto, PAGE_SIZE);
29}
30
31void __cpu_clear_user_page(void *kaddr, unsigned long vaddr)
32{
33 clear_page(kaddr);
34}
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
new file mode 100644
index 000000000000..79444279ba8c
--- /dev/null
+++ b/arch/arm64/mm/extable.c
@@ -0,0 +1,17 @@
1/*
2 * Based on arch/arm/mm/extable.c
3 */
4
5#include <linux/module.h>
6#include <linux/uaccess.h>
7
8int fixup_exception(struct pt_regs *regs)
9{
10 const struct exception_table_entry *fixup;
11
12 fixup = search_exception_tables(instruction_pointer(regs));
13 if (fixup)
14 regs->pc = fixup->fixup;
15
16 return fixup != NULL;
17}
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
new file mode 100644
index 000000000000..1909a69983ca
--- /dev/null
+++ b/arch/arm64/mm/fault.c
@@ -0,0 +1,534 @@
1/*
2 * Based on arch/arm/mm/fault.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 * Copyright (C) 1995-2004 Russell King
6 * Copyright (C) 2012 ARM Ltd.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21#include <linux/module.h>
22#include <linux/signal.h>
23#include <linux/mm.h>
24#include <linux/hardirq.h>
25#include <linux/init.h>
26#include <linux/kprobes.h>
27#include <linux/uaccess.h>
28#include <linux/page-flags.h>
29#include <linux/sched.h>
30#include <linux/highmem.h>
31#include <linux/perf_event.h>
32
33#include <asm/exception.h>
34#include <asm/debug-monitors.h>
35#include <asm/system_misc.h>
36#include <asm/pgtable.h>
37#include <asm/tlbflush.h>
38
39/*
40 * Dump out the page tables associated with 'addr' in mm 'mm'.
41 */
42void show_pte(struct mm_struct *mm, unsigned long addr)
43{
44 pgd_t *pgd;
45
46 if (!mm)
47 mm = &init_mm;
48
49 pr_alert("pgd = %p\n", mm->pgd);
50 pgd = pgd_offset(mm, addr);
51 pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd));
52
53 do {
54 pud_t *pud;
55 pmd_t *pmd;
56 pte_t *pte;
57
58 if (pgd_none_or_clear_bad(pgd))
59 break;
60
61 pud = pud_offset(pgd, addr);
62 if (pud_none_or_clear_bad(pud))
63 break;
64
65 pmd = pmd_offset(pud, addr);
66 printk(", *pmd=%016llx", pmd_val(*pmd));
67 if (pmd_none_or_clear_bad(pmd))
68 break;
69
70 pte = pte_offset_map(pmd, addr);
71 printk(", *pte=%016llx", pte_val(*pte));
72 pte_unmap(pte);
73 } while(0);
74
75 printk("\n");
76}
77
78/*
79 * The kernel tried to access some page that wasn't present.
80 */
81static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr,
82 unsigned int esr, struct pt_regs *regs)
83{
84 /*
85 * Are we prepared to handle this kernel fault?
86 */
87 if (fixup_exception(regs))
88 return;
89
90 /*
91 * No handler, we'll have to terminate things with extreme prejudice.
92 */
93 bust_spinlocks(1);
94 pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
95 (addr < PAGE_SIZE) ? "NULL pointer dereference" :
96 "paging request", addr);
97
98 show_pte(mm, addr);
99 die("Oops", regs, esr);
100 bust_spinlocks(0);
101 do_exit(SIGKILL);
102}
103
104/*
105 * Something tried to access memory that isn't in our memory map. User mode
106 * accesses just cause a SIGSEGV
107 */
108static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
109 unsigned int esr, unsigned int sig, int code,
110 struct pt_regs *regs)
111{
112 struct siginfo si;
113
114 if (show_unhandled_signals) {
115 pr_info("%s[%d]: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n",
116 tsk->comm, task_pid_nr(tsk), sig, addr, esr);
117 show_pte(tsk->mm, addr);
118 show_regs(regs);
119 }
120
121 tsk->thread.fault_address = addr;
122 si.si_signo = sig;
123 si.si_errno = 0;
124 si.si_code = code;
125 si.si_addr = (void __user *)addr;
126 force_sig_info(sig, &si, tsk);
127}
128
129void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
130{
131 struct task_struct *tsk = current;
132 struct mm_struct *mm = tsk->active_mm;
133
134 /*
135 * If we are in kernel mode at this point, we have no context to
136 * handle this fault with.
