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