cregit-Linux how code gets into the kernel

Release 4.14 arch/mips/kernel/process.c

Directory: arch/mips/kernel
/*
 * 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/sched/debug.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.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 <linux/prctl.h>

#include <asm/asm.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
#include <asm/dsemul.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/irq.h>
#include <asm/msa.h>
#include <asm/pgtable.h>
#include <asm/mipsregs.h>
#include <asm/processor.h>
#include <asm/reg.h>
#include <linux/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)
{
	play_dead();
}

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Linus Torvalds (pre-git)550.00%150.00%


Thomas Gleixner550.00%150.00%


Total10100.00%2100.00%



#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;
	lose_fpu(0);
	clear_thread_flag(TIF_MSA_CTX_LIVE);
	clear_used_math();
	atomic_set(&current->thread.bd_emu_frame, BD_EMUFRAME_NONE);
	init_dsp();
	regs->cp0_epc = pc;
	regs->regs[29] = sp;
}


Contributors
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Ralf Bächle5660.22%222.22%


Paul Burton2223.66%333.33%


Linus Torvalds (pre-git)77.53%222.22%


James Hogan66.45%111.11%


Chris Dearman22.15%111.11%


Total93100.00%9100.00%






void exit_thread(struct task_struct *tsk)
{
	/*
         * User threads may have allocated a delay slot emulation frame.
         * If so, clean up that allocation.
         */
	if (!(current->flags & PF_KTHREAD))
		dsemul_thread_cleanup(tsk);
}


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Total27100.00%1100.00%






int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
	/*
         * Save any process state which is live in hardware registers to the
         * parent context prior to duplication. This prevents the new child
         * state becoming stale if the parent is preempted before copy_thread()
         * gets a chance to save the parent's live hardware registers to the
         * child context.
         */
	preempt_disable();

	if (is_msa_enabled())
		save_msa(current);
	else if (is_fpu_owner())
		_save_fp(current);

	save_dsp(current);

	preempt_enable();

	*dst = *src;
	return 0;
}


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Total57100.00%1100.00%



/*
 * Copy architecture-specific thread state
 */



int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
	unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
{
	struct thread_info *ti = task_thread_info(p);
	struct pt_regs *childregs, *regs = current_pt_regs();
	unsigned long childksp;

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

	/* 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)) {
		/* kernel thread */
		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 = kthread_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;
	}

	/* user thread */
	*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 */

	atomic_set(&p->thread.bd_emu_frame, BD_EMUFRAME_NONE);

	if (clone_flags & CLONE_SETTLS)
		ti->tp_value = tls;

	return 0;
}


Contributors
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Al Viro16743.60%417.39%


Linus Torvalds (pre-git)12833.42%834.78%


Ralf Bächle4110.70%521.74%


Paul Burton266.79%28.70%


David Daney102.61%14.35%


James Cowgill61.57%14.35%


Alex Dowad41.04%14.35%


Steven Cole10.26%14.35%


Total383100.00%23100.00%



#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, int *poff)
{
#ifdef CONFIG_CPU_MICROMIPS
	/*
         * 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->word >> 16)) {
		switch (ip->mm16_r5_format.opcode) {
		case mm_swsp16_op:
			if (ip->mm16_r5_format.rt != 31)
				return 0;

			*poff = ip->mm16_r5_format.imm;
			*poff = (*poff << 2) / sizeof(ulong);
			return 1;

		case mm_pool16c_op:
			switch (ip->mm16_m_format.func) {
			case mm_swm16_op:
				*poff = ip->mm16_m_format.imm;
				*poff += 1 + ip->mm16_m_format.rlist;
				*poff = (*poff << 2) / sizeof(ulong);
				return 1;

			default:
				return 0;
			}

		default:
			return 0;
		}
	}

	switch (ip->i_format.opcode) {
	case mm_sw32_op:
		if (ip->i_format.rs != 29)
			return 0;
		if (ip->i_format.rt != 31)
			return 0;

		*poff = ip->i_format.simmediate / sizeof(ulong);
		return 1;

	case mm_pool32b_op:
		switch (ip->mm_m_format.func) {
		case mm_swm32_func:
			if (ip->mm_m_format.rd < 0x10)
				return 0;
			if (ip->mm_m_format.base != 29)
				return 0;

