1 /*
2 * linux/arch/arm/kernel/process.c
3 *
4 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
5 * Original Copyright (C) 1995 Linus Torvalds
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 #include <stdarg.h>
12
13 #include <linux/export.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/mm.h>
17 #include <linux/stddef.h>
18 #include <linux/unistd.h>
19 #include <linux/user.h>
20 #include <linux/interrupt.h>
21 #include <linux/kallsyms.h>
22 #include <linux/init.h>
23 #include <linux/elfcore.h>
24 #include <linux/pm.h>
25 #include <linux/tick.h>
26 #include <linux/utsname.h>
27 #include <linux/uaccess.h>
28 #include <linux/random.h>
29 #include <linux/hw_breakpoint.h>
30 #include <linux/leds.h>
31
32 #include <asm/processor.h>
33 #include <asm/thread_notify.h>
34 #include <asm/stacktrace.h>
35 #include <asm/system_misc.h>
36 #include <asm/mach/time.h>
37 #include <asm/tls.h>
38 #include <asm/vdso.h>
39
40 #ifdef CONFIG_CC_STACKPROTECTOR
41 #include <linux/stackprotector.h>
42 unsigned long __stack_chk_guard __read_mostly;
43 EXPORT_SYMBOL(__stack_chk_guard);
44 #endif
45
46 static const char *processor_modes[] __maybe_unused = {
47 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
48 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
49 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "MON_32" , "ABT_32" ,
50 "UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
51 };
52
53 static const char *isa_modes[] __maybe_unused = {
54 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
55 };
56
57 /*
58 * This is our default idle handler.
59 */
60
61 void (*arm_pm_idle)(void);
62
63 /*
64 * Called from the core idle loop.
65 */
66
arch_cpu_idle(void)67 void arch_cpu_idle(void)
68 {
69 if (arm_pm_idle)
70 arm_pm_idle();
71 else
72 cpu_do_idle();
73 local_irq_enable();
74 }
75
arch_cpu_idle_prepare(void)76 void arch_cpu_idle_prepare(void)
77 {
78 local_fiq_enable();
79 }
80
arch_cpu_idle_enter(void)81 void arch_cpu_idle_enter(void)
82 {
83 idle_notifier_call_chain(IDLE_START);
84 ledtrig_cpu(CPU_LED_IDLE_START);
85 #ifdef CONFIG_PL310_ERRATA_769419
86 wmb();
87 #endif
88 }
89
arch_cpu_idle_exit(void)90 void arch_cpu_idle_exit(void)
91 {
92 ledtrig_cpu(CPU_LED_IDLE_END);
93 idle_notifier_call_chain(IDLE_END);
94 }
95
96 /*
97 * dump a block of kernel memory from around the given address
98 */
show_data(unsigned long addr,int nbytes,const char * name)99 static void show_data(unsigned long addr, int nbytes, const char *name)
100 {
101 int i, j;
102 int nlines;
103 u32 *p;
104
105 /*
106 * don't attempt to dump non-kernel addresses or
107 * values that are probably just small negative numbers
108 */
109 if (addr < PAGE_OFFSET || addr > -256UL)
110 return;
111
112 printk("\n%s: %#lx:\n", name, addr);
113
114 /*
115 * round address down to a 32 bit boundary
116 * and always dump a multiple of 32 bytes
117 */
118 p = (u32 *)(addr & ~(sizeof(u32) - 1));
119 nbytes += (addr & (sizeof(u32) - 1));
120 nlines = (nbytes + 31) / 32;
121
122
123 for (i = 0; i < nlines; i++) {
124 /*
125 * just display low 16 bits of address to keep
126 * each line of the dump < 80 characters
127 */
128 printk("%04lx ", (unsigned long)p & 0xffff);
129 for (j = 0; j < 8; j++) {
130 u32 data;
131 if (probe_kernel_address(p, data)) {
132 pr_cont(" ********");
133 } else {
134 pr_cont(" %08x", data);
135 }
136 ++p;
137 }
138 pr_cont("\n");
139 }
140 }
141
show_extra_register_data(struct pt_regs * regs,int nbytes)142 static void show_extra_register_data(struct pt_regs *regs, int nbytes)
143 {
144 mm_segment_t fs;
145
146 fs = get_fs();
147 set_fs(KERNEL_DS);
148 show_data(regs->ARM_pc - nbytes, nbytes * 2, "PC");
149 show_data(regs->ARM_lr - nbytes, nbytes * 2, "LR");
150 show_data(regs->ARM_sp - nbytes, nbytes * 2, "SP");
151 show_data(regs->ARM_ip - nbytes, nbytes * 2, "IP");
