2 * linux/arch/arm/kernel/process.c
4 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
5 * Original Copyright (C) 1995 Linus Torvalds
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
13 #include <linux/export.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
17 #include <linux/stddef.h>
18 #include <linux/unistd.h>
19 #include <linux/user.h>
20 #include <linux/interrupt.h>
21 #include <linux/kallsyms.h>
22 #include <linux/init.h>
23 #include <linux/elfcore.h>
25 #include <linux/tick.h>
26 #include <linux/utsname.h>
27 #include <linux/uaccess.h>
28 #include <linux/random.h>
29 #include <linux/hw_breakpoint.h>
30 #include <linux/leds.h>
32 #include <asm/processor.h>
33 #include <asm/thread_notify.h>
34 #include <asm/stacktrace.h>
35 #include <asm/system_misc.h>
36 #include <asm/mach/time.h>
40 #ifdef CONFIG_CC_STACKPROTECTOR
41 #include <linux/stackprotector.h>
42 unsigned long __stack_chk_guard __read_mostly;
43 EXPORT_SYMBOL(__stack_chk_guard);
46 static const char *processor_modes[] __maybe_unused = {
47 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
48 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
49 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "MON_32" , "ABT_32" ,
50 "UK8_32" , "UK9_32" , "HYP_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
53 static const char *isa_modes[] __maybe_unused = {
54 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
58 * This is our default idle handler.
61 void (*arm_pm_idle)(void);
64 * Called from the core idle loop.
67 void arch_cpu_idle(void)
76 void arch_cpu_idle_prepare(void)
81 void arch_cpu_idle_enter(void)
83 ledtrig_cpu(CPU_LED_IDLE_START);
84 #ifdef CONFIG_PL310_ERRATA_769419
89 void arch_cpu_idle_exit(void)
91 ledtrig_cpu(CPU_LED_IDLE_END);
94 void __show_regs(struct pt_regs *regs)
98 #ifndef CONFIG_CPU_V7M
100 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
102 * Get the domain register for the parent context. In user
103 * mode, we don't save the DACR, so lets use what it should
104 * be. For other modes, we place it after the pt_regs struct.
107 domain = DACR_UACCESS_ENABLE;
109 domain = *(unsigned int *)(regs + 1);
111 domain = get_domain();
115 show_regs_print_info(KERN_DEFAULT);
117 print_symbol("PC is at %s\n", instruction_pointer(regs));
118 print_symbol("LR is at %s\n", regs->ARM_lr);
119 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
120 "sp : %08lx ip : %08lx fp : %08lx\n",
121 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
122 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
123 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
124 regs->ARM_r10, regs->ARM_r9,
126 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
127 regs->ARM_r7, regs->ARM_r6,
128 regs->ARM_r5, regs->ARM_r4);
129 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
130 regs->ARM_r3, regs->ARM_r2,
131 regs->ARM_r1, regs->ARM_r0);
133 flags = regs->ARM_cpsr;
134 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
135 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
136 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
137 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
140 #ifndef CONFIG_CPU_V7M
144 if ((domain & domain_mask(DOMAIN_USER)) ==
145 domain_val(DOMAIN_USER, DOMAIN_NOACCESS))
147 else if (get_fs() == get_ds())
152 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
153 buf, interrupts_enabled(regs) ? "n" : "ff",
154 fast_interrupts_enabled(regs) ? "n" : "ff",
155 processor_modes[processor_mode(regs)],
156 isa_modes[isa_mode(regs)], segment);
159 printk("xPSR: %08lx\n", regs->ARM_cpsr);
162 #ifdef CONFIG_CPU_CP15
167 #ifdef CONFIG_CPU_CP15_MMU
169 unsigned int transbase;
170 asm("mrc p15, 0, %0, c2, c0\n\t"
172 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
176 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
178 printk("Control: %08x%s\n", ctrl, buf);
183 void show_regs(struct pt_regs * regs)
189 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
191 EXPORT_SYMBOL_GPL(thread_notify_head);
194 * Free current thread data structures etc..
196 void exit_thread(void)
198 thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
201 void flush_thread(void)
203 struct thread_info *thread = current_thread_info();
204 struct task_struct *tsk = current;
206 flush_ptrace_hw_breakpoint(tsk);
208 memset(thread->used_cp, 0, sizeof(thread->used_cp));
209 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
210 memset(&thread->fpstate, 0, sizeof(union fp_state));
214 thread_notify(THREAD_NOTIFY_FLUSH, thread);
217 void release_thread(struct task_struct *dead_task)
221 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
224 copy_thread(unsigned long clone_flags, unsigned long stack_start,
225 unsigned long stk_sz, struct task_struct *p)
227 struct thread_info *thread = task_thread_info(p);
228 struct pt_regs *childregs = task_pt_regs(p);
230 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
232 #ifdef CONFIG_CPU_USE_DOMAINS
234 * Copy the initial value of the domain access control register
235 * from the current thread: thread->addr_limit will have been
236 * copied from the current thread via setup_thread_stack() in
239 thread->cpu_domain = get_domain();
242 if (likely(!(p->flags & PF_KTHREAD))) {
243 *childregs = *current_pt_regs();
244 childregs->ARM_r0 = 0;
246 childregs->ARM_sp = stack_start;
248 memset(childregs, 0, sizeof(struct pt_regs));
249 thread->cpu_context.r4 = stk_sz;
250 thread->cpu_context.r5 = stack_start;
251 childregs->ARM_cpsr = SVC_MODE;
253 thread->cpu_context.pc = (unsigned long)ret_from_fork;
254 thread->cpu_context.sp = (unsigned long)childregs;
256 clear_ptrace_hw_breakpoint(p);
258 if (clone_flags & CLONE_SETTLS)
259 thread->tp_value[0] = childregs->ARM_r3;
260 thread->tp_value[1] = get_tpuser();
262 thread_notify(THREAD_NOTIFY_COPY, thread);
268 * Fill in the task's elfregs structure for a core dump.
