| 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 | |
| 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 | |
| 76 | void arch_cpu_idle_prepare(void) |
| 77 | { |
| 78 | local_fiq_enable(); |
| 79 | } |
| 80 | |
| 81 | void arch_cpu_idle_enter(void) |
| 82 | { |
| 83 | ledtrig_cpu(CPU_LED_IDLE_START); |
| 84 | #ifdef CONFIG_PL310_ERRATA_769419 |
| 85 | wmb(); |
| 86 | #endif |
| 87 | } |
| 88 | |
| 89 | void arch_cpu_idle_exit(void) |
| 90 | { |
| 91 | ledtrig_cpu(CPU_LED_IDLE_END); |
| 92 | } |
| 93 | |
| 94 | void __show_regs(struct pt_regs *regs) |
| 95 | { |
| 96 | unsigned long flags; |
| 97 | char buf[64]; |
| 98 | #ifndef CONFIG_CPU_V7M |
| 99 | unsigned int domain; |
| 100 | #ifdef CONFIG_CPU_SW_DOMAIN_PAN |
| 101 | /* |
| 102 | * Get the domain register for the parent context. In user |
| 103 | * mode, we don't save the DACR, so lets use what it should |
| 104 | * be. For other modes, we place it after the pt_regs struct. |
| 105 | */ |
| 106 | if (user_mode(regs)) |
| 107 | domain = DACR_UACCESS_ENABLE; |
| 108 | else |
| 109 | domain = *(unsigned int *)(regs + 1); |
| 110 | #else |
| 111 | domain = get_domain(); |
| 112 | #endif |
| 113 | #endif |
| 114 | |
| 115 | show_regs_print_info(KERN_DEFAULT); |
| 116 | |
| 117 | print_symbol("PC is at %s\n", instruction_pointer(regs)); |
| 118 | print_symbol("LR is at %s\n", regs->ARM_lr); |
| 119 | printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" |
| 120 | "sp : %08lx ip : %08lx fp : %08lx\n", |
| 121 | regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, |
| 122 | regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); |
| 123 | printk("r10: %08lx r9 : %08lx r8 : %08lx\n", |
| 124 | regs->ARM_r10, regs->ARM_r9, |
| 125 | regs->ARM_r8); |
| 126 | printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", |
| 127 | regs->ARM_r7, regs->ARM_r6, |
| 128 | regs->ARM_r5, regs->ARM_r4); |
| 129 | printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", |
| 130 | regs->ARM_r3, regs->ARM_r2, |
| 131 | regs->ARM_r1, regs->ARM_r0); |
| 132 | |
| 133 | flags = regs->ARM_cpsr; |
| 134 | buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; |
| 135 | buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; |
| 136 | buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; |
| 137 | buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; |
| 138 | buf[4] = '\0'; |
| 139 | |
| 140 | #ifndef CONFIG_CPU_V7M |
| 141 | { |
| 142 | const char *segment; |
| 143 | |
| 144 | if ((domain & domain_mask(DOMAIN_USER)) == |
| 145 | domain_val(DOMAIN_USER, DOMAIN_NOACCESS)) |
| 146 | segment = "none"; |
| 147 | else if (get_fs() == get_ds()) |
| 148 | segment = "kernel"; |
| 149 | else |
| 150 | segment = "user"; |
| 151 | |
| 152 | printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", |
| 153 | buf, interrupts_enabled(regs) ? "n" : "ff", |
| 154 | fast_interrupts_enabled(regs) ? "n" : "ff", |
| 155 | processor_modes[processor_mode(regs)], |
| 156 | isa_modes[isa_mode(regs)], segment); |
| 157 | } |
| 158 | #else |
| 159 | printk("xPSR: %08lx\n", regs->ARM_cpsr); |
