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- // 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 <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_CURRENT_POINTER_IN_TPIDRURO) || defined(CONFIG_SMP)
- DEFINE_PER_CPU(struct task_struct *, __entry_task);
- #endif
- #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
- #ifndef CONFIG_CURRENT_POINTER_IN_TPIDRURO
- asmlinkage struct task_struct *__current;
- EXPORT_SYMBOL(__current);
- #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_alloc_free(struct pt_regs *regs)
- {
- int i;
- /* check for r0 - r12 only */
- for (i = 0; i < 13; i++) {
- pr_alert("Register r%d information:", i);
- mem_dump_obj((void *)regs->uregs[i]);
- }
- }
- void __show_regs(struct pt_regs *regs)
- {
- unsigned long flags;
- char buf[64];
- #ifndef CONFIG_CPU_V7M
- unsigned int domain;
- #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;
- } else {
- domain = to_svc_pt_regs(regs)->dacr;
- }
- #else
- domain = get_domain();
- #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
- 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_backtrace(regs, NULL, KERN_DEFAULT);
- }
- 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);
- }
- asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
- int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
- {
- unsigned long clone_flags = args->flags;
- unsigned long stack_start = args->stack;
- unsigned long tls = args->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(!args->fn)) {
- *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 = (unsigned long)args->fn_arg;
- thread->cpu_context.r5 = (unsigned long)args->fn;
- 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);
- return 0;
- }
- unsigned long __get_wchan(struct task_struct *p)
- {
- struct stackframe frame;
- unsigned long stack_page;
- int count = 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;
- vm_flags_init(&gate_vma, 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 = prandom_u32_max(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
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