diff options
Diffstat (limited to 'arch/arm/kernel/process.c')
| -rw-r--r-- | arch/arm/kernel/process.c | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c new file mode 100644 index 000000000..2647e48c5 --- /dev/null +++ b/arch/arm/kernel/process.c @@ -0,0 +1,448 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/arch/arm/kernel/process.c + * + * Copyright (C) 1996-2000 Russell King - Converted to ARM. + * Original Copyright (C) 1995 Linus Torvalds + */ +#include <stdarg.h> + +#include <linux/export.h> +#include <linux/sched.h> +#include <linux/sched/debug.h> +#include <linux/sched/task.h> +#include <linux/sched/task_stack.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/stddef.h> +#include <linux/unistd.h> +#include <linux/user.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/elfcore.h> +#include <linux/pm.h> +#include <linux/tick.h> +#include <linux/utsname.h> +#include <linux/uaccess.h> +#include <linux/random.h> +#include <linux/hw_breakpoint.h> +#include <linux/leds.h> + +#include <asm/processor.h> +#include <asm/thread_notify.h> +#include <asm/stacktrace.h> +#include <asm/system_misc.h> +#include <asm/mach/time.h> +#include <asm/tls.h> +#include <asm/vdso.h> + +#include "signal.h" + +#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + +static const char *processor_modes[] __maybe_unused = { + "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" , "MON_32" , "ABT_32" , + "UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32" +}; + +static const char *isa_modes[] __maybe_unused = { + "ARM" , "Thumb" , "Jazelle", "ThumbEE" +}; + +/* + * This is our default idle handler. + */ + +void (*arm_pm_idle)(void); + +/* + * Called from the core idle loop. + */ + +void arch_cpu_idle(void) +{ + if (arm_pm_idle) + arm_pm_idle(); + else + cpu_do_idle(); + raw_local_irq_enable(); +} + +void arch_cpu_idle_prepare(void) +{ + local_fiq_enable(); +} + +void arch_cpu_idle_enter(void) +{ + ledtrig_cpu(CPU_LED_IDLE_START); +#ifdef CONFIG_PL310_ERRATA_769419 + wmb(); +#endif +} + +void arch_cpu_idle_exit(void) +{ + ledtrig_cpu(CPU_LED_IDLE_END); +} + +void __show_regs(struct pt_regs *regs) +{ + unsigned long flags; + char buf[64]; +#ifndef CONFIG_CPU_V7M + unsigned int domain, fs; +#ifdef CONFIG_CPU_SW_DOMAIN_PAN + /* + * Get the domain register for the parent context. In user + * mode, we don't save the DACR, so lets use what it should + * be. For other modes, we place it after the pt_regs struct. + */ + if (user_mode(regs)) { + domain = DACR_UACCESS_ENABLE; + fs = get_fs(); + } else { + domain = to_svc_pt_regs(regs)->dacr; + fs = to_svc_pt_regs(regs)->addr_limit; + } +#else + domain = get_domain(); + fs = get_fs(); +#endif +#endif + + show_regs_print_info(KERN_DEFAULT); + + printk("PC is at %pS\n", (void *)instruction_pointer(regs)); + printk("LR is at %pS\n", (void *)regs->ARM_lr); + printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n", + regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr); + printk("sp : %08lx ip : %08lx fp : %08lx\n", + 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'; + +#ifndef CONFIG_CPU_V7M + { + const char *segment; + + if ((domain & domain_mask(DOMAIN_USER)) == + domain_val(DOMAIN_USER, DOMAIN_NOACCESS)) + segment = "none"; + else if (fs == KERNEL_DS) + segment = "kernel"; + else + segment = "user"; + + 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)], segment); + } +#else + printk("xPSR: %08lx\n", regs->ARM_cpsr); +#endif + +#ifdef CONFIG_CPU_CP15 + { + unsigned int ctrl; + + buf[0] = '\0'; +#ifdef CONFIG_CPU_CP15_MMU + { + unsigned int transbase; + asm("mrc p15, 0, %0, c2, c0\n\t" + : "=r" (transbase)); + snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", + transbase, domain); + } +#endif + asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); + + printk("Control: %08x%s\n", ctrl, buf); + } +#endif +} + +void show_regs(struct pt_regs * regs) +{ + __show_regs(regs); + dump_stack(); +} + +ATOMIC_NOTIFIER_HEAD(thread_notify_head); + +EXPORT_SYMBOL_GPL(thread_notify_head); + +/* + * Free current thread data structures etc.. + */ +void exit_thread(struct task_struct *tsk) +{ + thread_notify(THREAD_NOTIFY_EXIT, task_thread_info(tsk)); +} + +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)); + + flush_tls(); + + 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, unsigned long tls) +{ + struct thread_info *thread = task_thread_info(p); + struct pt_regs *childregs = task_pt_regs(p); + + memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); + +#ifdef CONFIG_CPU_USE_DOMAINS + /* + * Copy the initial value of the domain access control register + * from the current thread: thread->addr_limit will have been + * copied from the current thread via setup_thread_stack() in + * kernel/fork.c + */ + thread->cpu_domain = get_domain(); +#endif + + if (likely(!