137 */
138 if (user_mode(regs))
139 __do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs);
140 else
141 __do_kernel_fault(mm, addr, esr, regs);
142}
143
144#define VM_FAULT_BADMAP 0x010000
145#define VM_FAULT_BADACCESS 0x020000
146
147#define ESR_WRITE (1 << 6)
148#define ESR_LNX_EXEC (1 << 24)
149
150/*
151 * Check that the permissions on the VMA allow for the fault which occurred.
152 * If we encountered a write fault, we must have write permission, otherwise
153 * we allow any permission.
154 */
155static inline bool access_error(unsigned int esr, struct vm_area_struct *vma)
156{
157 unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
158
159 if (esr & ESR_WRITE)
160 mask = VM_WRITE;
161 if (esr & ESR_LNX_EXEC)
162 mask = VM_EXEC;
163
164 return vma->vm_flags & mask ? false : true;
165}
166
167static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
168 unsigned int esr, unsigned int flags,
169 struct task_struct *tsk)
170{
171 struct vm_area_struct *vma;
172 int fault;
173
174 vma = find_vma(mm, addr);
175 fault = VM_FAULT_BADMAP;
176 if (unlikely(!vma))
177 goto out;
178 if (unlikely(vma->vm_start > addr))
179 goto check_stack;
180
181 /*
182 * Ok, we have a good vm_area for this memory access, so we can handle
183 * it.
184 */
185good_area:
186 if (access_error(esr, vma)) {
187 fault = VM_FAULT_BADACCESS;
188 goto out;
189 }
190
191 return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags);
192
193check_stack:
194 if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
195 goto good_area;
196out:
197 return fault;
198}
199
200static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
201 struct pt_regs *regs)
202{
203 struct task_struct *tsk;
204 struct mm_struct *mm;
205 int fault, sig, code;
206 int write = esr & ESR_WRITE;
207 unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
208 (write ? FAULT_FLAG_WRITE : 0);
209
210 tsk = current;
211 mm = tsk->mm;
212
213 /* Enable interrupts if they were enabled in the parent context. */
214 if (interrupts_enabled(regs))
215 local_irq_enable();
216
217 /*
218 * If we're in an interrupt or have no user context, we must not take
219 * the fault.
220 */
221 if (in_atomic() || !mm)
222 goto no_context;
223
224 /*
225 * As per x86, we may deadlock here. However, since the kernel only
226 * validly references user space from well defined areas of the code,
227 * we can bug out early if this is from code which shouldn't.
228 */
229 if (!down_read_trylock(&mm->mmap_sem)) {
230 if (!user_mode(regs) && !search_exception_tables(regs->pc))
231 goto no_context;
232retry:
233 down_read(&mm->mmap_sem);
234 } else {
235 /*
236 * The above down_read_trylock() might have succeeded in which
237 * case, we'll have missed the might_sleep() from down_read().
238 */
239 might_sleep();
240#ifdef CONFIG_DEBUG_VM
241 if (!user_mode(regs) && !search_exception_tables(regs->pc))
242 goto no_context;
243#endif
244 }
245
246 fault = __do_page_fault(mm, addr, esr, flags, tsk);
247
248 /*
249 * If we need to retry but a fatal signal is pending, handle the
250 * signal first. We do not need to release the mmap_sem because it
251 * would already be released in __lock_page_or_retry in mm/filemap.c.
