[deliverable/linux.git] / arch / mips / kernel / process.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
 * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2004 Thiemo Seufer
 * Copyright (C) 2013  Imagination Technologies Ltd.
 */
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/tick.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/export.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/personality.h>
#include <linux/sys.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/kallsyms.h>
#include <linux/random.h>

#include <asm/asm.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/msa.h>
#include <asm/pgtable.h>
#include <asm/mipsregs.h>
#include <asm/processor.h>
#include <asm/reg.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/elf.h>
#include <asm/isadep.h>
#include <asm/inst.h>
#include <asm/stacktrace.h>
#include <asm/irq_regs.h>

#ifdef CONFIG_HOTPLUG_CPU
void arch_cpu_idle_dead(void)
{
	/* What the heck is this check doing ? */
	if (!cpu_isset(smp_processor_id(), cpu_callin_map))
		play_dead();
}
#endif

asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);

void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
{
	unsigned long status;

	/* New thread loses kernel privileges. */
	status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK);
	status |= KU_USER;
	regs->cp0_status = status;
	clear_used_math();
	clear_fpu_owner();
	init_dsp();
	clear_thread_flag(TIF_USEDMSA);
	clear_thread_flag(TIF_MSA_CTX_LIVE);
	disable_msa();
	regs->cp0_epc = pc;
	regs->regs[29] = sp;
}

void exit_thread(void)
{
}

void flush_thread(void)
{
}

int copy_thread(unsigned long clone_flags, unsigned long usp,
	unsigned long arg, struct task_struct *p)
{
	struct thread_info *ti = task_thread_info(p);
	struct pt_regs *childregs, *regs = current_pt_regs();
	unsigned long childksp;
	p->set_child_tid = p->clear_child_tid = NULL;

	childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;

	preempt_disable();

	if (is_msa_enabled())
		save_msa(p);
	else if (is_fpu_owner())
		save_fp(p);

	if (cpu_has_dsp)
		save_dsp(p);

	preempt_enable();

	/* set up new TSS. */
	childregs = (struct pt_regs *) childksp - 1;
	/*  Put the stack after the struct pt_regs.  */
	childksp = (unsigned long) childregs;
	p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
	if (unlikely(p->flags & PF_KTHREAD)) {
		unsigned long status = p->thread.cp0_status;
		memset(childregs, 0, sizeof(struct pt_regs));
		ti->addr_limit = KERNEL_DS;
		p->thread.reg16 = usp; /* fn */
		p->thread.reg17 = arg;
		p->thread.reg29 = childksp;
		p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
		status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
			 ((status & (ST0_KUC | ST0_IEC)) << 2);
#else
		status |= ST0_EXL;
#endif
		childregs->cp0_status = status;
		return 0;
	}
	*childregs = *regs;
	childregs->regs[7] = 0; /* Clear error flag */
	childregs->regs[2] = 0; /* Child gets zero as return value */
	if (usp)
		childregs->regs[29] = usp;
	ti->addr_limit = USER_DS;

	p->thread.reg29 = (unsigned long) childregs;
	p->thread.reg31 = (unsigned long) ret_from_fork;

	/*
	 * New tasks lose permission to use the fpu. This accelerates context
	 * switching for most programs since they don't use the fpu.
	 */
	childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);

	clear_tsk_thread_flag(p, TIF_USEDFPU);
	clear_tsk_thread_flag(p, TIF_USEDMSA);
	clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE);

#ifdef CONFIG_MIPS_MT_FPAFF
	clear_tsk_thread_flag(p, TIF_FPUBOUND);
#endif /* CONFIG_MIPS_MT_FPAFF */

	if (clone_flags & CLONE_SETTLS)
		ti->tp_value = regs->regs[7];

	return 0;
}

#ifdef CONFIG_CC_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif

struct mips_frame_info {
	void		*func;
	unsigned long	func_size;
	int		frame_size;
	int		pc_offset;
};

#define J_TARGET(pc,target)	\
		(((unsigned long)(pc) & 0xf0000000) | ((target) << 2))

static inline int is_ra_save_ins(union mips_instruction *ip)
{
#ifdef CONFIG_CPU_MICROMIPS
	union mips_instruction mmi;