			*poff = ip->mm_m_format.simmediate;
			*poff += (ip->mm_m_format.rd & 0xf) * sizeof(u32);
			*poff /= sizeof(ulong);
			return 1;
		default:
			return 0;
		}

	default:
		return 0;
	}
#else
	/* sw / sd $ra, offset($sp) */
	if ((ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
		ip->i_format.rs == 29 && ip->i_format.rt == 31) {
		*poff = ip->i_format.simmediate / sizeof(ulong);
		return 1;
	}

	return 0;
#endif
}


Contributors
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Paul Burton25270.99%225.00%


Leonid Yegoshin5214.65%112.50%


Franck Bui-Huu3610.14%112.50%


Ralf Bächle102.82%112.50%


Matt Redfearn41.13%225.00%


Linus Torvalds (pre-git)10.28%112.50%


Total355100.00%8100.00%






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...
         */
	if (mm_insn_16bit(ip->word >> 16)) {
		if ((ip->mm16_r5_format.opcode == mm_pool16c_op &&
		    (ip->mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op))
			return 1;
		return 0;
	}

	if (ip->j_format.opcode == mm_j32_op)
		return 1;
	if (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
}


Contributors
PersonTokensPropCommitsCommitProp
Leonid Yegoshin7641.53%111.11%


Paul Burton3619.67%333.33%


Ralf Bächle2915.85%111.11%


Franck Bui-Huu2212.02%111.11%


Tony Wu147.65%111.11%


Linus Torvalds (pre-git)31.64%111.11%


Matt Redfearn31.64%111.11%


Total183100.00%9100.00%






static inline int is_sp_move_ins(union mips_instruction *ip, int *frame_size)
{
#ifdef CONFIG_CPU_MICROMIPS
	unsigned short tmp;

	/*
         * addiusp -imm
         * addius5 sp,-imm
         * addiu32 sp,sp,-imm
         * jradiussp - NOT SUPPORTED
         *
         * microMIPS is not more fun...
         */
	if (mm_insn_16bit(ip->word >> 16)) {
		if (ip->mm16_r3_format.opcode == mm_pool16d_op &&
		    ip->mm16_r3_format.simmediate & mm_addiusp_func) {
			tmp = ip->mm_b0_format.simmediate >> 1;
			tmp = ((tmp & 0x1ff) ^ 0x100) - 0x100;
			if ((tmp + 2) < 4) /* 0x0,0x1,0x1fe,0x1ff are special */
				tmp ^= 0x100;
			*frame_size = -(signed short)(tmp << 2);
			return 1;
		}
		if (ip->mm16_r5_format.opcode == mm_pool16d_op &&
		    ip->mm16_r5_format.rt == 29) {
			tmp = ip->mm16_r5_format.imm >> 1;
			*frame_size = -(signed short)(tmp & 0xf);
			return 1;
		}
		return 0;
	}

	if (ip->mm_i_format.opcode == mm_addiu32_op &&
	    ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29) {
		*frame_size = -ip->i_format.simmediate;
		return 1;
	}
#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) {
		*frame_size = -ip->i_format.simmediate;
		return 1;
	}
#endif
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Matt Redfearn13350.00%330.00%


Leonid Yegoshin6925.94%110.00%


Franck Bui-Huu3713.91%110.00%


Ralf Bächle134.89%220.00%


Atsushi Nemoto72.63%110.00%


Paul Burton62.26%110.00%


Linus Torvalds (pre-git)10.38%110.00%


Total266100.00%10100.00%






static int get_frame_info(struct mips_frame_info *info)
{
	bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS);
	union mips_instruction insn, *ip, *ip_end;
	const unsigned int max_insns = 128;
	unsigned int last_insn_size = 0;
	unsigned int i;
	bool saw_jump = false;