152 show_data(regs->ARM_fp - nbytes, nbytes * 2, "FP");
153 show_data(regs->ARM_r0 - nbytes, nbytes * 2, "R0");
154 show_data(regs->ARM_r1 - nbytes, nbytes * 2, "R1");
155 show_data(regs->ARM_r2 - nbytes, nbytes * 2, "R2");
156 show_data(regs->ARM_r3 - nbytes, nbytes * 2, "R3");
157 show_data(regs->ARM_r4 - nbytes, nbytes * 2, "R4");
158 show_data(regs->ARM_r5 - nbytes, nbytes * 2, "R5");
159 show_data(regs->ARM_r6 - nbytes, nbytes * 2, "R6");
160 show_data(regs->ARM_r7 - nbytes, nbytes * 2, "R7");
161 show_data(regs->ARM_r8 - nbytes, nbytes * 2, "R8");
162 show_data(regs->ARM_r9 - nbytes, nbytes * 2, "R9");
163 show_data(regs->ARM_r10 - nbytes, nbytes * 2, "R10");
164 set_fs(fs);
165 }
166
__show_regs(struct pt_regs * regs)167 void __show_regs(struct pt_regs *regs)
168 {
169 unsigned long flags;
170 char buf[64];
171 #ifndef CONFIG_CPU_V7M
172 unsigned int domain, fs;
173 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
174 /*
175 * Get the domain register for the parent context. In user
176 * mode, we don't save the DACR, so lets use what it should
177 * be. For other modes, we place it after the pt_regs struct.
178 */
179 if (user_mode(regs)) {
180 domain = DACR_UACCESS_ENABLE;
181 fs = get_fs();
182 } else {
183 domain = to_svc_pt_regs(regs)->dacr;
184 fs = to_svc_pt_regs(regs)->addr_limit;
185 }
186 #else
187 domain = get_domain();
188 fs = get_fs();
189 #endif
190 #endif
191
192 show_regs_print_info(KERN_DEFAULT);
193
194 print_symbol("PC is at %s\n", instruction_pointer(regs));
195 print_symbol("LR is at %s\n", regs->ARM_lr);
196 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
197 "sp : %08lx ip : %08lx fp : %08lx\n",
198 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
199 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
200 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
201 regs->ARM_r10, regs->ARM_r9,
202 regs->ARM_r8);
203 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
204 regs->ARM_r7, regs->ARM_r6,
205 regs->ARM_r5, regs->ARM_r4);
206 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
207 regs->ARM_r3, regs->ARM_r2,
208 regs->ARM_r1, regs->ARM_r0);
209
210 flags = regs->ARM_cpsr;
211 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
212 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
213 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
214 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
215 buf[4] = '\0';
216
217 #ifndef CONFIG_CPU_V7M
218 {
219 const char *segment;
220
221 if ((domain & domain_mask(DOMAIN_USER)) ==
222 domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
223 segment = "none";
224 else if (fs == get_ds())
225 segment = "kernel";
226 else
227 segment = "user";
228
229 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
230 buf, interrupts_enabled(regs) ? "n" : "ff",
231 fast_interrupts_enabled(regs) ? "n" : "ff",
232 processor_modes[processor_mode(regs)],
233 isa_modes[isa_mode(regs)], segment);
234 }
235 #else
236 printk("xPSR: %08lx\n", regs->ARM_cpsr);
237 #endif
238
239 #ifdef CONFIG_CPU_CP15
240 {
241 unsigned int ctrl;
242
243 buf[0] = '\0';
244 #ifdef CONFIG_CPU_CP15_MMU
245 {
246 unsigned int transbase;
247 asm("mrc p15, 0, %0, c2, c0\n\t"
248 : "=r" (transbase));
249 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
250 transbase, domain);
251 }
252 #endif
253 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
254
255 printk("Control: %08x%s\n", ctrl, buf);
256 }
257 #endif
258
259 show_extra_register_data(regs, 128);
260 }
261
show_regs(struct pt_regs * regs)262 void show_regs(struct pt_regs * regs)
263 {
264 __show_regs(regs);
265 dump_stack();
266 }
267
268 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
269
270 EXPORT_SYMBOL_GPL(thread_notify_head);
271
272 /*
273 * Free current thread data structures etc..