252 */
253 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
254 return 0;
255
256 /*
257 * Major/minor page fault accounting is only done on the initial
258 * attempt. If we go through a retry, it is extremely likely that the
259 * page will be found in page cache at that point.
260 */
261
262 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
263 if (flags & FAULT_FLAG_ALLOW_RETRY) {
264 if (fault & VM_FAULT_MAJOR) {
265 tsk->maj_flt++;
266 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
267 addr);
268 } else {
269 tsk->min_flt++;
270 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
271 addr);
272 }
273 if (fault & VM_FAULT_RETRY) {
274 /*
275 * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
276 * starvation.
277 */
278 flags &= ~FAULT_FLAG_ALLOW_RETRY;
279 goto retry;
280 }
281 }
282
283 up_read(&mm->mmap_sem);
284
285 /*
286 * Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR
287 */
288 if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP |
289 VM_FAULT_BADACCESS))))
290 return 0;
291
292 if (fault & VM_FAULT_OOM) {
293 /*
294 * We ran out of memory, call the OOM killer, and return to
295 * userspace (which will retry the fault, or kill us if we got
296 * oom-killed).
297 */
298 pagefault_out_of_memory();
299 return 0;
300 }
301
302 /*
303 * If we are in kernel mode at this point, we have no context to
304 * handle this fault with.
305 */
306 if (!user_mode(regs))
307 goto no_context;
308
309 if (fault & VM_FAULT_SIGBUS) {
310 /*
311 * We had some memory, but were unable to successfully fix up
312 * this page fault.
313 */
314 sig = SIGBUS;
315 code = BUS_ADRERR;
316 } else {
317 /*
318 * Something tried to access memory that isn't in our memory
319 * map.
320 */
321 sig = SIGSEGV;
322 code = fault == VM_FAULT_BADACCESS ?
323 SEGV_ACCERR : SEGV_MAPERR;
324 }
325
326 __do_user_fault(tsk, addr, esr, sig, code, regs);
327 return 0;
328
329no_context:
330 __do_kernel_fault(mm, addr, esr, regs);
331 return 0;
332}
333
334/*
335 * First Level Translation Fault Handler
336 *
337 * We enter here because the first level page table doesn't contain a valid
338 * entry for the address.
339 *
340 * If the address is in kernel space (>= TASK_SIZE), then we are probably
341 * faulting in the vmalloc() area.
342 *
343 * If the init_task's first level page tables contains the relevant entry, we
344 * copy the it to this task. If not, we send the process a signal, fixup the
345 * exception, or oops the kernel.
346 *
347 * NOTE! We MUST NOT take any locks for this case. We may be in an interrupt
348 * or a critical region, and should only copy the information from the master
349 * page table, nothing more.
350 */
351static int __kprobes do_translation_fault(unsigned long addr,
352 unsigned int esr,
353 struct pt_regs *regs)
354{
355 if (addr < TASK_SIZE)
356 return do_page_fault(addr, esr, regs);
357
358 do_bad_area(addr, esr, regs);
359 return 0;
360}
361
362/*
363 * Some section permission faults need to be handled gracefully. They can
364 * happen due to a __{get,put}_user during an oops.
365 */
366static int do_sect_fault(unsigned long addr, unsigned int esr,
367 struct pt_regs *regs)
368{
369 do_bad_area(addr, esr, regs);
370 return 0;
371}
372
373/*
374 * This abort handler always returns "fault".