	/*
	 * swsp ra,offset
	 * swm16 reglist,offset(sp)
	 * swm32 reglist,offset(sp)
	 * sw32 ra,offset(sp)
	 * jradiussp - NOT SUPPORTED
	 *
	 * microMIPS is way more fun...
	 */
	if (mm_insn_16bit(ip->halfword[0])) {
		mmi.word = (ip->halfword[0] << 16);
		return (mmi.mm16_r5_format.opcode == mm_swsp16_op &&
			mmi.mm16_r5_format.rt == 31) ||
		       (mmi.mm16_m_format.opcode == mm_pool16c_op &&
			mmi.mm16_m_format.func == mm_swm16_op);
	}
	else {
		mmi.halfword[0] = ip->halfword[1];
		mmi.halfword[1] = ip->halfword[0];
		return (mmi.mm_m_format.opcode == mm_pool32b_op &&
			mmi.mm_m_format.rd > 9 &&
			mmi.mm_m_format.base == 29 &&
			mmi.mm_m_format.func == mm_swm32_func) ||
		       (mmi.i_format.opcode == mm_sw32_op &&
			mmi.i_format.rs == 29 &&
			mmi.i_format.rt == 31);
	}
#else
	/* sw / sd $ra, offset($sp) */
	return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
		ip->i_format.rs == 29 &&
		ip->i_format.rt == 31;
#endif
}

static inline int is_jump_ins(union mips_instruction *ip)
{
#ifdef CONFIG_CPU_MICROMIPS
	/*
	 * jr16,jrc,jalr16,jalr16
	 * jal
	 * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb
	 * jraddiusp - NOT SUPPORTED
	 *
	 * microMIPS is kind of more fun...
	 */
	union mips_instruction mmi;

	mmi.word = (ip->halfword[0] << 16);

	if ((mmi.mm16_r5_format.opcode == mm_pool16c_op &&
	    (mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) ||
	    ip->j_format.opcode == mm_jal32_op)
		return 1;
	if (ip->r_format.opcode != mm_pool32a_op ||
			ip->r_format.func != mm_pool32axf_op)
		return 0;
	return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op;
#else
	if (ip->j_format.opcode == j_op)
		return 1;
	if (ip->j_format.opcode == jal_op)
		return 1;
	if (ip->r_format.opcode != spec_op)
		return 0;
	return ip->r_format.func == jalr_op || ip->r_format.func == jr_op;
#endif
}

static inline int is_sp_move_ins(union mips_instruction *ip)
{
#ifdef CONFIG_CPU_MICROMIPS
	/*
	 * addiusp -imm
	 * addius5 sp,-imm
	 * addiu32 sp,sp,-imm
	 * jradiussp - NOT SUPPORTED
	 *
	 * microMIPS is not more fun...
	 */
	if (mm_insn_16bit(ip->halfword[0])) {
		union mips_instruction mmi;

		mmi.word = (ip->halfword[0] << 16);
		return (mmi.mm16_r3_format.opcode == mm_pool16d_op &&
			mmi.mm16_r3_format.simmediate && mm_addiusp_func) ||
		       (mmi.mm16_r5_format.opcode == mm_pool16d_op &&
			mmi.mm16_r5_format.rt == 29);
	}
	return ip->mm_i_format.opcode == mm_addiu32_op &&
	       ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29;
#else
	/* addiu/daddiu sp,sp,-imm */
	if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
		return 0;
	if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op)
		return 1;
#endif
	return 0;
}

static int get_frame_info(struct mips_frame_info *info)
{
#ifdef CONFIG_CPU_MICROMIPS
	union mips_instruction *ip = (void *) (((char *) info->func) - 1);
#else
	union mips_instruction *ip = info->func;
#endif
	unsigned max_insns = info->func_size / sizeof(union mips_instruction);
	unsigned i;

	info->pc_offset = -1;
	info->frame_size = 0;

	if (!ip)
		goto err;

	if (max_insns == 0)
		max_insns = 128U;	/* unknown function size */
	max_insns = min(128U, max_insns);

	for (i = 0; i < max_insns; i++, ip++) {

		if (is_jump_ins(ip))
			break;
		if (!info->frame_size) {
			if (is_sp_move_ins(ip))
			{
#ifdef CONFIG_CPU_MICROMIPS
				if (mm_insn_16bit(ip->halfword[0]))
				{
					unsigned short tmp;

					if (ip->halfword[0] & mm_addiusp_func)
					{
						tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2);
						info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0));
					} else {
						tmp = (ip->halfword[0] >> 1);
						info->frame_size = -(signed short)(tmp & 0xf);
					}
					ip = (void *) &ip->halfword[1];
					ip--;
				} else
#endif
				info->frame_size = - ip->i_format.simmediate;
			}
			continue;
		}
		if (info->pc_offset == -1 && is_ra_save_ins(ip)) {
			info->pc_offset =
				ip->i_format.simmediate / sizeof(long);
			break;
		}
	}
	if (info->frame_size && info->pc_offset >= 0) /* nested */
		return 0;
	if (info->pc_offset < 0) /* leaf */
		return 1;
	/* prologue seems boggus... */
err:
	return -1;
}

static struct mips_frame_info schedule_mfi __read_mostly;