274 */
exit_thread(struct task_struct * tsk)275 void exit_thread(struct task_struct *tsk)
276 {
277 thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk));
278 }
279
flush_thread(void)280 void flush_thread(void)
281 {
282 struct thread_info *thread = current_thread_info();
283 struct task_struct *tsk = current;
284
285 flush_ptrace_hw_breakpoint(tsk);
286
287 memset(thread->used_cp, 0, sizeof(thread->used_cp));
288 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
289 memset(&thread->fpstate, 0, sizeof(union fp_state));
290
291 flush_tls();
292
293 thread_notify(THREAD_NOTIFY_FLUSH, thread);
294 }
295
release_thread(struct task_struct * dead_task)296 void release_thread(struct task_struct *dead_task)
297 {
298 }
299
300 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
301
302 int
copy_thread(unsigned long clone_flags,unsigned long stack_start,unsigned long stk_sz,struct task_struct * p)303 copy_thread(unsigned long clone_flags, unsigned long stack_start,
304 unsigned long stk_sz, struct task_struct *p)
305 {
306 struct thread_info *thread = task_thread_info(p);
307 struct pt_regs *childregs = task_pt_regs(p);
308
309 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
310
311 #ifdef CONFIG_CPU_USE_DOMAINS
312 /*
313 * Copy the initial value of the domain access control register
314 * from the current thread: thread->addr_limit will have been
315 * copied from the current thread via setup_thread_stack() in
316 * kernel/fork.c
317 */
318 thread->cpu_domain = get_domain();
319 #endif
320
321 if (likely(!(p->flags & PF_KTHREAD))) {
322 *childregs = *current_pt_regs();
323 childregs->ARM_r0 = 0;
324 if (stack_start)
325 childregs->ARM_sp = stack_start;
326 } else {
327 memset(childregs, 0, sizeof(struct pt_regs));
328 thread->cpu_context.r4 = stk_sz;
329 thread->cpu_context.r5 = stack_start;
330 childregs->ARM_cpsr = SVC_MODE;
331 }
332 thread->cpu_context.pc = (unsigned long)ret_from_fork;
333 thread->cpu_context.sp = (unsigned long)childregs;
334
335 clear_ptrace_hw_breakpoint(p);
336
337 if (clone_flags & CLONE_SETTLS)
338 thread->tp_value[0] = childregs->ARM_r3;
339 thread->tp_value[1] = get_tpuser();
340
341 thread_notify(THREAD_NOTIFY_COPY, thread);
342
343 return 0;
344 }
345
346 /*
347 * Fill in the task's elfregs structure for a core dump.
348 */
dump_task_regs(struct task_struct * t,elf_gregset_t * elfregs)349 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
350 {
351 elf_core_copy_regs(elfregs, task_pt_regs(t));
352 return 1;
353 }
354
355 /*
356 * fill in the fpe structure for a core dump...
357 */
dump_fpu(struct pt_regs * regs,struct user_fp * fp)358 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
359 {
360 struct thread_info *thread = current_thread_info();
361 int used_math = thread->used_cp[1] | thread->used_cp[2];
362
363 if (used_math)
364 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
365
366 return used_math != 0;
367 }
368 EXPORT_SYMBOL(dump_fpu);
369
get_wchan(struct task_struct * p)370 unsigned long get_wchan(struct task_struct *p)
371 {
372 struct stackframe frame;
373 unsigned long stack_page;
374 int count = 0;
375 if (!p || p == current || p->state == TASK_RUNNING)
376 return 0;
377
378 frame.fp = thread_saved_fp(p);
379 frame.sp = thread_saved_sp(p);
380 frame.lr = 0; /* recovered from the stack */
381 frame.pc = thread_saved_pc(p);
382 stack_page = (unsigned long)task_stack_page(p);
383 do {
384 if (frame.sp < stack_page ||
385 frame.sp >= stack_page + THREAD_SIZE ||
386 unwind_frame(&frame) < 0)
387 return 0;
388 if (!in_sched_functions(frame.pc))
389 return frame.pc;
390 } while (count ++ < 16);
391 return 0;
392 }
393
arch_randomize_brk(struct mm_struct * mm)394 unsigned long arch_randomize_brk(struct mm_struct *mm)
395 {
396 return randomize_page(mm->brk, 0x02000000);
397 }
398
399 #ifdef CONFIG_MMU
400 #ifdef CONFIG_KUSER_HELPERS
401 /*
402 * The vectors page is always readable from user space for the
403 * atomic helpers. Insert it into the gate_vma so that it is visible
404 * through ptrace and /proc/<pid>/mem.
