From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- arch/arm/kernel/process.c | 626 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 626 insertions(+) create mode 100644 arch/arm/kernel/process.c (limited to 'arch/arm/kernel/process.c') diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c new file mode 100644 index 00000000..300649c7 --- /dev/null +++ b/arch/arm/kernel/process.c @@ -0,0 +1,626 @@ +/* + * linux/arch/arm/kernel/process.c + * + * Copyright (C) 1996-2000 Russell King - Converted to ARM. + * Original Copyright (C) 1995 Linus Torvalds + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_CC_STACKPROTECTOR +#include +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + +static const char *processor_modes[] = { + "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" , + "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26", + "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" , + "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32" +}; + +static const char *isa_modes[] = { + "ARM" , "Thumb" , "Jazelle", "ThumbEE" +}; + +extern void setup_mm_for_reboot(char mode); + +static volatile int hlt_counter; + +#include + +#ifdef CONFIG_SMP +void arch_trigger_all_cpu_backtrace(void) +{ + smp_send_all_cpu_backtrace(); +} +#else +void arch_trigger_all_cpu_backtrace(void) +{ + dump_stack(); +} +#endif + +void disable_hlt(void) +{ + hlt_counter++; +} + +EXPORT_SYMBOL(disable_hlt); + +void enable_hlt(void) +{ + hlt_counter--; +} + +EXPORT_SYMBOL(enable_hlt); + +static int __init nohlt_setup(char *__unused) +{ + hlt_counter = 1; + return 1; +} + +static int __init hlt_setup(char *__unused) +{ + hlt_counter = 0; + return 1; +} + +__setup("nohlt", nohlt_setup); +__setup("hlt", hlt_setup); + +#ifdef CONFIG_ARM_FLUSH_CONSOLE_ON_RESTART +void arm_machine_flush_console(void) +{ + printk("\n"); + pr_emerg("Restarting %s\n", linux_banner); + if (console_trylock()) { + console_unlock(); + return; + } + + mdelay(50); + + local_irq_disable(); + if (!console_trylock()) + pr_emerg("arm_restart: Console was locked! Busting\n"); + else + pr_emerg("arm_restart: Console was locked!\n"); + console_unlock(); +} +#else +void arm_machine_flush_console(void) +{ +} +#endif + +void arm_machine_restart(char mode, const char *cmd) +{ + /* Flush the console to make sure all the relevant messages make it + * out to the console drivers */ + arm_machine_flush_console(); + + /* Disable interrupts first */ + local_irq_disable(); + local_fiq_disable(); + + /* + * Tell the mm system that we are going to reboot - + * we may need it to insert some 1:1 mappings so that + * soft boot works. + */ + setup_mm_for_reboot(mode); + + /* Clean and invalidate caches */ + flush_cache_all(); + + /* Turn off caching */ + cpu_proc_fin(); + + /* Push out any further dirty data, and ensure cache is empty */ + flush_cache_all(); + + /* + * Now call the architecture specific reboot code. + */ + arch_reset(mode, cmd); + + /* + * Whoops - the architecture was unable to reboot. + * Tell the user! + */ + mdelay(1000); + printk("Reboot failed -- System halted\n"); + while (1); +} + +/* + * Function pointers to optional machine specific functions + */ +void (*pm_power_off)(void); +EXPORT_SYMBOL(pm_power_off); + +void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart; +EXPORT_SYMBOL_GPL(arm_pm_restart); + +static void do_nothing(void *unused) +{ +} + +/* + * cpu_idle_wait - Used to ensure that all the CPUs discard old value of + * pm_idle and update to new pm_idle value. Required while changing pm_idle + * handler on SMP systems. + * + * Caller must have changed pm_idle to the new value before the call. Old + * pm_idle value will not