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 #ifdef CONFIG_HOTPLUG_CPU 95 void arch_cpu_idle_dead(void) 96 { 97 cpu_die(); 98 } 99 #endif 100 101 void __show_regs(struct pt_regs *regs) 102 { 103 unsigned long flags; 104 char buf[64]; 105 106 show_regs_print_info(KERN_DEFAULT); 107 108 print_symbol("PC is at %s\n", instruction_pointer(regs)); 109 print_symbol("LR is at %s\n", regs->ARM_lr); 110 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" 111 "sp : %08lx ip : %08lx fp : %08lx\n", 112 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, 113 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); 114 printk("r10: %08lx r9 : %08lx r8 : %08lx\n", 115 regs->ARM_r10, regs->ARM_r9, 116 regs->ARM_r8); 117 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", 118 regs->ARM_r7, regs->ARM_r6, 119 regs->ARM_r5, regs->ARM_r4); 120 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", 121 regs->ARM_r3, regs->ARM_r2, 122 regs->ARM_r1, regs->ARM_r0); 123 124 flags = regs->ARM_cpsr; 125 buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; 126 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; 127 buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; 128 buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; 129 buf[4] = '\0'; 130 131 #ifndef CONFIG_CPU_V7M 132 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", 133 buf, interrupts_enabled(regs) ? "n" : "ff", 134 fast_interrupts_enabled(regs) ? "n" : "ff", 135 processor_modes[processor_mode(regs)], 136 isa_modes[isa_mode(regs)], 137 get_fs() == get_ds() ? "kernel" : "user"); 138 #else 139 printk("xPSR: %08lx\n", regs->ARM_cpsr); 140 #endif 141 142 #ifdef CONFIG_CPU_CP15 143 { 144 unsigned int ctrl; 145 146 buf[0] = '\0'; 147 #ifdef CONFIG_CPU_CP15_MMU 148 { 149 unsigned int transbase, dac; 150 asm("mrc p15, 0, %0, c2, c0\n\t" 151 "mrc p15, 0, %1, c3, c0\n" 152 : "=r" (transbase), "=r" (dac)); 153 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", 154 transbase, dac); 155 } 156 #endif 157 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); 158 159 printk("Control: %08x%s\n", ctrl, buf); 160 } 161 #endif 162 } 163 164 void show_regs(struct pt_regs * regs) 165 { 166 __show_regs(regs); 167 dump_stack(); 168 } 169 170 ATOMIC_NOTIFIER_HEAD(thread_notify_head); 171 172 EXPORT_SYMBOL_GPL(thread_notify_head); 173 174 /* 175 * Free current thread data structures etc.. 176 */ 177 void exit_thread(void) 178 { 179 thread_notify(THREAD_NOTIFY_EXIT, current_thread_info()); 180 } 181 182 void flush_thread(void) 183 { 184 struct thread_info *thread = current_thread_info(); 185 struct task_struct *tsk = current; 186 187 flush_ptrace_hw_breakpoint(tsk); 188 189 memset(thread->used_cp, 0, sizeof(thread->used_cp)); 190 memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); 191 memset(&thread->fpstate, 0, sizeof(union fp_state)); 192 193 flush_tls(); 194 195 thread_notify(THREAD_NOTIFY_FLUSH, thread); 196 } 197 198 void release_thread(struct task_struct *dead_task) 199 { 200 } 201 202 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); 203 204 int 205 copy_thread(unsigned long clone_flags, unsigned long stack_start, 206 unsigned long stk_sz, struct task_struct *p) 207 { 208 struct thread_info *thread = task_thread_info(p); 209 struct pt_regs *childregs = task_pt_regs(p); 210 211 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); 212 213 if (likely(!(p->flags & PF_KTHREAD))) { 214 *childregs = *current_pt_regs(); 215 childregs->ARM_r0 = 0; 216 if (stack_start) 217 childregs->ARM_sp = stack_start; 218 } else { 219 memset(childregs, 0, sizeof(struct pt_regs)); 220 thread->cpu_context.r4 = stk_sz; 221 thread->cpu_context.r5 = stack_start; 222 childregs->ARM_cpsr = SVC_MODE; 223 } 224 thread->cpu_context.pc = (unsigned long)ret_from_fork; 225 thread->cpu_context.sp = (unsigned long)childregs; 226 227 clear_ptrace_hw_breakpoint(p); 228 229 if (clone_flags & CLONE_SETTLS) 230 thread->tp_value[0] = childregs->ARM_r3; 231 thread->tp_value[1] = get_tpuser(); 232 233 thread_notify(THREAD_NOTIFY_COPY, thread); 234 235 return 0; 236 } 237 238 /* 239 * Fill in the task's elfregs structure for a core dump. 240 */ 241 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs) 242 { 243 elf_core_copy_regs(elfregs, task_pt_regs(t)); 