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 /* 230 * Copy the initial value of the domain access control register 231 * from the current thread: thread->addr_limit will have been 232 * copied from the current thread via setup_thread_stack() in 233 * kernel/fork.c 234 */ 235 thread->cpu_domain = get_domain(); 236 237 if (likely(!(p->flags & PF_KTHREAD))) { 238 *childregs = *current_pt_regs(); 239 childregs->ARM_r0 = 0; 240 if (stack_start) 241 childregs->ARM_sp = stack_start; 242 } else { 243 memset(childregs, 0, sizeof(struct pt_regs)); 244 thread->cpu_context.r4 = stk_sz; 245 thread->cpu_context.r5 = stack_start; 246 childregs->ARM_cpsr = SVC_MODE; 247 } 248 thread->cpu_context.pc = (unsigned long)ret_from_fork; 249 thread->cpu_context.sp = (unsigned long)childregs; 250 251 clear_ptrace_hw_breakpoint(p); 252 253 if (clone_flags & CLONE_SETTLS) 254 thread->tp_value[0] = childregs->ARM_r3; 255 thread->tp_value[1] = get_tpuser(); 256 257 thread_notify(THREAD_NOTIFY_COPY, thread); 258 259 return 0; 260 } 261 262 /* 263 * Fill in the task's elfregs structure for a core dump. 264 */ 265 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs) 266 { 267 elf_core_copy_regs(elfregs, task_pt_regs(t)); 268 return 1; 269 } 270 271 /* 272 * fill in the fpe structure for a core dump... 273 */ 274 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 275 { 276 struct thread_info *thread = current_thread_info(); 277 int used_math = thread->used_cp[1] | thread->used_cp[2]; 278 279 if (used_math) 280 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 281 282 return used_math != 0; 283 } 284 EXPORT_SYMBOL(dump_fpu); 285 286 unsigned long get_wchan(struct task_struct *p) 287 { 288 struct stackframe frame; 289 unsigned long stack_page; 290 int count = 0; 291 if (!p || p == current || p->state == TASK_RUNNING) 292 return 0; 293 294 frame.fp = thread_saved_fp(p); 295 frame.sp = thread_saved_sp(p); 296 frame.lr = 0; /* recovered from the stack */ 297 frame.pc = thread_saved_pc(p); 298 stack_page = (unsigned long)task_stack_page(p); 299 do { 300 if (frame.sp < stack_page || 301 frame.sp >= stack_page + THREAD_SIZE || 302 unwind_frame(&frame) < 0) 303 return 0; 304 if (!in_sched_functions(frame.pc)) 305 return frame.pc; 306 } while (count ++ < 16); 307 return 0; 308 } 309 310 unsigned long arch_randomize_brk(struct mm_struct *mm) 311 { 312 unsigned long range_end = mm->brk + 0x02000000; 313 return randomize_range(mm->brk, range_end, 0) ? : mm->brk; 314 } 315 316 #ifdef CONFIG_MMU 317 #ifdef CONFIG_KUSER_HELPERS 318 /* 319 * The vectors page is always readable from user space for the 320 * atomic helpers. Insert it into the gate_vma so that it is visible 321 * through ptrace and /proc/<pid>/mem. 322 */ 323 static struct vm_area_struct gate_vma = { 324 .vm_start = 0xffff0000, 325 .vm_end = 0xffff0000 + PAGE_SIZE, 326 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC, 327 }; 328 329 static int __init gate_vma_init(void) 330 { 331 gate_vma.vm_page_prot = PAGE_READONLY_EXEC; 332 return 0; 333 } 334 arch_initcall(gate_vma_init); 335 336 struct vm_area_struct *get_gate_vma(struct mm_struct *mm) 337 { 338 return &gate_vma; 339 } 340 341 int in_gate_area(struct mm_struct *mm, unsigned long addr) 342 { 343 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end); 344 } 345 346 int in_gate_area_no_mm(unsigned long addr) 347 { 348 return in_gate_area(NULL, addr); 349 } 350 #define is_gate_vma(vma) ((vma) == &gate_vma) 351 #else 352 #define is_gate_vma(vma) 0 353 #endif 354 355 const char *arch_vma_name(struct vm_area_struct *vma) 356 { 357 return is_gate_vma(vma) ? "[vectors]" : NULL; 358 } 359 360 /* If possible, provide a placement hint at a random offset from the 361 * stack for the sigpage and vdso pages. 362 */ 363 static unsigned long sigpage_addr(const struct mm_struct *mm, 364 unsigned int npages) 365 { 366 unsigned long offset; 367 unsigned long first; 368 unsigned long last; 369 unsigned long addr; 370 unsigned int slots; 371 372 first = PAGE_ALIGN(mm->start_stack); 373 374 last = TASK_SIZE - (npages << PAGE_SHIFT); 375 376 /* No room after stack? */ 377 if (first > last) 378 return 0; 379 380 /* Just enough room? */ 381 if (first == last) 382 return first; 383 384 slots = ((last - first) >> PAGE_SHIFT) + 1; 385 386 offset = get_random_int() % slots; 387 388 addr = first + (offset << PAGE_SHIFT); 389 390 return addr; 391 } 392 393 static struct page *signal_page; 394 extern struct page *get_signal_page(void); 395 396 static const struct vm_special_mapping sigpage_mapping = { 397 .name = "[sigpage]", 398 .pages = &signal_page, 399 }; 400 401 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 402 { 403 struct mm_struct *mm = current->mm; 404 struct vm_area_struct *vma; 405 unsigned long npages; 406 unsigned long addr; 407 unsigned long hint; 408 int ret = 0; 409 410 if (!signal_page) 411 signal_page = get_signal_page(); 412 if (!signal_page) 413 return -ENOMEM; 414 415 npages = 1; /* for sigpage */ 416 npages += vdso_total_pages; 417 418 down_write(&mm->mmap_sem); 419 hint = sigpage_addr(mm, npages); 420 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0); 421 if (IS_ERR_VALUE(addr)) { 422 ret = addr; 423 goto up_fail; 424 } 425 426 vma = _install_special_mapping(mm, addr, PAGE_SIZE, 427 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, 428 &sigpage_mapping); 429 430 if (IS_ERR(vma)) { 431 ret = PTR_ERR(vma); 432 goto up_fail; 433 } 434 435 mm->context.sigpage = addr; 436 437 /* Unlike the sigpage, failure to install the vdso is unlikely 438 * to be fatal to the process, so no error check needed 439 * here. 440 */ 441 arm_install_vdso(mm, addr + PAGE_SIZE); 442 443 up_fail: 444 up_write(&mm->mmap_sem); 445 return ret; 446 } 447 #endif 448