be used by any CPU after the return of this function. + */ +void cpu_idle_wait(void) +{ + smp_mb(); + /* kick all the CPUs so that they exit out of pm_idle */ + smp_call_function(do_nothing, NULL, 1); +} +EXPORT_SYMBOL_GPL(cpu_idle_wait); + +/* + * This is our default idle handler. We need to disable + * interrupts here to ensure we don't miss a wakeup call. + */ +static void default_idle(void) +{ + if (!need_resched()) + arch_idle(); + local_irq_enable(); +} + +void (*pm_idle)(void) = default_idle; +EXPORT_SYMBOL(pm_idle); + +/* + * The idle thread, has rather strange semantics for calling pm_idle, + * but this is what x86 does and we need to do the same, so that + * things like cpuidle get called in the same way. The only difference + * is that we always respect 'hlt_counter' to prevent low power idle. + */ +void cpu_idle(void) +{ + local_fiq_enable(); + + /* endless idle loop with no priority at all */ + while (1) { + idle_notifier_call_chain(IDLE_START); + tick_nohz_stop_sched_tick(1); + while (!need_resched()) { +#ifdef CONFIG_HOTPLUG_CPU + if (cpu_is_offline(smp_processor_id())) + cpu_die(); +#endif + + local_irq_disable(); +#ifdef CONFIG_PL310_ERRATA_769419 + wmb(); +#endif + if (hlt_counter || tick_check_broadcast_pending()) { + local_irq_enable(); + cpu_relax(); + } else { + stop_critical_timings(); + pm_idle(); + start_critical_timings(); + /* + * This will eventually be removed - pm_idle + * functions should always return with IRQs + * enabled. + */ + WARN_ON(irqs_disabled()); + local_irq_enable(); + } + } + tick_nohz_restart_sched_tick(); + idle_notifier_call_chain(IDLE_END); + preempt_enable_no_resched(); + schedule(); + preempt_disable(); + } +} + +static char reboot_mode = 'h'; + +int __init reboot_setup(char *str) +{ + reboot_mode = str[0]; + return 1; +} + +__setup("reboot=", reboot_setup); + +void machine_shutdown(void) +{ +#ifdef CONFIG_SMP + smp_send_stop(); +#endif +} + +void machine_halt(void) +{ + machine_shutdown(); + while (1); +} + +void machine_power_off(void) +{ + machine_shutdown(); + if (pm_power_off) + pm_power_off(); +} + +void machine_restart(char *cmd) +{ + machine_shutdown(); + arm_pm_restart(reboot_mode, cmd); +} + +/* + * dump a block of kernel memory from around the given address + */ +static void show_data(unsigned long addr, int nbytes, const char *name) +{ + int i, j; + int nlines; + u32 *p; + + /* + * don't attempt to dump non-kernel addresses or + * values that are probably just small negative numbers + */ + if (addr < PAGE_OFFSET || addr > -256UL) + return; + + printk("\n%s: %#lx:\n", name, addr); + + /* + * round address down to a 32 bit boundary + * and always dump a multiple of 32 bytes + */ + p = (u32 *)(addr & ~(sizeof(u32) - 1)); + nbytes += (addr & (sizeof(u32) - 1)); + nlines = (nbytes + 31) / 32; + + + for (i = 0; i < nlines; i++) { + /* + * just display low 16 bits of address to keep + * each line of the dump < 80 characters + */ + printk("%04lx ", (unsigned long)p & 0xffff); + for (j = 0; j < 8; j++) { + u32 data; + if (probe_kernel_address(p, data)) { + printk(" ********"); + } else { + printk(" %08x", data); + } + ++p; + } + printk("\n"); + } +} + +static void show_extra_register_data(struct pt_regs *regs, int nbytes) +{ + mm_segment_t fs; + + fs = get_fs(); + set_fs(KERNEL_DS); + show_data(regs->ARM_pc - nbytes, nbytes * 2, "PC"); + show_data(regs->ARM_lr - nbytes, nbytes * 2, "LR"); + show_data(regs->ARM_sp - nbytes, nbytes * 2, "SP"); + show_data(regs->ARM_ip - nbytes, nbytes * 2, "IP"); + show_data(regs->ARM_fp - nbytes, nbytes * 2, "FP"); + show_data(regs->ARM_r0 - nbytes, nbytes * 2, "R0"); + show_data(regs->ARM_r1 - nbytes, nbytes * 