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

	ip = (void *)msk_isa16_mode((ulong)info->func);
	if (!ip)
		goto err;

	ip_end = (void *)ip + info->func_size;

	for (i = 0; i < max_insns && ip < ip_end; i++) {
		ip = (void *)ip + last_insn_size;
		if (is_mmips && mm_insn_16bit(ip->halfword[0])) {
			insn.word = ip->halfword[0] << 16;
			last_insn_size = 2;
		} else if (is_mmips) {
			insn.word = ip->halfword[0] << 16 | ip->halfword[1];
			last_insn_size = 4;
		} else {
			insn.word = ip->word;
			last_insn_size = 4;
		}

		if (!info->frame_size) {
			is_sp_move_ins(&insn, &info->frame_size);
			continue;
		} else if (!saw_jump && is_jump_ins(ip)) {
			/*
                         * If we see a jump instruction, we are finished
                         * with the frame save.
                         *
                         * Some functions can have a shortcut return at
                         * the beginning of the function, so don't start
                         * looking for jump instruction until we see the
                         * frame setup.
                         *
                         * The RA save instruction can get put into the
                         * delay slot of the jump instruction, so look
                         * at the next instruction, too.
                         */
			saw_jump = true;
			continue;
		}
		if (info->pc_offset == -1 &&
		    is_ra_save_ins(&insn, &info->pc_offset))
			break;
		if (saw_jump)
			break;
	}
	if (info->frame_size && info->pc_offset >= 0) /* nested */
		return 0;
	if (info->pc_offset < 0) /* leaf */
		return 1;
	/* prologue seems bogus... */
err:
	return -1;
}


Contributors
PersonTokensPropCommitsCommitProp
Paul Burton11035.60%423.53%


Franck Bui-Huu7223.30%317.65%


Matt Redfearn3812.30%317.65%


Corey Minyard299.39%15.88%


Ralf Bächle227.12%15.88%


Atsushi Nemoto227.12%211.76%


Leonid Yegoshin113.56%15.88%


Linus Torvalds (pre-git)41.29%15.88%


Andrea Gelmini10.32%15.88%


Total309100.00%17100.00%




static struct mips_frame_info schedule_mfi __read_mostly;

#ifdef CONFIG_KALLSYMS



static unsigned long get___schedule_addr(void)
{
	return kallsyms_lookup_name("__schedule");
}

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Total15100.00%1100.00%



#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;
}

Contributors
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Tony Wu71100.00%1100.00%


Total71100.00%1100.00%



#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;
}


Contributors
PersonTokensPropCommitsCommitProp
Atsushi Nemoto3433.01%220.00%


Tony Wu3029.13%110.00%


Franck Bui-Huu2524.27%220.00%


Ralf Bächle65.83%110.00%


Andrew Morton54.85%110.00%


Linus Torvalds (pre-git)21.94%220.00%


Thiemo Seufer10.97%110.00%


Total103100.00%10100.00%




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];
}



Contributors
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Ralf Bächle5582.09%233.33%


Linus Torvalds (pre-git)811.94%233.33%


Franck Bui-Huu34.48%116.67%


Linus Torvalds11.49%116.67%


Total67100.00%6100.00%



#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)
{
	unsigned long low, high, irq_stack_high;
	struct mips_frame_info info;
	unsigned long size, ofs;
	struct pt_regs *regs;
	int leaf;

	if (!stack_page)
		return 0;

	/*
         * IRQ stacks start at IRQ_STACK_START
         * task stacks at THREAD_SIZE - 32
         */
	low = stack_page;
	if (!preemptible() && on_irq_stack(raw_smp_processor_id(), *sp)) {
		high = stack_page + IRQ_STACK_START;
		irq_stack_high = high;
	} else {
		high = stack_page + THREAD_SIZE - 32;
		irq_stack_high = 0;
	}

	/*
         * If we reached the top of the interrupt stack, start unwinding
         * the interrupted task stack.
         */
	if (unlikely(*sp == irq_stack_high)) {
		unsigned long task_sp = *(unsigned long *)*sp;

		/*
                 * Check that the pointer saved in the IRQ stack head points to
                 * something within the stack of the current task
                 */
		if (!object_is_on_stack((void *)task_sp))
			return 0;