| 160 | #endif |
| 161 | |
| 162 | #ifdef CONFIG_CPU_CP15 |
| 163 | { |
| 164 | unsigned int ctrl; |
| 165 | |
| 166 | buf[0] = '\0'; |
| 167 | #ifdef CONFIG_CPU_CP15_MMU |
| 168 | { |
| 169 | unsigned int transbase; |
| 170 | asm("mrc p15, 0, %0, c2, c0\n\t" |
| 171 | : "=r" (transbase)); |
| 172 | snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", |
| 173 | transbase, domain); |
| 174 | } |
| 175 | #endif |
| 176 | asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); |
| 177 | |
| 178 | printk("Control: %08x%s\n", ctrl, buf); |
| 179 | } |
| 180 | #endif |
| 181 | } |
| 182 | |
| 183 | void show_regs(struct pt_regs * regs) |
| 184 | { |
| 185 | __show_regs(regs); |
| 186 | dump_stack(); |
| 187 | } |
| 188 | |
| 189 | ATOMIC_NOTIFIER_HEAD(thread_notify_head); |
| 190 | |
| 191 | EXPORT_SYMBOL_GPL(thread_notify_head); |
| 192 | |
| 193 | /* |
| 194 | * Free current thread data structures etc.. |
| 195 | */ |
| 196 | void exit_thread(void) |
| 197 | { |
| 198 | thread_notify(THREAD_NOTIFY_EXIT, current_thread_info()); |
| 199 | } |
| 200 | |
| 201 | void flush_thread(void) |
| 202 | { |
| 203 | struct thread_info *thread = current_thread_info(); |
| 204 | struct task_struct *tsk = current; |
| 205 | |
| 206 | flush_ptrace_hw_breakpoint(tsk); |
| 207 | |
| 208 | memset(thread->used_cp, 0, sizeof(thread->used_cp)); |
| 209 | memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); |
| 210 | memset(&thread->fpstate, 0, sizeof(union fp_state)); |
| 211 | |
| 212 | flush_tls(); |
| 213 | |
| 214 | thread_notify(THREAD_NOTIFY_FLUSH, thread); |
| 215 | } |
| 216 | |
| 217 | void release_thread(struct task_struct *dead_task) |
| 218 | { |
| 219 | } |
| 220 | |
| 221 | asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); |
| 222 | |
| 223 | int |
| 224 | copy_thread(unsigned long clone_flags, unsigned long stack_start, |
| 225 | unsigned long stk_sz, struct task_struct *p) |
| 226 | { |
| 227 | struct thread_info *thread = task_thread_info(p); |
| 228 | struct pt_regs *childregs = task_pt_regs(p); |
| 229 | |
| 230 | memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); |
| 231 | |
| 232 | #ifdef CONFIG_CPU_USE_DOMAINS |
| 233 | /* |
| 234 | * Copy the initial value of the domain access control register |
| 235 | * from the current thread: thread->addr_limit will have been |
| 236 | * copied from the current thread via setup_thread_stack() in |
| 237 | * kernel/fork.c |
| 238 | */ |
| 239 | thread->cpu_domain = get_domain(); |
| 240 | #endif |
| 241 | |
| 242 | if (likely(!(p->flags & PF_KTHREAD))) { |
| 243 | *childregs = *current_pt_regs(); |
| 244 | childregs->ARM_r0 = 0; |
| 245 | if (stack_start) |
| 246 | childregs->ARM_sp = stack_start; |
| 247 | } else { |
| 248 | memset(childregs, 0, sizeof(struct pt_regs)); |
| 249 | thread->cpu_context.r4 = stk_sz; |
| 250 | thread->cpu_context.r5 = stack_start; |
| 251 | childregs->ARM_cpsr = SVC_MODE; |
| 252 | } |
| 253 | thread->cpu_context.pc = (unsigned long)ret_from_fork; |
| 254 | thread->cpu_context.sp = (unsigned long)childregs; |
| 255 | |