#ifdef CONFIG_KALLSYMS
static unsigned long get___schedule_addr(void)
{
	return kallsyms_lookup_name("__schedule");
}
#else
static unsigned long get___schedule_addr(void)
{
	union mips_instruction *ip = (void *)schedule;
	int max_insns = 8;
	int i;

	for (i = 0; i < max_insns; i++, ip++) {
		if (ip->j_format.opcode == j_op)
			return J_TARGET(ip, ip->j_format.target);
	}
	return 0;
}
#endif

static int __init frame_info_init(void)
{
	unsigned long size = 0;
#ifdef CONFIG_KALLSYMS
	unsigned long ofs;
#endif
	unsigned long addr;

	addr = get___schedule_addr();
	if (!addr)
		addr = (unsigned long)schedule;

#ifdef CONFIG_KALLSYMS
	kallsyms_lookup_size_offset(addr, &size, &ofs);
#endif
	schedule_mfi.func = (void *)addr;
	schedule_mfi.func_size = size;

	get_frame_info(&schedule_mfi);

	/*
	 * Without schedule() frame info, result given by
	 * thread_saved_pc() and get_wchan() are not reliable.
	 */
	if (schedule_mfi.pc_offset < 0)
		printk("Can't analyze schedule() prologue at %p\n", schedule);

	return 0;
}

arch_initcall(frame_info_init);

/*
 * Return saved PC of a blocked thread.
 */
unsigned long thread_saved_pc(struct task_struct *tsk)
{
	struct thread_struct *t = &tsk->thread;

	/* New born processes are a special case */
	if (t->reg31 == (unsigned long) ret_from_fork)
		return t->reg31;
	if (schedule_mfi.pc_offset < 0)
		return 0;
	return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset];
}


#ifdef CONFIG_KALLSYMS
/* generic stack unwinding function */
unsigned long notrace unwind_stack_by_address(unsigned long stack_page,
					      unsigned long *sp,
					      unsigned long pc,
					      unsigned long *ra)
{
	struct mips_frame_info info;
	unsigned long size, ofs;
	int leaf;
	extern void ret_from_irq(void);
	extern void ret_from_exception(void);

	if (!stack_page)
		return 0;

	/*
	 * If we reached the bottom of interrupt context,
	 * return saved pc in pt_regs.
	 */
	if (pc == (unsigned long)ret_from_irq ||
	    pc == (unsigned long)ret_from_exception) {
		struct pt_regs *regs;
		if (*sp >= stack_page &&
		    *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) {
			regs = (struct pt_regs *)*sp;
			pc = regs->cp0_epc;
			if (__kernel_text_address(pc)) {
				*sp = regs->regs[29];
				*ra = regs->regs[31];
				return pc;
			}
		}
		return 0;
	}
	if (!kallsyms_lookup_size_offset(pc, &size, &ofs))
		return 0;
	/*
	 * Return ra if an exception occurred at the first instruction
	 */
	if (unlikely(ofs == 0)) {
		pc = *ra;
		*ra = 0;
		return pc;
	}

	info.func = (void *)(pc - ofs);
	info.func_size = ofs;	/* analyze from start to ofs */
	leaf = get_frame_info(&info);
	if (leaf < 0)
		return 0;

	if (*sp < stack_page ||
	    *sp + info.frame_size > stack_page + THREAD_SIZE - 32)
		return 0;

	if (leaf)
		/*
		 * For some extreme cases, get_frame_info() can
		 * consider wrongly a nested function as a leaf
		 * one. In that cases avoid to return always the
		 * same value.
		 */
		pc = pc != *ra ? *ra : 0;
	else
		pc = ((unsigned long *)(*sp))[info.pc_offset];

	*sp += info.frame_size;
	*ra = 0;
	return __kernel_text_address(pc) ? pc : 0;
}
EXPORT_SYMBOL(unwind_stack_by_address);

/* used by show_backtrace() */
unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
			   unsigned long pc, unsigned long *ra)
{
	unsigned long stack_page = (unsigned long)task_stack_page(task);
	return unwind_stack_by_address(stack_page, sp, pc, ra);
}
#endif

/*
 * get_wchan - a maintenance nightmare^W^Wpain in the ass ...
 */
unsigned long get_wchan(struct task_struct *task)
{
	unsigned long pc = 0;
#ifdef CONFIG_KALLSYMS
	unsigned long sp;
	unsigned long ra = 0;
#endif

	if (!task || task == current || task->state == TASK_RUNNING)
		goto out;
	if (!task_stack_page(task))
		goto out;

	pc = thread_saved_pc(task);