375 */
376static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
377{
378 return 1;
379}
380
381static struct fault_info {
382 int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs);
383 int sig;
384 int code;
385 const char *name;
386} fault_info[] = {
387 { do_bad, SIGBUS, 0, "ttbr address size fault" },
388 { do_bad, SIGBUS, 0, "level 1 address size fault" },
389 { do_bad, SIGBUS, 0, "level 2 address size fault" },
390 { do_bad, SIGBUS, 0, "level 3 address size fault" },
391 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "input address range fault" },
392 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" },
393 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
394 { do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
395 { do_bad, SIGBUS, 0, "reserved access flag fault" },
396 { do_bad, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
397 { do_bad, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
398 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
399 { do_bad, SIGBUS, 0, "reserved permission fault" },
400 { do_bad, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
401 { do_sect_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
402 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
403 { do_bad, SIGBUS, 0, "synchronous external abort" },
404 { do_bad, SIGBUS, 0, "asynchronous external abort" },
405 { do_bad, SIGBUS, 0, "unknown 18" },
406 { do_bad, SIGBUS, 0, "unknown 19" },
407 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
408 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
409 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
410 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" },
411 { do_bad, SIGBUS, 0, "synchronous parity error" },
412 { do_bad, SIGBUS, 0, "asynchronous parity error" },
413 { do_bad, SIGBUS, 0, "unknown 26" },
414 { do_bad, SIGBUS, 0, "unknown 27" },
415 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
416 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
417 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
418 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk" },
419 { do_bad, SIGBUS, 0, "unknown 32" },
420 { do_bad, SIGBUS, BUS_ADRALN, "alignment fault" },
421 { do_bad, SIGBUS, 0, "debug event" },
422 { do_bad, SIGBUS, 0, "unknown 35" },
423 { do_bad, SIGBUS, 0, "unknown 36" },
424 { do_bad, SIGBUS, 0, "unknown 37" },
425 { do_bad, SIGBUS, 0, "unknown 38" },
426 { do_bad, SIGBUS, 0, "unknown 39" },
427 { do_bad, SIGBUS, 0, "unknown 40" },
428 { do_bad, SIGBUS, 0, "unknown 41" },
429 { do_bad, SIGBUS, 0, "unknown 42" },
430 { do_bad, SIGBUS, 0, "unknown 43" },
431 { do_bad, SIGBUS, 0, "unknown 44" },
432 { do_bad, SIGBUS, 0, "unknown 45" },
433 { do_bad, SIGBUS, 0, "unknown 46" },
434 { do_bad, SIGBUS, 0, "unknown 47" },
435 { do_bad, SIGBUS, 0, "unknown 48" },
436 { do_bad, SIGBUS, 0, "unknown 49" },
437 { do_bad, SIGBUS, 0, "unknown 50" },
438 { do_bad, SIGBUS, 0, "unknown 51" },
439 { do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" },
440 { do_bad, SIGBUS, 0, "unknown 53" },
441 { do_bad, SIGBUS, 0, "unknown 54" },
442 { do_bad, SIGBUS, 0, "unknown 55" },
443 { do_bad, SIGBUS, 0, "unknown 56" },
444 { do_bad, SIGBUS, 0, "unknown 57" },
445 { do_bad, SIGBUS, 0, "implementation fault (coprocessor abort)" },
446 { do_bad, SIGBUS, 0, "unknown 59" },
447 { do_bad, SIGBUS, 0, "unknown 60" },
448 { do_bad, SIGBUS, 0, "unknown 61" },
449 { do_bad, SIGBUS, 0, "unknown 62" },
450 { do_bad, SIGBUS, 0, "unknown 63" },
451};
452
453/*
454 * Dispatch a data abort to the relevant handler.
455 */
456asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
457 struct pt_regs *regs)
458{
459 const struct fault_info *inf = fault_info + (esr & 63);
460 struct siginfo info;
461
462 if (!inf->fn(addr, esr, regs))
463 return;
464
465 pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n",
466 inf->name, esr, addr);
467
468 info.si_signo = inf->sig;
469 info.si_errno = 0;
470 info.si_code = inf->code;
471 info.si_addr = (void __user *)addr;
472 arm64_notify_die("", regs, &info, esr);
473}
474
475/*
476 * Handle stack alignment exceptions.