| 256 | clear_ptrace_hw_breakpoint(p); |
| 257 | |
| 258 | if (clone_flags & CLONE_SETTLS) |
| 259 | thread->tp_value[0] = childregs->ARM_r3; |
| 260 | thread->tp_value[1] = get_tpuser(); |
| 261 | |
| 262 | thread_notify(THREAD_NOTIFY_COPY, thread); |
| 263 | |
| 264 | return 0; |
| 265 | } |
| 266 | |
| 267 | /* |
| 268 | * Fill in the task's elfregs structure for a core dump. |
| 269 | */ |
| 270 | int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs) |
| 271 | { |
| 272 | elf_core_copy_regs(elfregs, task_pt_regs(t)); |
| 273 | return 1; |
| 274 | } |
| 275 | |
| 276 | /* |
| 277 | * fill in the fpe structure for a core dump... |
| 278 | */ |
| 279 | int dump_fpu (struct pt_regs *regs, struct user_fp *fp) |
| 280 | { |
| 281 | struct thread_info *thread = current_thread_info(); |
| 282 | int used_math = thread->used_cp[1] | thread->used_cp[2]; |
| 283 | |
| 284 | if (used_math) |
| 285 | memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); |
| 286 | |
| 287 | return used_math != 0; |
| 288 | } |
| 289 | EXPORT_SYMBOL(dump_fpu); |
| 290 | |
| 291 | unsigned long get_wchan(struct task_struct *p) |
| 292 | { |
| 293 | struct stackframe frame; |
| 294 | unsigned long stack_page; |
| 295 | int count = 0; |
| 296 | if (!p || p == current || p->state == TASK_RUNNING) |
| 297 | return 0; |
| 298 | |
| 299 | frame.fp = thread_saved_fp(p); |
| 300 | frame.sp = thread_saved_sp(p); |
| 301 | frame.lr = 0; /* recovered from the stack */ |
| 302 | frame.pc = thread_saved_pc(p); |
| 303 | stack_page = (unsigned long)task_stack_page(p); |
| 304 | do { |
| 305 | if (frame.sp < stack_page || |
| 306 | frame.sp >= stack_page + THREAD_SIZE || |
| 307 | unwind_frame(&frame) < 0) |
| 308 | return 0; |
| 309 | if (!in_sched_functions(frame.pc)) |
| 310 | return frame.pc; |
| 311 | } while (count ++ < 16); |
| 312 | return 0; |
| 313 | } |
| 314 | |
| 315 | unsigned long arch_randomize_brk(struct mm_struct *mm) |
| 316 | { |
| 317 | unsigned long range_end = mm->brk + 0x02000000; |
| 318 | return randomize_range(mm->brk, range_end, 0) ? : mm->brk; |
| 319 | } |
| 320 | |
| 321 | #ifdef CONFIG_MMU |
| 322 | #ifdef CONFIG_KUSER_HELPERS |
| 323 | /* |
| 324 | * The vectors page is always readable from user space for the |
| 325 | * atomic helpers. Insert it into the gate_vma so that it is visible |
| 326 | * through ptrace and /proc/<pid>/mem. |
| 327 | */ |
| 328 | static struct vm_area_struct gate_vma = { |
| 329 | .vm_start = 0xffff0000, |
| 330 | .vm_end = 0xffff0000 + PAGE_SIZE, |
| 331 | .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC, |
| 332 | }; |
| 333 | |
| 334 | static int __init gate_vma_init(void) |
| 335 | { |
| 336 | gate_vma.vm_page_prot = PAGE_READONLY_EXEC; |
| 337 | return 0; |
| 338 | } |
| 339 | arch_initcall(gate_vma_init); |
| 340 | |
| 341 | struct vm_area_struct *get_gate_vma(struct mm_struct *mm) |
| 342 | { |
| 343 | return &gate_vma; |
| 344 | } |
| 345 | |
| 346 | int in_gate_area(struct mm_struct *mm, unsigned long addr) |
| 347 | { |
| 348 | return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end); |