270 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
272 elf_core_copy_regs(elfregs, task_pt_regs(t));
277 * fill in the fpe structure for a core dump...
279 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
281 struct thread_info *thread = current_thread_info();
282 int used_math = thread->used_cp[1] | thread->used_cp[2];
285 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
287 return used_math != 0;
289 EXPORT_SYMBOL(dump_fpu);
291 unsigned long get_wchan(struct task_struct *p)
293 struct stackframe frame;
294 unsigned long stack_page;
296 if (!p || p == current || p->state == TASK_RUNNING)
299 frame.fp = thread_saved_fp(p);
300 frame.sp = thread_saved_sp(p);
301 frame.lr = 0; /* recovered from the stack */
302 frame.pc = thread_saved_pc(p);
303 stack_page = (unsigned long)task_stack_page(p);
305 if (frame.sp < stack_page ||
306 frame.sp >= stack_page + THREAD_SIZE ||
307 unwind_frame(&frame) < 0)
309 if (!in_sched_functions(frame.pc))
311 } while (count ++ < 16);
315 unsigned long arch_randomize_brk(struct mm_struct *mm)
317 unsigned long range_end = mm->brk + 0x02000000;
318 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
323 * CONFIG_SPLIT_PTLOCK_CPUS results in a page->ptl lock. If the lock is not
324 * initialized by pgtable_page_ctor() then a coredump of the vector page will
327 static int __init vectors_user_mapping_init_page(void)
330 unsigned long addr = 0xffff0000;
335 pgd = pgd_offset_k(addr);
336 pud = pud_offset(pgd, addr);
337 pmd = pmd_offset(pud, addr);
338 page = pmd_page(*(pmd));
340 pgtable_page_ctor(page);
344 late_initcall(vectors_user_mapping_init_page);
346 #ifdef CONFIG_KUSER_HELPERS
348 * The vectors page is always readable from user space for the
349 * atomic helpers. Insert it into the gate_vma so that it is visible
350 * through ptrace and /proc/<pid>/mem.
352 static struct vm_area_struct gate_vma = {
353 .vm_start = 0xffff0000,
354 .vm_end = 0xffff0000 + PAGE_SIZE,
355 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
358 static int __init gate_vma_init(void)
360 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
363 arch_initcall(gate_vma_init);
365 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
370 int in_gate_area(struct mm_struct *mm, unsigned long addr)
372 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
375 int in_gate_area_no_mm(unsigned long addr)
377 return in_gate_area(NULL, addr);
379 #define is_gate_vma(vma) ((vma) == &gate_vma)
381 #define is_gate_vma(vma) 0
384 const char *arch_vma_name(struct vm_area_struct *vma)
386 return is_gate_vma(vma) ? "[vectors]" : NULL;
389 /* If possible, provide a placement hint at a random offset from the
390 * stack for the sigpage and vdso pages.
392 static unsigned long sigpage_addr(const struct mm_struct *mm,
395 unsigned long offset;
401 first = PAGE_ALIGN(mm->start_stack);
403 last = TASK_SIZE - (npages << PAGE_SHIFT);
405 /* No room after stack? */
409 /* Just enough room? */
413 slots = ((last - first) >> PAGE_SHIFT) + 1;
415 offset = get_random_int() % slots;
417 addr = first + (offset << PAGE_SHIFT);
422 static struct page *signal_page;
423 extern struct page *get_signal_page(void);
425 static const struct vm_special_mapping sigpage_mapping = {
427 .pages = &signal_page,
430 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
432 struct mm_struct *mm = current->mm;
433 struct vm_area_struct *vma;
434 unsigned long npages;
440 signal_page = get_signal_page();
444 npages = 1; /* for sigpage */
445 npages += vdso_total_pages;
447 down_write(&mm->mmap_sem);
448 hint = sigpage_addr(mm, npages);
449 addr = get_unmapped_area(NULL, hint, npages << PAGE_SHIFT, 0, 0);
450 if (IS_ERR_VALUE(addr)) {
455 vma = _install_special_mapping(mm, addr, PAGE_SIZE,
456 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
464 mm->context.sigpage = addr;
466 /* Unlike the sigpage, failure to install the vdso is unlikely
467 * to be fatal to the process, so no error check needed
470 arm_install_vdso(mm, addr + PAGE_SIZE);
473 up_write(&mm->mmap_sem);