		/*
                 * Follow pointer to tasks kernel stack frame where interrupted
                 * state was saved.
                 */
		regs = (struct pt_regs *)task_sp;
		pc = regs->cp0_epc;
		if (!user_mode(regs) && __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 < low || *sp + info.frame_size > high)
		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;
}

Contributors
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Atsushi Nemoto21258.40%222.22%


Matt Redfearn8924.52%111.11%


Franck Bui-Huu5013.77%333.33%


James Hogan61.65%111.11%


Daniel Kalmar51.38%111.11%


Lucas De Marchi10.28%111.11%


Total363100.00%9100.00%




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 = 0;
	int cpu;

	for_each_possible_cpu(cpu) {
		if (on_irq_stack(cpu, *sp)) {
			stack_page = (unsigned long)irq_stack[cpu];
			break;
		}
	}

	if (!stack_page)
		stack_page = (unsigned long)task_stack_page(task);

	return unwind_stack_by_address(stack_page, sp, pc, ra);
}

Contributors
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Daniel Kalmar4953.26%150.00%


Matt Redfearn4346.74%150.00%


Total92100.00%2100.00%



#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;
}


Contributors
PersonTokensPropCommitsCommitProp
Franck Bui-Huu10492.86%150.00%


Atsushi Nemoto87.14%150.00%


Total112100.00%2100.00%



/*
 * 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;
}


Contributors
PersonTokensPropCommitsCommitProp
Franck Bui-Huu36100.00%1100.00%


Total36100.00%1100.00%






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

	regs = get_irq_regs();

	if (regs)
		show_regs(regs);

	dump_stack();
}


Contributors
PersonTokensPropCommitsCommitProp
Eunbong Song 송은봉32100.00%1100.00%


Total32100.00%1100.00%






void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
{
	long this_cpu = get_cpu();

	if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
		dump_stack();

	smp_call_function_many(mask, arch_dump_stack, NULL, 1);

	put_cpu();
}


Contributors
PersonTokensPropCommitsCommitProp
Chris Metcalf3470.83%150.00%


Eunbong Song 송은봉1429.17%150.00%


Total48100.00%2100.00%






int mips_get_process_fp_mode(struct task_struct *task)
{
	int value = 0;

	if (!test_tsk_thread_flag(task, TIF_32BIT_FPREGS))
		value |= PR_FP_MODE_FR;
	if (test_tsk_thread_flag(task, TIF_HYBRID_FPREGS))
		value |= PR_FP_MODE_FRE;

	return value;
}


Contributors
PersonTokensPropCommitsCommitProp
Paul Burton45100.00%1100.00%


Total45100.00%1100.00%






static void prepare_for_fp_mode_switch(void *info)
{
	struct mm_struct *mm = info;

	if (current->mm == mm)
		lose_fpu(1);
}


Contributors
PersonTokensPropCommitsCommitProp
Paul Burton30100.00%1100.00%


Total30100.00%1100.00%






int mips_set_process_fp_mode(struct task_struct *task, unsigned int value)
{
	const unsigned int known_bits = PR_FP_MODE_FR | PR_FP_MODE_FRE;
	struct task_struct *t;
	int max_users;

	/* Check the value is valid */
	if (value & ~known_bits)
		return -EOPNOTSUPP;

	/* Avoid inadvertently triggering emulation */
	if ((value & PR_FP_MODE_FR) && raw_cpu_has_fpu &&
	    !(raw_current_cpu_data.fpu_id & MIPS_FPIR_F64))
		return -EOPNOTSUPP;
	if ((value & PR_FP_MODE_FRE) && raw_cpu_has_fpu && !cpu_has_fre)
		return -EOPNOTSUPP;

	/* FR = 0 not supported in MIPS R6 */
	if (!(value & PR_FP_MODE_FR) && raw_cpu_has_fpu && cpu_has_mips_r6)
		return -EOPNOTSUPP;

	/* Proceed with the mode switch */
	preempt_disable();

	/* Save FP & vector context, then disable FPU & MSA */
	if (task->signal == current->signal)
		lose_fpu(1);

	/* Prevent any threads from obtaining live FP context */
	atomic_set(&task->mm->context.fp_mode_switching, 1);
	smp_mb__after_atomic();

