| // 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_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(struct task_struct *p, const struct kernel_clone_args *args) |
| { |
| unsigned long clone_flags = args->flags; |
| unsigned long stack_start = args->stack; |
| unsigned long stk_sz = args->stack_size; |
| 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(!(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); |
| |
| 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; |
| 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 |