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, fs; 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 fs = get_fs(); 109 } else { 110 domain = to_svc_pt_regs(regs)->dacr; 111 fs = to_svc_pt_regs(regs)->addr_limit; 112 } 113 #else 114 domain = get_domain(); 115 fs = get_fs(); 116 #endif 117 #endif 118 119 show_regs_print_info(KERN_DEFAULT); 120 121 print_symbol("PC is at %s\n", instruction_pointer(regs)); 122 print_symbol("LR is at %s\n", regs->ARM_lr); 123 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" 124 "sp : %08lx ip : %08lx fp : %08lx\n", 125 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, 126 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); 127 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 128 regs->ARM_r10, regs->ARM_r9, 129 regs->ARM_r8); 130 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 131 regs->ARM_r7, regs->ARM_r6, 132 regs->ARM_r5, regs->ARM_r4); 133 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 134 regs->ARM_r3, regs->ARM_r2, 135 regs->ARM_r1, regs->ARM_r0); 136 137 flags = regs->ARM_cpsr; 138 buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; 139 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; 140 buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; 141 buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; 142 buf[4] = '\0'; 143 144 #ifndef CONFIG_CPU_V7M 145 { 146 const char *segment; 147 148 if ((domain & domain_mask(DOMAIN_USER)) == 149 domain_val(DOMAIN_USER, DOMAIN_NOACCESS)) 150 segment = "none"; 151 else if (fs == get_ds()) 152 segment = "kernel"; 153 else 154 segment = "user"; 155 156 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", 157 buf, interrupts_enabled(regs) ? "n" : "ff", 158 fast_interrupts_enabled(regs) ? "n" : "ff", 159 processor_modes[processor_mode(regs)], 160 isa_modes[isa_mode(regs)], segment); 161 } 162 #else 163 printk("xPSR: %08lx\n", regs->ARM_cpsr); 164 #endif 165 166 #ifdef CONFIG_CPU_CP15 167 { 168 unsigned int ctrl; 169 170 buf[0] = '\0'; 171 #ifdef CONFIG_CPU_CP15_MMU 172 { 173 unsigned int transbase; 174 asm("mrc p15, 0, %0, c2, c0\n\t" 175 : "=r" (transbase)); 176 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", 177 transbase, domain); 178 } 179 #endif 180 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); 181 182 printk("Control: %08x%s\n", ctrl, buf); 183 } 184 #endif 185 } 186 187 void show_regs(struct pt_regs * regs) 188 { 189 __show_regs(regs); 190 dump_stack(); 191 } 192 193 ATOMIC_NOTIFIER_HEAD(thread_notify_head); 194 195 EXPORT_SYMBOL_GPL(thread_notify_head); 196 197 /* 198 * Free current thread data structures etc.. 199 */ 200 void exit_thread(struct task_struct *tsk) 201 { 202 thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk)); 203 } 204 205 void flush_thread(void) 206 { 207 struct thread_info *thread = current_thread_info(); 208 struct task_struct *tsk = current; 209 210 flush_ptrace_hw_breakpoint(tsk); 211 212 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 213 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 214 memset(&thread->fpstate, 0, sizeof(union fp_state)); 215 216 flush_tls(); 217 218 thread_notify(THREAD_NOTIFY_FLUSH, thread); 219 } 220 221 void release_thread(struct task_struct *dead_task) 222 { 223 } 224 225 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 226 227 int 228 copy_thread(unsigned long clone_flags, unsigned long stack_start, 229 unsigned long stk_sz, struct task_struct *p) 230 { 231 struct thread_info *thread = task_thread_info(p); 232 struct pt_regs *childregs = task_pt_regs(p); 233 234 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 235 236 #ifdef CONFIG_CPU_USE_DOMAINS 237 /* 238 * Copy the initial value of the domain access control register 239 * from the current thread: thread->addr_limit will have been 240 * copied from the current thread via setup_thread_stack() in 241 * kernel/fork.c 242 */ 243 thread->cpu_domain = get_domain(); 244 #endif 245 246 if (likely(!(p->flags & PF_KTHREAD))) { 247 *childregs = *current_pt_regs(); 248 childregs->ARM_r0 = 0; 249 if (stack_start) 250 childregs->ARM_sp = stack_start; 251 } else { 252 memset(childregs, 0, sizeof(struct pt_regs)); 253 thread->cpu_context.r4 = stk_sz; 254 thread->cpu_context.r5 = stack_start; 255 childregs->ARM_cpsr = SVC_MODE; 256 } 257 thread->cpu_context.pc = (unsigned long)ret_from_fork; 258 thread->cpu_context.sp = (unsigned long)childregs; 259 260 clear_ptrace_hw_breakpoint(p); 261 262 if (clone_flags & CLONE_SETTLS) 263 thread->tp_value[0] = childregs->ARM_r3; 264 thread->tp_value[1] = get_tpuser(); 265 266 thread_notify(THREAD_NOTIFY_COPY, thread); 267 268 return 0; 269 } 270 271 /* 272 * Fill in