#ifdef CONFIG_KALLSYMS
	sp = task->thread.reg29 + schedule_mfi.frame_size;

	while (in_sched_functions(pc))
		pc = unwind_stack(task, &sp, pc, &ra);
#endif

out:
	return pc;
}

/*
 * Don't forget that the stack pointer must be aligned on a 8 bytes
 * boundary for 32-bits ABI and 16 bytes for 64-bits ABI.
 */
unsigned long arch_align_stack(unsigned long sp)
{
	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
		sp -= get_random_int() & ~PAGE_MASK;

	return sp & ALMASK;
}

static void arch_dump_stack(void *info)
{
	struct pt_regs *regs;

	regs = get_irq_regs();

	if (regs)
		show_regs(regs);

	dump_stack();
}

void arch_trigger_all_cpu_backtrace(bool include_self)
{
	smp_call_function(arch_dump_stack, NULL, 1);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
	6	* Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
40ac5d47	7	* Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
1da177e4 LT	8	* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
1da177e4 LT	9	* Copyright (C) 2004 Thiemo Seufer
34c2f668	10	* Copyright (C) 2013 Imagination Technologies Ltd.
1da177e4	11	*/
1da177e4	12	#include <linux/errno.h>
1da177e4	13	#include <linux/sched.h>
7bcf7717	14	#include <linux/tick.h>
1da177e4 LT	15	#include <linux/kernel.h>
	16	#include <linux/mm.h>
	17	#include <linux/stddef.h>
	18	#include <linux/unistd.h>
cae39d13	19	#include <linux/export.h>
1da177e4	20	#include <linux/ptrace.h>
1da177e4 LT	21	#include <linux/mman.h>
	22	#include <linux/personality.h>
	23	#include <linux/sys.h>
1da177e4 LT	24	#include <linux/init.h>
1da177e4 LT	25	#include <linux/completion.h>
63077519	26	#include <linux/kallsyms.h>
94109102	27	#include <linux/random.h>
1da177e4	28
94109102	29	#include <asm/asm.h>
1da177e4 LT	30	#include <asm/bootinfo.h>
1da177e4 LT	31	#include <asm/cpu.h>
e50c0a8f	32	#include <asm/dsp.h>
1da177e4	33	#include <asm/fpu.h>
1db1af84	34	#include <asm/msa.h>
1da177e4	35	#include <asm/pgtable.h>
1da177e4 LT	36	#include <asm/mipsregs.h>
1da177e4 LT	37	#include <asm/processor.h>
60be939c	38	#include <asm/reg.h>
1da177e4 LT	39	#include <asm/uaccess.h>
	40	#include <asm/io.h>
	41	#include <asm/elf.h>
	42	#include <asm/isadep.h>
	43	#include <asm/inst.h>
1df0f0ff	44	#include <asm/stacktrace.h>
856839b7	45	#include <asm/irq_regs.h>
1da177e4	46
cdbedc61 TG	47	#ifdef CONFIG_HOTPLUG_CPU
cdbedc61 TG	48	void arch_cpu_idle_dead(void)
1da177e4	49	{
cdbedc61 TG	50	/* What the heck is this check doing ? */
	51	if (!cpu_isset(smp_processor_id(), cpu_callin_map))
	52	play_dead();
	53	}
	54	#endif
1b2bc75c	55
1da177e4	56	asmlinkage void ret_from_fork(void);
8f54bcac	57	asmlinkage void ret_from_kernel_thread(void);
1da177e4 LT	58
	59	void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
	60	{
	61	unsigned long status;
	62
	63	/* New thread loses kernel privileges. */
bbaf238b	64	status = regs->cp0_status & ~(ST0_CU0\|ST0_CU1\|ST0_FR\|KU_MASK);
1da177e4 LT	65	status \|= KU_USER;
	66	regs->cp0_status = status;
	67	clear_used_math();
e04582b7	68	clear_fpu_owner();
a3056b1c	69	init_dsp();
7daef8f2	70	clear_thread_flag(TIF_USEDMSA);
1db1af84 PB	71	clear_thread_flag(TIF_MSA_CTX_LIVE);
1db1af84 PB	72	disable_msa();
1da177e4 LT	73	regs->cp0_epc = pc;
1da177e4 LT	74	regs->regs[29] = sp;
1da177e4 LT	75	}
	76
	77	void exit_thread(void)
	78	{
	79	}
	80
	81	void flush_thread(void)
	82	{
	83	}
	84
6f2c55b8	85	int copy_thread(unsigned long clone_flags, unsigned long usp,
afa86fc4	86	unsigned long arg, struct task_struct *p)
1da177e4	87	{
75bb07e7	88	struct thread_info *ti = task_thread_info(p);
afa86fc4	89	struct pt_regs childregs, regs = current_pt_regs();
