2 * linux/arch/arm/kernel/process.c
4 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
5 * Original Copyright (C) 1995 Linus Torvalds
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.
13 #include <linux/export.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
17 #include <linux/stddef.h>
18 #include <linux/unistd.h>
19 #include <linux/user.h>
20 #include <linux/delay.h>
21 #include <linux/reboot.h>
22 #include <linux/interrupt.h>
23 #include <linux/kallsyms.h>
24 #include <linux/init.h>
25 #include <linux/cpu.h>
26 #include <linux/elfcore.h>
28 #include <linux/tick.h>
29 #include <linux/utsname.h>
30 #include <linux/uaccess.h>
31 #include <linux/random.h>
32 #include <linux/hw_breakpoint.h>
33 #include <linux/cpuidle.h>
34 #include <linux/leds.h>
35 #include <linux/console.h>
37 #include <asm/cacheflush.h>
38 #include <asm/idmap.h>
39 #include <asm/processor.h>
40 #include <asm/thread_notify.h>
41 #include <asm/stacktrace.h>
42 #include <asm/mach/time.h>
44 #ifdef CONFIG_CC_STACKPROTECTOR
45 #include <linux/stackprotector.h>
46 unsigned long __stack_chk_guard __read_mostly;
47 EXPORT_SYMBOL(__stack_chk_guard);
50 static const char *processor_modes[] = {
51 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
52 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
53 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
54 "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
57 static const char *isa_modes[] = {
58 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
62 void arch_trigger_all_cpu_backtrace(void)
64 smp_send_all_cpu_backtrace();
67 void arch_trigger_all_cpu_backtrace(void)
73 extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
74 typedef void (*phys_reset_t)(unsigned long);
76 #ifdef CONFIG_ARM_FLUSH_CONSOLE_ON_RESTART
77 void arm_machine_flush_console(void)
80 pr_emerg("Restarting %s\n", linux_banner);
81 if (console_trylock()) {
89 if (!console_trylock())
90 pr_emerg("arm_restart: Console was locked! Busting\n");
92 pr_emerg("arm_restart: Console was locked!\n");
96 void arm_machine_flush_console(void)
102 * A temporary stack to use for CPU reset. This is static so that we
103 * don't clobber it with the identity mapping. When running with this
104 * stack, any references to the current task *will not work* so you
105 * should really do as little as possible before jumping to your reset
108 static u64 soft_restart_stack[16];
110 static void __soft_restart(void *addr)
112 phys_reset_t phys_reset;
114 /* Take out a flat memory mapping. */
115 setup_mm_for_reboot();
117 /* Clean and invalidate caches */
120 /* Turn off caching */
123 /* Push out any further dirty data, and ensure cache is empty */
126 /* Switch to the identity mapping. */
127 phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
128 phys_reset((unsigned long)addr);
130 /* Should never get here. */
134 void soft_restart(unsigned long addr)
136 u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
138 /* Disable interrupts first */
142 /* Disable the L2 if we're the last man standing. */
143 if (num_online_cpus() == 1)
146 /* Change to the new stack and continue with the reset. */
147 call_with_stack(__soft_restart, (void *)addr, (void *)stack);
149 /* Should never get here. */
153 static void null_restart(char mode, const char *cmd)
158 * Function pointers to optional machine specific functions
160 void (*pm_power_off)(void);
161 EXPORT_SYMBOL(pm_power_off);
163 void (*arm_pm_restart)(char str, const char *cmd) = null_restart;
164 EXPORT_SYMBOL_GPL(arm_pm_restart);
167 * This is our default idle handler.
170 void (*arm_pm_idle)(void);
172 static void default_idle(void)
181 void arch_cpu_idle_prepare(void)
186 void arch_cpu_idle_enter(void)
188 idle_notifier_call_chain(IDLE_START);
189 ledtrig_cpu(CPU_LED_IDLE_START);
190 #ifdef CONFIG_PL310_ERRATA_769419
195 void arch_cpu_idle_exit(void)
197 ledtrig_cpu(CPU_LED_IDLE_END);
198 idle_notifier_call_chain(IDLE_END);
201 #ifdef CONFIG_HOTPLUG_CPU
202 void arch_cpu_idle_dead(void)
209 * Called from the core idle loop.
211 void arch_cpu_idle(void)
213 if (cpuidle_idle_call())
217 static char reboot_mode = 'h';
219 int __init reboot_setup(char *str)
221 reboot_mode = str[0];
225 __setup("reboot=", reboot_setup);
228 * Called by kexec, immediately prior to machine_kexec().
230 * This must completely disable all secondary CPUs; simply causing those CPUs
231 * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
232 * kexec'd kernel to use any and all RAM as it sees fit, without having to
233 * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
234 * functionality embodied in disable_nonboot_cpus() to achieve this.
236 void machine_shutdown(void)
240 * Disable preemption so we're guaranteed to
241 * run to power off or reboot and prevent
242 * the possibility of switching to another
243 * thread that might wind up blocking on
244 * one of the stopped CPUs.