477 */
478asmlinkage void __exception do_sp_pc_abort(unsigned long addr,
479 unsigned int esr,
480 struct pt_regs *regs)
481{
482 struct siginfo info;
483
484 info.si_signo = SIGBUS;
485 info.si_errno = 0;
486 info.si_code = BUS_ADRALN;
487 info.si_addr = (void __user *)addr;
488 arm64_notify_die("", regs, &info, esr);
489}
490
491static struct fault_info debug_fault_info[] = {
492 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" },
493 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" },
494 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" },
495 { do_bad, SIGBUS, 0, "unknown 3" },
496 { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" },
497 { do_bad, SIGTRAP, 0, "aarch32 vector catch" },
498 { do_bad, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" },
499 { do_bad, SIGBUS, 0, "unknown 7" },
500};
501
502void __init hook_debug_fault_code(int nr,
503 int (*fn)(unsigned long, unsigned int, struct pt_regs *),
504 int sig, int code, const char *name)
505{
506 BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info));
507
508 debug_fault_info[nr].fn = fn;
509 debug_fault_info[nr].sig = sig;
510 debug_fault_info[nr].code = code;
511 debug_fault_info[nr].name = name;
512}
513
514asmlinkage int __exception do_debug_exception(unsigned long addr,
515 unsigned int esr,
516 struct pt_regs *regs)
517{
518 const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr);
519 struct siginfo info;
520
521 if (!inf->fn(addr, esr, regs))
522 return 1;
523
524 pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n",
525 inf->name, esr, addr);
526
527 info.si_signo = inf->sig;
528 info.si_errno = 0;
529 info.si_code = inf->code;
530 info.si_addr = (void __user *)addr;
531 arm64_notify_die("", regs, &info, esr);
532
533 return 0;
534}
diff --git a/arch/arm64/mm/mm.h b/arch/arm64/mm/mm.h
new file mode 100644
index 000000000000..d8d6e7851c14
--- /dev/null
+++ b/arch/arm64/mm/mm.h
@@ -0,0 +1,2 @@
1extern void __flush_dcache_page(struct page *page);
2extern void __init bootmem_init(void);
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
new file mode 100644
index 000000000000..7c7be7855638
--- /dev/null
+++ b/arch/arm64/mm/mmap.c
@@ -0,0 +1,144 @@
1/*
2 * Based on arch/arm/mm/mmap.c
3 *
4 * Copyright (C) 2012 ARM Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18
19#include <linux/elf.h>
20#include <linux/fs.h>
21#include <linux/mm.h>
22#include <linux/mman.h>
23#include <linux/export.h>
24#include <linux/shm.h>
25#include <linux/sched.h>
26#include <linux/io.h>
27#include <linux/personality.h>
28#include <linux/random.h>
29
30#include <asm/cputype.h>
31
32/*
33 * Leave enough space between the mmap area and the stack to honour ulimit in
34 * the face of randomisation.
35 */
36#define MIN_GAP (SZ_128M + ((STACK_RND_MASK << PAGE_SHIFT) + 1))
37#define MAX_GAP (STACK_TOP/6*5)
38
39static int mmap_is_legacy(void)
40{
41 if (current->personality & ADDR_COMPAT_LAYOUT)
42 return 1;
43
44 if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
45 return 1;
46
47 return sysctl_legacy_va_layout;
48}
49
50/*
51 * Since get_random_int() returns the same value within a 1 jiffy window, we
52 * will almost always get the same randomisation for the stack and mmap
53 * region. This will mean the relative distance between stack and mmap will be
54 * the same.
55 *
56 * To avoid this we can shift the randomness by 1 bit.