484889fc	90	unsigned long childksp;
3c37026d	91	p->set_child_tid = p->clear_child_tid = NULL;
1da177e4	92
75bb07e7	93	childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;
1da177e4 LT	94
	95	preempt_disable();
	96
1db1af84 PB	97	if (is_msa_enabled())
	98	save_msa(p);
	99	else if (is_fpu_owner())
1da177e4	100	save_fp(p);
e50c0a8f RB	101
	102	if (cpu_has_dsp)
	103	save_dsp(p);
1da177e4 LT	104
	105	preempt_enable();
	106
	107	/* set up new TSS. */
	108	childregs = (struct pt_regs *) childksp - 1;
484889fc DD	109	/* Put the stack after the struct pt_regs. */
484889fc DD	110	childksp = (unsigned long) childregs;
8f54bcac AV	111	p->thread.cp0_status = read_c0_status() & ~(ST0_CU2\|ST0_CU1);
	112	if (unlikely(p->flags & PF_KTHREAD)) {
	113	unsigned long status = p->thread.cp0_status;
	114	memset(childregs, 0, sizeof(struct pt_regs));
	115	ti->addr_limit = KERNEL_DS;
	116	p->thread.reg16 = usp; /* fn */
	117	p->thread.reg17 = arg;
	118	p->thread.reg29 = childksp;
	119	p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
	120	#if defined(CONFIG_CPU_R3000) \|\| defined(CONFIG_CPU_TX39XX)
	121	status = (status & ~(ST0_KUP \| ST0_IEP \| ST0_IEC)) \|
	122	((status & (ST0_KUC \| ST0_IEC)) << 2);
	123	#else
	124	status \|= ST0_EXL;
	125	#endif
	126	childregs->cp0_status = status;
	127	return 0;
	128	}
1da177e4	129	childregs = regs;
70342287 RB	130	childregs->regs[7] = 0; /* Clear error flag */
70342287 RB	131	childregs->regs[2] = 0; /* Child gets zero as return value */
64b3122d AV	132	if (usp)
64b3122d AV	133	childregs->regs[29] = usp;
8f54bcac	134	ti->addr_limit = USER_DS;
1da177e4	135
1da177e4 LT	136	p->thread.reg29 = (unsigned long) childregs;
	137	p->thread.reg31 = (unsigned long) ret_from_fork;
	138
	139	/*
	140	* New tasks lose permission to use the fpu. This accelerates context
	141	* switching for most programs since they don't use the fpu.
	142	*/
1da177e4	143	childregs->cp0_status &= ~(ST0_CU2\|ST0_CU1);
1da177e4	144
1da177e4	145	clear_tsk_thread_flag(p, TIF_USEDFPU);
7daef8f2 PB	146	clear_tsk_thread_flag(p, TIF_USEDMSA);
7daef8f2 PB	147	clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE);
1da177e4	148
f088fc84	149	#ifdef CONFIG_MIPS_MT_FPAFF
6657fe0a	150	clear_tsk_thread_flag(p, TIF_FPUBOUND);
f088fc84 RB	151	#endif /* CONFIG_MIPS_MT_FPAFF */
f088fc84 RB	152
3c37026d RB	153	if (clone_flags & CLONE_SETTLS)
	154	ti->tp_value = regs->regs[7];
	155
1da177e4 LT	156	return 0;
	157	}
	158
36ecafc5 GF	159	#ifdef CONFIG_CC_STACKPROTECTOR
	160	#include <linux/stackprotector.h>
	161	unsigned long __stack_chk_guard __read_mostly;
	162	EXPORT_SYMBOL(__stack_chk_guard);
	163	#endif
	164
b5943182 FBH	165	struct mips_frame_info {
	166	void *func;
	167	unsigned long func_size;
	168	int frame_size;
	169	int pc_offset;
	170	};
dc953df1	171
5000653e TW	172	#define J_TARGET(pc,target) \
	173	(((unsigned long)(pc) & 0xf0000000) \| ((target) << 2))
	174
c0efbb6d FBH	175	static inline int is_ra_save_ins(union mips_instruction *ip)
c0efbb6d FBH	176	{
34c2f668 LY	177	#ifdef CONFIG_CPU_MICROMIPS
	178	union mips_instruction mmi;
	179
	180	/*
	181	* swsp ra,offset
	182	* swm16 reglist,offset(sp)
	183	* swm32 reglist,offset(sp)
	184	* sw32 ra,offset(sp)
	185	* jradiussp - NOT SUPPORTED
	186	*
	187	* microMIPS is way more fun...
	188	*/
	189	if (mm_insn_16bit(ip->halfword[0])) {
	190	mmi.word = (ip->halfword[0] << 16);
635c9907 RB	191	return (mmi.mm16_r5_format.opcode == mm_swsp16_op &&
	192	mmi.mm16_r5_format.rt == 31) \|\|
	193	(mmi.mm16_m_format.opcode == mm_pool16c_op &&
	194	mmi.mm16_m_format.func == mm_swm16_op);
34c2f668 LY	195	}