248 disable_nonboot_cpus();
252 * Halting simply requires that the secondary CPUs stop performing any
253 * activity (executing tasks, handling interrupts). smp_send_stop()
256 void machine_halt(void)
266 * Power-off simply requires that the secondary CPUs stop performing any
267 * activity (executing tasks, handling interrupts). smp_send_stop()
268 * achieves this. When the system power is turned off, it will take all CPUs
271 void machine_power_off(void)
281 * Restart requires that the secondary CPUs stop performing any activity
282 * while the primary CPU resets the system. Systems with a single CPU can
283 * use soft_restart() as their machine descriptor's .restart hook, since that
284 * will cause the only available CPU to reset. Systems with multiple CPUs must
285 * provide a HW restart implementation, to ensure that all CPUs reset at once.
286 * This is required so that any code running after reset on the primary CPU
287 * doesn't have to co-ordinate with other CPUs to ensure they aren't still
288 * executing pre-reset code, and using RAM that the primary CPU's code wishes
289 * to use. Implementing such co-ordination would be essentially impossible.
291 void machine_restart(char *cmd)
296 /* Flush the console to make sure all the relevant messages make it
297 * out to the console drivers */
298 arm_machine_flush_console();
300 arm_pm_restart(reboot_mode, cmd);
302 /* Give a grace period for failure to restart of 1s */
305 /* Whoops - the platform was unable to reboot. Tell the user! */
306 printk("Reboot failed -- System halted\n");
312 * dump a block of kernel memory from around the given address
314 static void show_data(unsigned long addr, int nbytes, const char *name)
321 * don't attempt to dump non-kernel addresses or
322 * values that are probably just small negative numbers
324 if (addr < PAGE_OFFSET || addr > -256UL)
327 printk("\n%s: %#lx:\n", name, addr);
330 * round address down to a 32 bit boundary
331 * and always dump a multiple of 32 bytes
333 p = (u32 *)(addr & ~(sizeof(u32) - 1));
334 nbytes += (addr & (sizeof(u32) - 1));
335 nlines = (nbytes + 31) / 32;
338 for (i = 0; i < nlines; i++) {
340 * just display low 16 bits of address to keep
341 * each line of the dump < 80 characters
343 printk("%04lx ", (unsigned long)p & 0xffff);
344 for (j = 0; j < 8; j++) {
346 if (probe_kernel_address(p, data)) {
349 printk(" %08x", data);
357 static void show_extra_register_data(struct pt_regs *regs, int nbytes)
363 show_data(regs->ARM_pc - nbytes, nbytes * 2, "PC");
364 show_data(regs->ARM_lr - nbytes, nbytes * 2, "LR");
365 show_data(regs->ARM_sp - nbytes, nbytes * 2, "SP");
366 show_data(regs->ARM_ip - nbytes, nbytes * 2, "IP");
367 show_data(regs->ARM_fp - nbytes, nbytes * 2, "FP");
368 show_data(regs->ARM_r0 - nbytes, nbytes * 2, "R0");
369 show_data(regs->ARM_r1 - nbytes, nbytes * 2, "R1");
370 show_data(regs->ARM_r2 - nbytes, nbytes * 2, "R2");
371 show_data(regs->ARM_r3 - nbytes, nbytes * 2, "R3");
372 show_data(regs->ARM_r4 - nbytes, nbytes * 2, "R4");
373 show_data(regs->ARM_r5 - nbytes, nbytes * 2, "R5");
374 show_data(regs->ARM_r6 - nbytes, nbytes * 2, "R6");
375 show_data(regs->ARM_r7 - nbytes, nbytes * 2, "R7");
376 show_data(regs->ARM_r8 - nbytes, nbytes * 2, "R8");
377 show_data(regs->ARM_r9 - nbytes, nbytes * 2, "R9");
378 show_data(regs->ARM_r10 - nbytes, nbytes * 2, "R10");
382 void __show_regs(struct pt_regs *regs)
387 show_regs_print_info(KERN_DEFAULT);
389 print_symbol("PC is at %s\n", instruction_pointer(regs));
390 print_symbol("LR is at %s\n", regs->ARM_lr);
391 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
392 "sp : %08lx ip : %08lx fp : %08lx\n",
393 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
394 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
395 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
396 regs->ARM_r10, regs->ARM_r9,
398 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
399 regs->ARM_r7, regs->ARM_r6,
400 regs->ARM_r5, regs->ARM_r4);
401 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
402 regs->ARM_r3, regs->ARM_r2,
403 regs->ARM_r1, regs->ARM_r0);
405 flags = regs->ARM_cpsr;
406 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
407 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
408 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
409 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
412 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
413 buf, interrupts_enabled(regs) ? "n" : "ff",
414 fast_interrupts_enabled(regs) ? "n" : "ff",
415 processor_modes[processor_mode(regs)],
416 isa_modes[isa_mode(regs)],
417 get_fs() == get_ds() ? "kernel" : "user");
418 #ifdef CONFIG_CPU_CP15
423 #ifdef CONFIG_CPU_CP15_MMU
425 unsigned int transbase, dac;
426 asm("mrc p15, 0, %0, c2, c0\n\t"
427 "mrc p15, 0, %1, c3, c0\n"
428 : "=r" (transbase), "=r" (dac));
429 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
433 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
435 printk("Control: %08x%s\n", ctrl, buf);
439 show_extra_register_data(regs, 128);
442 void show_regs(struct pt_regs * regs)
449 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
451 EXPORT_SYMBOL_GPL(thread_notify_head);
454 * Free current thread data structures etc..