| 349 | } |
| 350 | |
| 351 | int in_gate_area_no_mm(unsigned long addr) |
| 352 | { |
| 353 | return in_gate_area(NULL, addr); |
| 354 | } |
| 355 | #define is_gate_vma(vma) ((vma) == &gate_vma) |
| 356 | #else |
| 357 | #define is_gate_vma(vma) 0 |
| 358 | #endif |
| 359 | |
| 360 | const char *arch_vma_name(struct vm_area_struct *vma) |
| 361 | { |
| 362 | return is_gate_vma(vma) ? "[vectors]" : NULL; |
| 363 | } |
| 364 | |
| 365 | /* If possible, provide a placement hint at a random offset from the |
| 366 | * stack for the sigpage and vdso pages. |
| 367 | */ |
| 368 | static unsigned long sigpage_addr(const struct mm_struct *mm, |
| 369 | unsigned int npages) |
| 370 | { |
| 371 | unsigned long offset; |
| 372 | unsigned long first; |
| 373 | unsigned long last; |
| 374 | unsigned long addr; |
| 375 | unsigned int slots; |
| 376 | |
| 377 | first = PAGE_ALIGN(mm->start_stack); |
| 378 | |
| 379 | last = TASK_SIZE - (npages << PAGE_SHIFT); |
| 380 | |
| 381 | /* No room after stack? */ |
| 382 | if (first > last) |
| 383 | return 0; |
| 384 | |
| 385 | /* Just enough room? */ |
| 386 | if (first == last) |
| 387 | return first; |
| 388 | |
| 389 | slots = ((last - first) >> PAGE_SHIFT) + 1; |
| 390 | |
| 391 | offset = get_random_int() % slots; |
| 392 | |
| 393 | addr = first + (offset << PAGE_SHIFT); |
| 394 | |
| 395 | return addr; |
| 396 | } |
| 397 | |
| 398 | static struct page *signal_page; |
| 399 | extern struct page *get_signal_page(void); |
| 400 | |
| 401 | static const struct vm_special_mapping sigpage_mapping = { |
| 402 | .name = "[sigpage]", |
| 403 | .pages = &signal_page, |
| 404 | }; |
| 405 | |
| 406 | int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) |
| 407 | { |
| 408 | struct mm_struct *mm = current->mm; |
| 409 | struct vm_area_struct *vma; |
| 410 | unsigned long npages; |
| 411 | unsigned long addr; |
| 412 | unsigned long hint; |
| 413 | int ret = 0; |
| 414 | |
| 415 | if (!signal_page) |
| 416 | signal_page = get_signal_page(); |
| 417 | if (!signal_page) |
| 418 | return -ENOMEM; |
| 419 | |
| 420 | npages = 1; /* for sigpage */ |
| 421 | npages += vdso_total_pages; |
| 422 | |
| 423 | down_write(&mm->mmap_sem); |
| 424 | hint = sigpage_addr(mm, npages); |
| 425 | addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0); |
| 426 | if (IS_ERR_VALUE(addr)) { |
| 427 | ret = addr; |
| 428 | goto up_fail; |
| 429 | } |
| 430 | |
| 431 | vma = _install_special_mapping(mm, addr, PAGE_SIZE, |
| 432 | VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, |
| 433 | &sigpage_mapping); |
| 434 | |
| 435 | if (IS_ERR(vma)) { |
| 436 | ret = PTR_ERR(vma); |
| 437 | goto up_fail; |
| 438 | } |
| 439 | |
| 440 | mm->context.sigpage = addr; |
| 441 | |
| 442 | /* Unlike the sigpage, failure to install the vdso is unlikely |
| 443 | * to be fatal to the process, so no error check needed |
| 444 | * here. |
| 445 | */ |
| 446 | arm_install_vdso(mm, addr + PAGE_SIZE); |
| 447 | |
| 448 | up_fail: |
| 449 | up_write(&mm->mmap_sem); |
| 450 | return ret; |
| 451 | } |
| 452 | #endif |