405 */
406 static struct vm_area_struct gate_vma = {
407 .vm_start = 0xffff0000,
408 .vm_end = 0xffff0000 + PAGE_SIZE,
409 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
410 };
411
gate_vma_init(void)412 static int __init gate_vma_init(void)
413 {
414 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
415 return 0;
416 }
417 arch_initcall(gate_vma_init);
418
get_gate_vma(struct mm_struct * mm)419 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
420 {
421 return &gate_vma;
422 }
423
in_gate_area(struct mm_struct * mm,unsigned long addr)424 int in_gate_area(struct mm_struct *mm, unsigned long addr)
425 {
426 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
427 }
428
in_gate_area_no_mm(unsigned long addr)429 int in_gate_area_no_mm(unsigned long addr)
430 {
431 return in_gate_area(NULL, addr);
432 }
433 #define is_gate_vma(vma) ((vma) == &gate_vma)
434 #else
435 #define is_gate_vma(vma) 0
436 #endif
437
arch_vma_name(struct vm_area_struct * vma)438 const char *arch_vma_name(struct vm_area_struct *vma)
439 {
440 return is_gate_vma(vma) ? "[vectors]" : NULL;
441 }
442
443 /* If possible, provide a placement hint at a random offset from the
444 * stack for the sigpage and vdso pages.
445 */
sigpage_addr(const struct mm_struct * mm,unsigned int npages)446 static unsigned long sigpage_addr(const struct mm_struct *mm,
447 unsigned int npages)
448 {
449 unsigned long offset;
450 unsigned long first;
451 unsigned long last;
452 unsigned long addr;
453 unsigned int slots;
454
455 first = PAGE_ALIGN(mm->start_stack);
456
457 last = TASK_SIZE - (npages << PAGE_SHIFT);
458
459 /* No room after stack? */
460 if (first > last)
461 return 0;
462
463 /* Just enough room? */
464 if (first == last)
465 return first;
466
467 slots = ((last - first) >> PAGE_SHIFT) + 1;
468
469 offset = get_random_int() % slots;
470
471 addr = first + (offset << PAGE_SHIFT);
472
473 return addr;
474 }
475
476 static struct page *signal_page;
477 extern struct page *get_signal_page(void);
478
479 static const struct vm_special_mapping sigpage_mapping = {
480 .name = "[sigpage]",
481 .pages = &signal_page,
482 };
483
arch_setup_additional_pages(struct linux_binprm * bprm,int uses_interp)484 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
485 {
486 struct mm_struct *mm = current->mm;
487 struct vm_area_struct *vma;
488 unsigned long npages;
489 unsigned long addr;
490 unsigned long hint;
491 int ret = 0;
492
493 if (!signal_page)
494 signal_page = get_signal_page();
495 if (!signal_page)
496 return -ENOMEM;
497
498 npages = 1; /* for sigpage */
499 npages += vdso_total_pages;
500
501 if (down_write_killable(&mm->mmap_sem))
502 return -EINTR;
503 hint = sigpage_addr(mm, npages);
504 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
505 if (IS_ERR_VALUE(addr)) {
506 ret = addr;
507 goto up_fail;
508 }
509
510 vma = _install_special_mapping(mm, addr, PAGE_SIZE,
511 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
512 &sigpage_mapping);
513
514 if (IS_ERR(vma)) {
515 ret = PTR_ERR(vma);
516 goto up_fail;
517 }
518
519 mm->context.sigpage = addr;
520
521 /* Unlike the sigpage, failure to install the vdso is unlikely
522 * to be fatal to the process, so no error check needed
523 * here.
524 */
525 arm_install_vdso(mm, addr + PAGE_SIZE);
526
527 up_fail:
528 up_write(&mm->mmap_sem);
529 return ret;
530 }
531 #endif
532