57 */
58static unsigned long mmap_rnd(void)
59{
60 unsigned long rnd = 0;
61
62 if (current->flags & PF_RANDOMIZE)
63 rnd = (long)get_random_int() & (STACK_RND_MASK >> 1);
64
65 return rnd << (PAGE_SHIFT + 1);
66}
67
68static unsigned long mmap_base(void)
69{
70 unsigned long gap = rlimit(RLIMIT_STACK);
71
72 if (gap < MIN_GAP)
73 gap = MIN_GAP;
74 else if (gap > MAX_GAP)
75 gap = MAX_GAP;
76
77 return PAGE_ALIGN(STACK_TOP - gap - mmap_rnd());
78}
79
80/*
81 * This function, called very early during the creation of a new process VM
82 * image, sets up which VM layout function to use:
83 */
84void arch_pick_mmap_layout(struct mm_struct *mm)
85{
86 /*
87 * Fall back to the standard layout if the personality bit is set, or
88 * if the expected stack growth is unlimited:
89 */
90 if (mmap_is_legacy()) {
91 mm->mmap_base = TASK_UNMAPPED_BASE;
92 mm->get_unmapped_area = arch_get_unmapped_area;
93 mm->unmap_area = arch_unmap_area;
94 } else {
95 mm->mmap_base = mmap_base();
96 mm->get_unmapped_area = arch_get_unmapped_area_topdown;
97 mm->unmap_area = arch_unmap_area_topdown;
98 }
99}
100EXPORT_SYMBOL_GPL(arch_pick_mmap_layout);
101
102
103/*
104 * You really shouldn't be using read() or write() on /dev/mem. This might go
105 * away in the future.
106 */
107int valid_phys_addr_range(unsigned long addr, size_t size)
108{
109 if (addr < PHYS_OFFSET)
110 return 0;
111 if (addr + size > __pa(high_memory - 1) + 1)
112 return 0;
113
114 return 1;
115}
116
117/*
118 * Do not allow /dev/mem mappings beyond the supported physical range.
119 */
120int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
121{
122 return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK);
123}
124
125#ifdef CONFIG_STRICT_DEVMEM
126
127#include <linux/ioport.h>
128
129/*
130 * devmem_is_allowed() checks to see if /dev/mem access to a certain address
131 * is valid. The argument is a physical page number. We mimic x86 here by
132 * disallowing access to system RAM as well as device-exclusive MMIO regions.
133 * This effectively disable read()/write() on /dev/mem.
134 */
135int devmem_is_allowed(unsigned long pfn)
136{
137 if (iomem_is_exclusive(pfn << PAGE_SHIFT))
138 return 0;
139 if (!page_is_ram(pfn))
140 return 1;
141 return 0;
142}
143
144#endif
diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c
new file mode 100644
index 000000000000..7083cdada657
--- /dev/null
+++ b/arch/arm64/mm/pgd.c
@@ -0,0 +1,54 @@
1/*
2 * PGD allocation/freeing
3 *
4 * Copyright (C) 2012 ARM Ltd.
5 * Author: Catalin Marinas <catalin.marinas@arm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/mm.h>
21#include <linux/gfp.h>
22#include <linux/highmem.h>
23#include <linux/slab.h>
24
25#include <asm/pgalloc.h>
26#include <asm/page.h>
27#include <asm/tlbflush.h>
28
29#include "mm.h"
30
31#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
32
33pgd_t *pgd_alloc(struct mm_struct *mm)
34{
35 pgd_t *new_pgd;
36
37 if (PGD_SIZE == PAGE_SIZE)
38 new_pgd = (pgd_t *)get_zeroed_page(GFP_KERNEL);
39 else
40 new_pgd = kzalloc(PGD_SIZE, GFP_KERNEL);
41
42 if (!new_pgd)
43 return NULL;
44
45 return new_pgd;
46}
47
48void pgd_free(struct mm_struct *mm, pgd_t *pgd)
49{
50 if (PGD_SIZE == PAGE_SIZE)
51 free_page((unsigned long)pgd);
52 else
53 kfree(pgd);
54}
generated by cgit v1.2.2 (git 2.25.0) at 2026-01-06 08:55:54 -0500