244 return 1; 245 } 246 247 /* 248 * fill in the fpe structure for a core dump... 249 */ 250 int dump_fpu (struct pt_regs *regs, struct user_fp *fp) 251 { 252 struct thread_info *thread = current_thread_info(); 253 int used_math = thread->used_cp[1] | thread->used_cp[2]; 254 255 if (used_math) 256 memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); 257 258 return used_math != 0; 259 } 260 EXPORT_SYMBOL(dump_fpu); 261 262 unsigned long get_wchan(struct task_struct *p) 263 { 264 struct stackframe frame; 265 unsigned long stack_page; 266 int count = 0; 267 if (!p || p == current || p->state == TASK_RUNNING) 268 return 0; 269 270 frame.fp = thread_saved_fp(p); 271 frame.sp = thread_saved_sp(p); 272 frame.lr = 0; /* recovered from the stack */ 273 frame.pc = thread_saved_pc(p); 274 stack_page = (unsigned long)task_stack_page(p); 275 do { 276 if (frame.sp < stack_page || 277 frame.sp >= stack_page + THREAD_SIZE || 278 unwind_frame(&frame) < 0) 279 return 0; 280 if (!in_sched_functions(frame.pc)) 281 return frame.pc; 282 } while (count ++ < 16); 283 return 0; 284 } 285 286 unsigned long arch_randomize_brk(struct mm_struct *mm) 287 { 288 unsigned long range_end = mm->brk + 0x02000000; 289 return randomize_range(mm->brk, range_end, 0) ? : mm->brk; 290 } 291 292 #ifdef CONFIG_MMU 293 #ifdef CONFIG_KUSER_HELPERS 294 /* 295 * The vectors page is always readable from user space for the 296 * atomic helpers. Insert it into the gate_vma so that it is visible 297 * through ptrace and /proc/<pid>/mem. 298 */ 299 static struct vm_area_struct gate_vma = { 300 .vm_start = 0xffff0000, 301 .vm_end = 0xffff0000 + PAGE_SIZE, 302 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC, 303 }; 304 305 static int __init gate_vma_init(void) 306 { 307 gate_vma.vm_page_prot = PAGE_READONLY_EXEC; 308 return 0; 309 } 310 arch_initcall(gate_vma_init); 311 312 struct vm_area_struct *get_gate_vma(struct mm_struct *mm) 313 { 314 return &gate_vma; 315 } 316 317 int in_gate_area(struct mm_struct *mm, unsigned long addr) 318 { 319 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end); 320 } 321 322 int in_gate_area_no_mm(unsigned long addr) 323 { 324 return in_gate_area(NULL, addr); 325 } 326 #define is_gate_vma(vma) ((vma) == &gate_vma) 327 #else 328 #define is_gate_vma(vma) 0 329 #endif 330 331 const char *arch_vma_name(struct vm_area_struct *vma) 332 { 333 return is_gate_vma(vma) ? "[vectors]" : NULL; 334 } 335 336 /* If possible, provide a placement hint at a random offset from the 337 * stack for the signal page. 338 */ 339 static unsigned long sigpage_addr(const struct mm_struct *mm, 340 unsigned int npages) 341 { 342 unsigned long offset; 343 unsigned long first; 344 unsigned long last; 345 unsigned long addr; 346 unsigned int slots; 347 348 first = PAGE_ALIGN(mm->start_stack); 349 350 last = TASK_SIZE - (npages << PAGE_SHIFT); 351 352 /* No room after stack? */ 353 if (first > last) 354 return 0; 355 356 /* Just enough room? */ 357 if (first == last) 358 return first; 359 360 slots = ((last - first) >> PAGE_SHIFT) + 1; 361 362 offset = get_random_int() % slots; 363 364 addr = first + (offset << PAGE_SHIFT); 365 366 return addr; 367 } 368 369 static struct page *signal_page; 370 extern struct page *get_signal_page(void); 371 372 static const struct vm_special_mapping sigpage_mapping = { 373 .name = "[sigpage]", 374 .pages = &signal_page, 375 }; 376 377 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 378 { 379 struct mm_struct *mm = current->mm; 380 struct vm_area_struct *vma; 381 unsigned long addr; 382 unsigned long hint; 383 int ret = 0; 384 385 if (!signal_page) 386 signal_page = get_signal_page(); 387 if (!signal_page) 388 return -ENOMEM; 389 390 down_write(&mm->mmap_sem); 391 hint = sigpage_addr(mm, 1); 392 addr = get_unmapped_area(NULL, hint, PAGE_SIZE, 0, 0); 393 if (IS_ERR_VALUE(addr)) { 394 ret = addr; 395 goto up_fail; 396 } 397 398 vma = _install_special_mapping(mm, addr, PAGE_SIZE, 399 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, 400 &sigpage_mapping); 401 402 if (IS_ERR(vma)) { 403 ret = PTR_ERR(vma); 404 goto up_fail; 405 } 406 407 mm->context.sigpage = addr; 408 409 up_fail: 410 up_write(&mm->mmap_sem); 411 return ret; 412 } 413 #endif 414