2, "R1"); + show_data(regs->ARM_r2 - nbytes, nbytes * 2, "R2"); + show_data(regs->ARM_r3 - nbytes, nbytes * 2, "R3"); + show_data(regs->ARM_r4 - nbytes, nbytes * 2, "R4"); + show_data(regs->ARM_r5 - nbytes, nbytes * 2, "R5"); + show_data(regs->ARM_r6 - nbytes, nbytes * 2, "R6"); + show_data(regs->ARM_r7 - nbytes, nbytes * 2, "R7"); + show_data(regs->ARM_r8 - nbytes, nbytes * 2, "R8"); + show_data(regs->ARM_r9 - nbytes, nbytes * 2, "R9"); + show_data(regs->ARM_r10 - nbytes, nbytes * 2, "R10"); + set_fs(fs); +} + +void __show_regs(struct pt_regs *regs) +{ + unsigned long flags; + char buf[64]; + + printk("CPU: %d %s (%s %.*s)\n", + raw_smp_processor_id(), print_tainted(), + init_utsname()->release, + (int)strcspn(init_utsname()->version, " "), + init_utsname()->version); + print_symbol("PC is at %s\n", instruction_pointer(regs)); + print_symbol("LR is at %s\n", regs->ARM_lr); + printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" + "sp : %08lx ip : %08lx fp : %08lx\n", + regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, + regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); + printk("r10: %08lx r9 : %08lx r8 : %08lx\n", + regs->ARM_r10, regs->ARM_r9, + regs->ARM_r8); + printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", + regs->ARM_r7, regs->ARM_r6, + regs->ARM_r5, regs->ARM_r4); + printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", + regs->ARM_r3, regs->ARM_r2, + regs->ARM_r1, regs->ARM_r0); + + flags = regs->ARM_cpsr; + buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; + buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; + buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; + buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; + buf[4] = '\0'; + + printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", + buf, interrupts_enabled(regs) ? "n" : "ff", + fast_interrupts_enabled(regs) ? "n" : "ff", + processor_modes[processor_mode(regs)], + isa_modes[isa_mode(regs)], + get_fs() == get_ds() ? "kernel" : "user"); +#ifdef CONFIG_CPU_CP15 + { + unsigned int ctrl; + + buf[0] = '\0'; +#ifdef CONFIG_CPU_CP15_MMU + { + unsigned int transbase, dac; + asm("mrc p15, 0, %0, c2, c0\n\t" + "mrc p15, 0, %1, c3, c0\n" + : "=r" (transbase), "=r" (dac)); + snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", + transbase, dac); + } +#endif + asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); + + printk("Control: %08x%s\n", ctrl, buf); + } +#endif + + show_extra_register_data(regs, 128); +} + +void show_regs(struct pt_regs * regs) +{ + printk("\n"); + printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm); + __show_regs(regs); + __backtrace(); +} + +ATOMIC_NOTIFIER_HEAD(thread_notify_head); + +EXPORT_SYMBOL_GPL(thread_notify_head); + +/* + * Free current thread data structures etc.. + */ +void exit_thread(void) +{ + thread_notify(THREAD_NOTIFY_EXIT, current_thread_info()); +} + +void flush_thread(void) +{ + struct thread_info *thread = current_thread_info(); + struct task_struct *tsk = current; + + flush_ptrace_hw_breakpoint(tsk); + + memset(thread->used_cp, 0, sizeof(thread->used_cp)); + memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); + memset(&thread->fpstate, 0, sizeof(union fp_state)); + + thread_notify(THREAD_NOTIFY_FLUSH, thread); +} + +void release_thread(struct task_struct *dead_task) +{ +} + +asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); + +int +copy_thread(unsigned long clone_flags, unsigned long stack_start, + unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) +{ + struct thread_info *thread = task_thread_info(p); + struct pt_regs *childregs = task_pt_regs(p); + + *childregs = *regs; + childregs->ARM_r0 = 0; + childregs->ARM_sp = stack_start; + + memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); + thread->cpu_context.sp = (unsigned long)childregs; + thread->cpu_context.pc = (unsigned long)ret_from_fork; + + clear_ptrace_hw_breakpoint(p); + + if (clone_flags & CLONE_SETTLS) + thread->tp_value = regs->ARM_r3; + + thread_notify(THREAD_NOTIFY_COPY, thread); + + return 0; +} + +/* + * Fill in the task's elfregs structure for a core dump. + */ +int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs) +{ + elf_core_copy_regs(elfregs, task_pt_regs(t)); + return 1; +} + +/* + * fill in the fpe structure for a core dump... + */ +int dump_fpu (struct pt_regs *regs, struct user_fp *fp) +{ + struct thread_info *thread = current_thread_info(); + int used_math = thread->used_cp[1] | thread->used_cp[2]; + + if (used_math) + memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); + + return used_math != 0; +} +EXPORT_SYMBOL(dump_fpu); + +/* + * Shuffle the argument into the correct register before calling the + * thread function. r4 is the thread argument, r5 is the pointer to + * the thread function, and r6 points to the exit function. + */ +extern void kernel_thread_helper(void); +asm( ".pushsection .text\n" +" .align\n" +" .type kernel_thread_helper, #function\n" +"kernel_thread_helper:\n" +#ifdef CONFIG_TRACE_IRQFLAGS +" bl trace_hardirqs_on\n" +#endif +" msr cpsr_c, r7\n" +" mov r0, r4\n" +" mov lr, r6\n" +" mov pc, r5\n" +" .size kernel_thread_helper, . - kernel_thread_helper\n" +" .popsection"); + +#ifdef CONFIG_ARM_UNWIND +extern void kernel_thread_exit(long code); +asm( ".pushsection .text\n" +" .align\n" +" .type kernel_thread_exit, #function\n" +"kernel_thread_exit:\n" +" .fnstart\n" +" .cantunwind\n" +" bl do_exit\n" +" nop\n" +" .fnend\n" +" .size kernel_thread_exit, . - kernel_thread_exit\n" +" .popsection"); +#else +#define kernel_thread_exit do_exit +#endif + +/* + * Create a kernel thread. + */ +pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) +{ + struct pt_regs regs; + + memset(®s, 0, sizeof(regs)); + + regs.ARM_r4 = (unsigned long)arg; + regs.ARM_r5 = (unsigned long)fn; + regs.ARM_r6 = (unsigned long)kernel_thread_exit; + regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE; + regs.ARM_pc = (unsigned long)kernel_thread_helper; + regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT; + + return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); +} +EXPORT_SYMBOL(kernel_thread); + +unsigned long get_wchan(struct task_struct *p) +{ + struct stackframe frame; + int count = 0; + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + + frame.fp = thread_saved_fp(p); + frame.sp = thread_saved_sp(p); + frame.lr = 0; /* recovered from the stack */ + frame.pc = thread_saved_pc(p); + do { + int ret = unwind_frame(&frame); + if (ret < 0) + return 0; + if (!in_sched_functions(frame.pc)) + return frame.pc; + } while (count ++ < 16); + return 0; +} + +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + unsigned long range_end = mm->brk + 0x02000000; + return randomize_range(mm->brk, range_end, 0) ? : mm->brk; +} + +#ifdef CONFIG_MMU +/* + * The vectors page is always readable from user space for the + * atomic helpers and the signal restart code. Let's declare a mapping + * for it so it is visible through ptrace and /proc//mem. + */ + +int vectors_user_mapping(void) +{ + struct mm_struct *mm = current->mm; + return install_special_mapping(mm, 0xffff0000, PAGE_SIZE, + VM_READ | VM_EXEC | + VM_MAYREAD | VM_MAYEXEC | + VM_ALWAYSDUMP | VM_RESERVED, + NULL); +} + +const char *arch_vma_name(struct vm_area_struct *vma) +{ + return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL; +} +#endif -- cgit v1.2.3