	196	else {
	197	mmi.halfword[0] = ip->halfword[1];
	198	mmi.halfword[1] = ip->halfword[0];
635c9907 RB	199	return (mmi.mm_m_format.opcode == mm_pool32b_op &&
	200	mmi.mm_m_format.rd > 9 &&
	201	mmi.mm_m_format.base == 29 &&
	202	mmi.mm_m_format.func == mm_swm32_func) \|\|
	203	(mmi.i_format.opcode == mm_sw32_op &&
	204	mmi.i_format.rs == 29 &&
	205	mmi.i_format.rt == 31);
34c2f668 LY	206	}
34c2f668 LY	207	#else
c0efbb6d FBH	208	/* sw / sd $ra, offset($sp) */
	209	return (ip->i_format.opcode == sw_op \|\| ip->i_format.opcode == sd_op) &&
	210	ip->i_format.rs == 29 &&
	211	ip->i_format.rt == 31;
34c2f668	212	#endif
c0efbb6d FBH	213	}
c0efbb6d FBH	214
e7438c4b	215	static inline int is_jump_ins(union mips_instruction *ip)
c0efbb6d	216	{
34c2f668 LY	217	#ifdef CONFIG_CPU_MICROMIPS
	218	/*
	219	* jr16,jrc,jalr16,jalr16
	220	* jal
	221	* jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb
	222	* jraddiusp - NOT SUPPORTED
	223	*
	224	* microMIPS is kind of more fun...
	225	*/
	226	union mips_instruction mmi;
	227
	228	mmi.word = (ip->halfword[0] << 16);
	229
	230	if ((mmi.mm16_r5_format.opcode == mm_pool16c_op &&
	231	(mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) \|\|
	232	ip->j_format.opcode == mm_jal32_op)
	233	return 1;
	234	if (ip->r_format.opcode != mm_pool32a_op \|\|
	235	ip->r_format.func != mm_pool32axf_op)
	236	return 0;
635c9907	237	return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op;
34c2f668	238	#else
e7438c4b TW	239	if (ip->j_format.opcode == j_op)
e7438c4b TW	240	return 1;
c0efbb6d FBH	241	if (ip->j_format.opcode == jal_op)
	242	return 1;
	243	if (ip->r_format.opcode != spec_op)
	244	return 0;
	245	return ip->r_format.func == jalr_op \|\| ip->r_format.func == jr_op;
34c2f668	246	#endif
c0efbb6d FBH	247	}
	248
	249	static inline int is_sp_move_ins(union mips_instruction *ip)
	250	{
34c2f668 LY	251	#ifdef CONFIG_CPU_MICROMIPS
	252	/*
	253	* addiusp -imm
	254	* addius5 sp,-imm
	255	* addiu32 sp,sp,-imm
	256	* jradiussp - NOT SUPPORTED
	257	*
	258	* microMIPS is not more fun...
	259	*/
	260	if (mm_insn_16bit(ip->halfword[0])) {
	261	union mips_instruction mmi;
	262
	263	mmi.word = (ip->halfword[0] << 16);
635c9907 RB	264	return (mmi.mm16_r3_format.opcode == mm_pool16d_op &&
	265	mmi.mm16_r3_format.simmediate && mm_addiusp_func) \|\|
	266	(mmi.mm16_r5_format.opcode == mm_pool16d_op &&
	267	mmi.mm16_r5_format.rt == 29);
34c2f668	268	}
635c9907 RB	269	return ip->mm_i_format.opcode == mm_addiu32_op &&
635c9907 RB	270	ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29;
34c2f668	271	#else
c0efbb6d FBH	272	/* addiu/daddiu sp,sp,-imm */
	273	if (ip->i_format.rs != 29 \|\| ip->i_format.rt != 29)
	274	return 0;
	275	if (ip->i_format.opcode == addiu_op \|\| ip->i_format.opcode == daddiu_op)
	276	return 1;
34c2f668	277	#endif
c0efbb6d FBH	278	return 0;
	279	}
	280
f66686f7	281	static int get_frame_info(struct mips_frame_info *info)
1da177e4	282	{
34c2f668 LY	283	#ifdef CONFIG_CPU_MICROMIPS
	284	union mips_instruction ip = (void ) (((char *) info->func) - 1);
	285	#else
c0efbb6d	286	union mips_instruction *ip = info->func;
34c2f668	287	#endif
29b376ff FBH	288	unsigned max_insns = info->func_size / sizeof(union mips_instruction);
29b376ff FBH	289	unsigned i;
c0efbb6d	290
1da177e4	291	info->pc_offset = -1;
63077519	292	info->frame_size = 0;
1da177e4	293
29b376ff FBH	294	if (!ip)
	295	goto err;
	296
	297	if (max_insns == 0)
	298	max_insns = 128U; /* unknown function size */
	299	max_insns = min(128U, max_insns);
	300
c0efbb6d FBH	301	for (i = 0; i < max_insns; i++, ip++) {
c0efbb6d FBH	302
e7438c4b	303	if (is_jump_ins(ip))
