v4.19.13 snapshot.
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
new file mode 100644
index 0000000..82ab015
--- /dev/null
+++ b/arch/arm/kernel/process.c
@@ -0,0 +1,466 @@
+/*
+ * 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 <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>
+
+#ifdef CONFIG_STACKPROTECTOR
+#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();
+ 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 == get_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)
+{
+ 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))) {
+ *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] = childregs->ARM_r3;
+ thread->tp_value[1] = get_tpuser();
+
+ 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);
+
+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;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+ return randomize_page(mm->brk, 0x02000000);
+}
+
+#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 (down_write_killable(&mm->mmap_sem))
+ 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:
+ up_write(&mm->mmap_sem);
+ return ret;
+}
+#endif