(p->flags & (PF_KTHREAD | PF_IO_WORKER)))) { + *childregs = *current_pt_regs(); + childregs->ARM_r0 = 0; + if (stack_start) + childregs->ARM_sp = stack_start; + } else { + memset(childregs, 0, sizeof(struct pt_regs)); + thread->cpu_context.r4 = stk_sz; + thread->cpu_context.r5 = stack_start; + childregs->ARM_cpsr = SVC_MODE; + } + thread->cpu_context.pc = (unsigned long)ret_from_fork; + thread->cpu_context.sp = (unsigned long)childregs; + + clear_ptrace_hw_breakpoint(p); + + if (clone_flags & CLONE_SETTLS) + thread->tp_value[0] = tls; + thread->tp_value[1] = get_tpuser(); + + thread_notify(THREAD_NOTIFY_COPY, thread); + +#ifdef CONFIG_STACKPROTECTOR_PER_TASK + thread->stack_canary = p->stack_canary; +#endif + + 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; +} + +unsigned long get_wchan(struct task_struct *p) +{ + struct stackframe frame; + unsigned long stack_page; + 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); + stack_page = (unsigned long)task_stack_page(p); + do { + if (frame.sp < stack_page || + frame.sp >= stack_page + THREAD_SIZE || + unwind_frame(&frame) < 0) + return 0; + if (!in_sched_functions(frame.pc)) + return frame.pc; + } while (count ++ < 16); + return 0; +} + +#ifdef CONFIG_MMU +#ifdef CONFIG_KUSER_HELPERS +/* + * The vectors page is always readable from user space for the + * atomic helpers. Insert it into the gate_vma so that it is visible + * through ptrace and /proc/<pid>/mem. + */ +static struct vm_area_struct gate_vma; + +static int __init gate_vma_init(void) +{ + vma_init(&gate_vma, NULL); + gate_vma.vm_page_prot = PAGE_READONLY_EXEC; + gate_vma.vm_start = 0xffff0000; + gate_vma.vm_end = 0xffff0000 + PAGE_SIZE; + gate_vma.vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC; + return 0; +} +arch_initcall(gate_vma_init); + +struct vm_area_struct *get_gate_vma(struct mm_struct *mm) +{ + return &gate_vma; +} + +int in_gate_area(struct mm_struct *mm, unsigned long addr) +{ + return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end); +} + +int in_gate_area_no_mm(unsigned long addr) +{ + return in_gate_area(NULL, addr); +} +#define is_gate_vma(vma) ((vma) == &gate_vma) +#else +#define is_gate_vma(vma) 0 +#endif + +const char *arch_vma_name(struct vm_area_struct *vma) +{ + return is_gate_vma(vma) ? "[vectors]" : NULL; +} + +/* If possible, provide a placement hint at a random offset from the + * stack for the sigpage and vdso pages. + */ +static unsigned long sigpage_addr(const struct mm_struct *mm, + unsigned int npages) +{ + unsigned long offset; + unsigned long first; + unsigned long last; + unsigned long addr; + unsigned int slots; + + first = PAGE_ALIGN(mm->start_stack); + + last = TASK_SIZE - (npages << PAGE_SHIFT); + + /* No room after stack? */ + if (first > last) + return 0; + + /* Just enough room? */ + if (first == last) + return first; + + slots = ((last - first) >> PAGE_SHIFT) + 1; + + offset = get_random_int() % slots; + + addr = first + (offset << PAGE_SHIFT); + + return addr; +} + +static struct page *signal_page; +extern struct page *get_signal_page(void); + +static int sigpage_mremap(const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + current->mm->context.sigpage = new_vma->vm_start; + return 0; +} + +static const struct vm_special_mapping sigpage_mapping = { + .name = "[sigpage]", + .pages = &signal_page, + .mremap = sigpage_mremap, +}; + +int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +{ + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + unsigned long npages; + unsigned long addr; + unsigned long hint; + int ret = 0; + + if (!signal_page) + signal_page = get_signal_page(); + if (!signal_page) + return -ENOMEM; + + npages = 1; /* for sigpage */ + npages += vdso_total_pages; + + if (mmap_write_lock_killable(mm)) + return -EINTR; + hint = sigpage_addr(mm, npages); + addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0); + if (IS_ERR_VALUE(addr)) { + ret = addr; + goto up_fail; + } + + vma = _install_special_mapping(mm, addr, PAGE_SIZE, + VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, + &sigpage_mapping); + + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + goto up_fail; + } + + mm->context.sigpage = addr; + + /* Unlike the sigpage, failure to install the vdso is unlikely + * to be fatal to the process, so no error check needed + * here. + */ + arm_install_vdso(mm, addr + PAGE_SIZE); + + up_fail: + mmap_write_unlock(mm); + return ret; +} +#endif |