63077519	304	break;
0cceb4aa FBH	305	if (!info->frame_size) {
0cceb4aa FBH	306	if (is_sp_move_ins(ip))
34c2f668 LY	307	{
	308	#ifdef CONFIG_CPU_MICROMIPS
	309	if (mm_insn_16bit(ip->halfword[0]))
	310	{
	311	unsigned short tmp;
	312
	313	if (ip->halfword[0] & mm_addiusp_func)
	314	{
	315	tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2);
	316	info->frame_size = -(signed short)(tmp \| ((tmp & 0x100) ? 0xfe00 : 0));
	317	} else {
	318	tmp = (ip->halfword[0] >> 1);
	319	info->frame_size = -(signed short)(tmp & 0xf);
	320	}
	321	ip = (void *) &ip->halfword[1];
	322	ip--;
	323	} else
	324	#endif
0cceb4aa	325	info->frame_size = - ip->i_format.simmediate;
34c2f668	326	}
0cceb4aa	327	continue;
63077519	328	}
0cceb4aa	329	if (info->pc_offset == -1 && is_ra_save_ins(ip)) {
63077519 AN	330	info->pc_offset =
63077519 AN	331	ip->i_format.simmediate / sizeof(long);
0cceb4aa	332	break;
1da177e4 LT	333	}
1da177e4 LT	334	}
f66686f7 AN	335	if (info->frame_size && info->pc_offset >= 0) /* nested */
	336	return 0;
	337	if (info->pc_offset < 0) /* leaf */
	338	return 1;
	339	/* prologue seems boggus... */
29b376ff	340	err:
f66686f7	341	return -1;
1da177e4 LT	342	}
1da177e4 LT	343
b5943182 FBH	344	static struct mips_frame_info schedule_mfi __read_mostly;
b5943182 FBH	345
5000653e TW	346	#ifdef CONFIG_KALLSYMS
	347	static unsigned long get___schedule_addr(void)
	348	{
	349	return kallsyms_lookup_name("__schedule");
	350	}
	351	#else
	352	static unsigned long get___schedule_addr(void)
	353	{
	354	union mips_instruction ip = (void )schedule;
	355	int max_insns = 8;
	356	int i;
	357
	358	for (i = 0; i < max_insns; i++, ip++) {
	359	if (ip->j_format.opcode == j_op)
	360	return J_TARGET(ip, ip->j_format.target);
	361	}
	362	return 0;
	363	}
	364	#endif
	365
1da177e4 LT	366	static int __init frame_info_init(void)
1da177e4 LT	367	{
b5943182	368	unsigned long size = 0;
63077519	369	#ifdef CONFIG_KALLSYMS
b5943182	370	unsigned long ofs;
5000653e TW	371	#endif
5000653e TW	372	unsigned long addr;
b5943182	373
5000653e TW	374	addr = get___schedule_addr();
	375	if (!addr)
	376	addr = (unsigned long)schedule;
	377
	378	#ifdef CONFIG_KALLSYMS
	379	kallsyms_lookup_size_offset(addr, &size, &ofs);
63077519	380	#endif
5000653e	381	schedule_mfi.func = (void *)addr;
b5943182 FBH	382	schedule_mfi.func_size = size;
	383
	384	get_frame_info(&schedule_mfi);
6057a798 FBH	385
	386	/*
	387	* Without schedule() frame info, result given by
	388	* thread_saved_pc() and get_wchan() are not reliable.
	389	*/
b5943182	390	if (schedule_mfi.pc_offset < 0)
6057a798	391	printk("Can't analyze schedule() prologue at %p\n", schedule);
63077519	392
1da177e4 LT	393	return 0;
	394	}
	395
	396	arch_initcall(frame_info_init);
	397
	398	/*
	399	* Return saved PC of a blocked thread.
	400	*/
	401	unsigned long thread_saved_pc(struct task_struct *tsk)
	402	{
	403	struct thread_struct *t = &tsk->thread;
	404
	405	/* New born processes are a special case */
	406	if (t->reg31 == (unsigned long) ret_from_fork)
	407	return t->reg31;
b5943182	408	if (schedule_mfi.pc_offset < 0)
1da177e4	409	return 0;
b5943182	410	return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset];
1da177e4 LT	411	}
1da177e4 LT	412
1da177e4	413
f66686f7	414	#ifdef CONFIG_KALLSYMS
94ea09c6 DK	415	/* generic stack unwinding function */
	416	unsigned long notrace unwind_stack_by_address(unsigned long stack_page,
	417	unsigned long *sp,
	418	unsigned long pc,
	419	unsigned long *ra)
f66686f7	420	{
f66686f7	421	struct mips_frame_info info;
f66686f7	422	unsigned long size, ofs;
4d157d5e	423	int leaf;