the task's elfregs structure for a core dump. 273 */ 274 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs) 275 { 276 elf_core_copy_regs(elfregs, task_pt_regs(t)); 277 return 1; 278 } 279 280 /* 281 * fill in the fpe structure for a core dump... 282 */ 283 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 284 { 285 struct thread_info *thread = current_thread_info(); 286 int used_math = thread->used_cp[1] | thread->used_cp[2]; 287 288 if (used_math) 289 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 290 291 return used_math != 0; 292 } 293 EXPORT_SYMBOL(dump_fpu); 294 295 unsigned long get_wchan(struct task_struct *p) 296 { 297 struct stackframe frame; 298 unsigned long stack_page; 299 int count = 0; 300 if (!p || p == current || p->state == TASK_RUNNING) 301 return 0; 302 303 frame.fp = thread_saved_fp(p); 304 frame.sp = thread_saved_sp(p); 305 frame.lr = 0; /* recovered from the stack */ 306 frame.pc = thread_saved_pc(p); 307 stack_page = (unsigned long)task_stack_page(p); 308 do { 309 if (frame.sp < stack_page || 310 frame.sp >= stack_page + THREAD_SIZE || 311 unwind_frame(&frame) < 0) 312 return 0; 313 if (!in_sched_functions(frame.pc)) 314 return frame.pc; 315 } while (count ++ < 16); 316 return 0; 317 } 318 319 unsigned long arch_randomize_brk(struct mm_struct *mm) 320 { 321 return randomize_page(mm->brk, 0x02000000); 322 } 323 324 #ifdef CONFIG_MMU 325 #ifdef CONFIG_KUSER_HELPERS 326 /* 327 * The vectors page is always readable from user space for the 328 * atomic helpers. Insert it into the gate_vma so that it is visible 329 * through ptrace and /proc/<pid>/mem. 330 */ 331 static struct vm_area_struct gate_vma = { 332 .vm_start = 0xffff0000, 333 .vm_end = 0xffff0000 + PAGE_SIZE, 334 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC, 335 }; 336 337 static int __init gate_vma_init(void) 338 { 339 gate_vma.vm_page_prot = PAGE_READONLY_EXEC; 340 return 0; 341 } 342 arch_initcall(gate_vma_init); 343 344 struct vm_area_struct *get_gate_vma(struct mm_struct *mm) 345 { 346 return &gate_vma; 347 } 348 349 int in_gate_area(struct mm_struct *mm, unsigned long addr) 350 { 351 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end); 352 } 353 354 int in_gate_area_no_mm(unsigned long addr) 355 { 356 return in_gate_area(NULL, addr); 357 } 358 #define is_gate_vma(vma) ((vma) == &gate_vma) 359 #else 360 #define is_gate_vma(vma) 0 361 #endif 362 363 const char *arch_vma_name(struct vm_area_struct *vma) 364 { 365 return is_gate_vma(vma) ? "[vectors]" : NULL; 366 } 367 368 /* If possible, provide a placement hint at a random offset from the 369 * stack for the sigpage and vdso pages. 370 */ 371 static unsigned long sigpage_addr(const struct mm_struct *mm, 372 unsigned int npages) 373 { 374 unsigned long offset; 375 unsigned long first; 376 unsigned long last; 377 unsigned long addr; 378 unsigned int slots; 379 380 first = PAGE_ALIGN(mm->start_stack); 381 382 last = TASK_SIZE - (npages << PAGE_SHIFT); 383 384 /* No room after stack? */ 385 if (first > last) 386 return 0; 387 388 /* Just enough room? */ 389 if (first == last) 390 return first; 391 392 slots = ((last - first) >> PAGE_SHIFT) + 1; 393 394 offset = get_random_int() % slots; 395 396 addr = first + (offset << PAGE_SHIFT); 397 398 return addr; 399 } 400 401 static struct page *signal_page; 402 extern struct page *get_signal_page(void); 403 404 static const struct vm_special_mapping sigpage_mapping = { 405 .name = "[sigpage]", 406 .pages = &signal_page, 407 }; 408 409 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 410 { 411 struct mm_struct *mm = current->mm; 412 struct vm_area_struct *vma; 413 unsigned long npages; 414 unsigned long addr; 415 unsigned long hint; 416 int ret = 0; 417 418 if (!signal_page) 419 signal_page = get_signal_page(); 420 if (!signal_page) 421 return -ENOMEM; 422 423 npages = 1; /* for sigpage */ 424 npages += vdso_total_pages; 425 426 if (down_write_killable(&mm->mmap_sem)) 427 return -EINTR; 428 hint = sigpage_addr(mm, npages); 429 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0); 430 if (IS_ERR_VALUE(addr)) { 431 ret = addr; 432 goto up_fail; 433 } 434 435 vma = _install_special_mapping(mm, addr, PAGE_SIZE, 436 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, 437 &sigpage_mapping); 438 439 if (IS_ERR(vma)) { 440 ret = PTR_ERR(vma); 441 goto up_fail; 442 } 443 444 mm->context.sigpage = addr; 445 446 /* Unlike the sigpage, failure to install the vdso is unlikely 447 * to be fatal to the process, so no error check needed 448 * here. 449 */ 450 arm_install_vdso(mm, addr + PAGE_SIZE); 451 452 up_fail: 453 up_write(&mm->mmap_sem); 454 return ret; 455 } 456 #endif 457