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(struct task_struct *tsk) 197 { 198 thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk)); 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 if (down_write_killable(&mm->mmap_sem)) 424 return -EINTR; 425 hint = sigpage_addr(mm, npages); 426 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0); 427 if (IS_ERR_VALUE(addr)) { 428 ret = addr; 429 goto up_fail; 430 } 431 432 vma = _install_special_mapping(mm, addr, PAGE_SIZE, 433 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, 434 &sigpage_mapping); 435 436 if (IS_ERR(vma)) { 437 ret = PTR_ERR(vma); 438 goto up_fail; 439 } 440 441 mm->context.sigpage = addr; 442 443 /* Unlike the sigpage, failure to install the vdso is unlikely 444 * to be fatal to the process, so no error check needed 445 * here. 446 */ 447 arm_install_vdso(mm, addr + PAGE_SIZE); 448 449 up_fail: 450 up_write(&mm->mmap_sem); 451 return ret; 452 } 453 #endif 454