1924600c AN	424	extern void ret_from_irq(void);
1924600c AN	425	extern void ret_from_exception(void);
f66686f7	426
f66686f7 AN	427	if (!stack_page)
	428	return 0;
	429
1924600c AN	430	/*
	431	* If we reached the bottom of interrupt context,
	432	* return saved pc in pt_regs.
	433	*/
	434	if (pc == (unsigned long)ret_from_irq \|\|
	435	pc == (unsigned long)ret_from_exception) {
	436	struct pt_regs *regs;
	437	if (*sp >= stack_page &&
	438	sp + sizeof(regs) <= stack_page + THREAD_SIZE - 32) {
	439	regs = (struct pt_regs )sp;
	440	pc = regs->cp0_epc;
	441	if (__kernel_text_address(pc)) {
	442	*sp = regs->regs[29];
	443	*ra = regs->regs[31];
	444	return pc;
	445	}
	446	}
	447	return 0;
	448	}
55b74283	449	if (!kallsyms_lookup_size_offset(pc, &size, &ofs))
f66686f7	450	return 0;
1fd69098	451	/*
25985edc	452	* Return ra if an exception occurred at the first instruction
1fd69098	453	*/
1924600c AN	454	if (unlikely(ofs == 0)) {
	455	pc = *ra;
	456	*ra = 0;
	457	return pc;
	458	}
f66686f7 AN	459
	460	info.func = (void *)(pc - ofs);
	461	info.func_size = ofs; /* analyze from start to ofs */
4d157d5e FBH	462	leaf = get_frame_info(&info);
4d157d5e FBH	463	if (leaf < 0)
f66686f7	464	return 0;
4d157d5e FBH	465
	466	if (*sp < stack_page \|\|
	467	*sp + info.frame_size > stack_page + THREAD_SIZE - 32)
f66686f7 AN	468	return 0;
f66686f7 AN	469
4d157d5e FBH	470	if (leaf)
	471	/*
	472	* For some extreme cases, get_frame_info() can
	473	* consider wrongly a nested function as a leaf
	474	* one. In that cases avoid to return always the
	475	* same value.
	476	*/
1924600c	477	pc = pc != ra ? ra : 0;
4d157d5e FBH	478	else
	479	pc = ((unsigned long )(sp))[info.pc_offset];
	480
	481	*sp += info.frame_size;
1924600c	482	*ra = 0;
4d157d5e	483	return __kernel_text_address(pc) ? pc : 0;
f66686f7	484	}
94ea09c6 DK	485	EXPORT_SYMBOL(unwind_stack_by_address);
	486
	487	/* used by show_backtrace() */
	488	unsigned long unwind_stack(struct task_struct task, unsigned long sp,
	489	unsigned long pc, unsigned long *ra)
	490	{
	491	unsigned long stack_page = (unsigned long)task_stack_page(task);
	492	return unwind_stack_by_address(stack_page, sp, pc, ra);
	493	}
f66686f7	494	#endif
b5943182 FBH	495
	496	/*
	497	* get_wchan - a maintenance nightmare^W^Wpain in the ass ...
	498	*/
	499	unsigned long get_wchan(struct task_struct *task)
	500	{
	501	unsigned long pc = 0;
	502	#ifdef CONFIG_KALLSYMS
	503	unsigned long sp;
1924600c	504	unsigned long ra = 0;
b5943182 FBH	505	#endif
	506
	507	if (!task \|\| task == current \|\| task->state == TASK_RUNNING)
	508	goto out;
	509	if (!task_stack_page(task))
	510	goto out;
	511
	512	pc = thread_saved_pc(task);
	513
	514	#ifdef CONFIG_KALLSYMS
	515	sp = task->thread.reg29 + schedule_mfi.frame_size;
	516
	517	while (in_sched_functions(pc))
1924600c	518	pc = unwind_stack(task, &sp, pc, &ra);
b5943182 FBH	519	#endif
	520
	521	out:
	522	return pc;
	523	}
94109102 FBH	524
	525	/*
	526	* Don't forget that the stack pointer must be aligned on a 8 bytes
	527	* boundary for 32-bits ABI and 16 bytes for 64-bits ABI.
	528	*/
	529	unsigned long arch_align_stack(unsigned long sp)
	530	{
	531	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
	532	sp -= get_random_int() & ~PAGE_MASK;
	533
	534	return sp & ALMASK;
	535	}
856839b7 ES	536
	537	static void arch_dump_stack(void *info)
	538	{
	539	struct pt_regs *regs;
	540
	541	regs = get_irq_regs();
	542
	543	if (regs)
	544	show_regs(regs);
	545
	546	dump_stack();
	547	}
	548
	549	void arch_trigger_all_cpu_backtrace(bool include_self)
	550	{
	551	smp_call_function(arch_dump_stack, NULL, 1);
	552	}