456 void exit_thread(void)
458 thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
461 void flush_thread(void)
463 struct thread_info *thread = current_thread_info();
464 struct task_struct *tsk = current;
466 flush_ptrace_hw_breakpoint(tsk);
468 memset(thread->used_cp, 0, sizeof(thread->used_cp));
469 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
470 memset(&thread->fpstate, 0, sizeof(union fp_state));
472 thread_notify(THREAD_NOTIFY_FLUSH, thread);
475 void release_thread(struct task_struct *dead_task)
479 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
482 copy_thread(unsigned long clone_flags, unsigned long stack_start,
483 unsigned long stk_sz, struct task_struct *p)
485 struct thread_info *thread = task_thread_info(p);
486 struct pt_regs *childregs = task_pt_regs(p);
488 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
490 if (likely(!(p->flags & PF_KTHREAD))) {
491 *childregs = *current_pt_regs();
492 childregs->ARM_r0 = 0;
494 childregs->ARM_sp = stack_start;
496 memset(childregs, 0, sizeof(struct pt_regs));
497 thread->cpu_context.r4 = stk_sz;
498 thread->cpu_context.r5 = stack_start;
499 childregs->ARM_cpsr = SVC_MODE;
501 thread->cpu_context.pc = (unsigned long)ret_from_fork;
502 thread->cpu_context.sp = (unsigned long)childregs;
504 clear_ptrace_hw_breakpoint(p);
506 if (clone_flags & CLONE_SETTLS)
507 thread->tp_value = childregs->ARM_r3;
509 thread_notify(THREAD_NOTIFY_COPY, thread);
515 * Fill in the task's elfregs structure for a core dump.
517 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
519 elf_core_copy_regs(elfregs, task_pt_regs(t));
524 * fill in the fpe structure for a core dump...
526 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
528 struct thread_info *thread = current_thread_info();
529 int used_math = thread->used_cp[1] | thread->used_cp[2];
532 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
534 return used_math != 0;
536 EXPORT_SYMBOL(dump_fpu);
538 unsigned long get_wchan(struct task_struct *p)
540 struct stackframe frame;
541 unsigned long stack_page;
543 if (!p || p == current || p->state == TASK_RUNNING)
546 frame.fp = thread_saved_fp(p);
547 frame.sp = thread_saved_sp(p);
548 frame.lr = 0; /* recovered from the stack */
549 frame.pc = thread_saved_pc(p);
550 stack_page = (unsigned long)task_stack_page(p);
552 if (frame.sp < stack_page ||
553 frame.sp >= stack_page + THREAD_SIZE ||
554 unwind_frame(&frame) < 0)
556 if (!in_sched_functions(frame.pc))
558 } while (count ++ < 16);
562 unsigned long arch_randomize_brk(struct mm_struct *mm)
564 unsigned long range_end = mm->brk + 0x02000000;
565 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
569 #ifdef CONFIG_KUSER_HELPERS
571 * The vectors page is always readable from user space for the
572 * atomic helpers. Insert it into the gate_vma so that it is visible
573 * through ptrace and /proc/<pid>/mem.
575 static struct vm_area_struct gate_vma = {
576 .vm_start = 0xffff0000,
577 .vm_end = 0xffff0000 + PAGE_SIZE,
578 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
581 static int __init gate_vma_init(void)
583 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
586 arch_initcall(gate_vma_init);
588 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
593 int in_gate_area(struct mm_struct *mm, unsigned long addr)
595 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
598 int in_gate_area_no_mm(unsigned long addr)
600 return in_gate_area(NULL, addr);
602 #define is_gate_vma(vma) ((vma) == &gate_vma)
604 #define is_gate_vma(vma) 0
607 const char *arch_vma_name(struct vm_area_struct *vma)
609 return is_gate_vma(vma) ? "[vectors]" :
610 (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
614 static struct page *signal_page;
615 extern struct page *get_signal_page(void);
617 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
619 struct mm_struct *mm = current->mm;
624 signal_page = get_signal_page();
628 down_write(&mm->mmap_sem);
629 addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
630 if (IS_ERR_VALUE(addr)) {
635 ret = install_special_mapping(mm, addr, PAGE_SIZE,
636 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
640 mm->context.sigpage = addr;
643 up_write(&mm->mmap_sem);