	/*
         * If there are multiple online CPUs then force any which are running
         * threads in this process to lose their FPU context, which they can't
         * regain until fp_mode_switching is cleared later.
         */
	if (num_online_cpus() > 1) {
		/* No need to send an IPI for the local CPU */
		max_users = (task->mm == current->mm) ? 1 : 0;

		if (atomic_read(&current->mm->mm_users) > max_users)
			smp_call_function(prepare_for_fp_mode_switch,
					  (void *)current->mm, 1);
	}

	/*
         * There are now no threads of the process with live FP context, so it
         * is safe to proceed with the FP mode switch.
         */
	for_each_thread(task, t) {
		/* Update desired FP register width */
		if (value & PR_FP_MODE_FR) {
			clear_tsk_thread_flag(t, TIF_32BIT_FPREGS);
		} else {
			set_tsk_thread_flag(t, TIF_32BIT_FPREGS);
			clear_tsk_thread_flag(t, TIF_MSA_CTX_LIVE);
		}

		/* Update desired FP single layout */
		if (value & PR_FP_MODE_FRE)
			set_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
		else
			clear_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
	}

	/* Allow threads to use FP again */
	atomic_set(&task->mm->context.fp_mode_switching, 0);
	preempt_enable();

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Paul Burton26092.53%360.00%


Markos Chandras176.05%120.00%


Marcin Nowakowski41.42%120.00%


Total281100.00%5100.00%



#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)



void mips_dump_regs32(u32 *uregs, const struct pt_regs *regs)
{
	unsigned int i;

	for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) {
		/* k0/k1 are copied as zero. */
		if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27)
			uregs[i] = 0;
		else
			uregs[i] = regs->regs[i - MIPS32_EF_R0];
	}

	uregs[MIPS32_EF_LO] = regs->lo;
	uregs[MIPS32_EF_HI] = regs->hi;
	uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc;
	uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
	uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status;
	uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause;
}

Contributors
PersonTokensPropCommitsCommitProp
Marcin Nowakowski121100.00%1100.00%


Total121100.00%1100.00%



#endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */

#ifdef CONFIG_64BIT



void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs)
{
	unsigned int i;

	for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) {
		/* k0/k1 are copied as zero. */
		if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27)
			uregs[i] = 0;
		else
			uregs[i] = regs->regs[i - MIPS64_EF_R0];
	}

	uregs[MIPS64_EF_LO] = regs->lo;
	uregs[MIPS64_EF_HI] = regs->hi;
	uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc;
	uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
	uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status;
	uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause;
}

Contributors
PersonTokensPropCommitsCommitProp
Marcin Nowakowski121100.00%1100.00%


Total121100.00%1100.00%



#endif /* CONFIG_64BIT */

Overall Contributors
PersonTokensPropCommitsCommitProp
Paul Burton82323.80%1214.12%


Franck Bui-Huu39911.54%910.59%


Matt Redfearn3139.05%78.24%


Atsushi Nemoto2988.62%44.71%


Marcin Nowakowski2667.69%22.35%


Ralf Bächle2647.63%78.24%


Linus Torvalds (pre-git)2156.22%1011.76%


Leonid Yegoshin2096.04%11.18%


Al Viro1745.03%44.71%


Tony Wu1474.25%22.35%


James Hogan692.00%33.53%


Daniel Kalmar611.76%11.18%


Eunbong Song 송은봉491.42%11.18%


Chris Metcalf340.98%11.18%


Corey Minyard290.84%11.18%


Gregory Fong180.52%11.18%


Markos Chandras170.49%11.18%


Andrew Morton100.29%11.18%


Thomas Gleixner100.29%11.18%


David Daney100.29%11.18%


Ingo Molnar90.26%33.53%


Thiemo Seufer70.20%11.18%


James Cowgill60.17%11.18%


Linus Torvalds50.14%33.53%


Alex Dowad50.14%11.18%


Paul Gortmaker30.09%11.18%


Alex Smith30.09%11.18%


Chris Dearman20.06%11.18%


Steven Cole10.03%11.18%


Lucas De Marchi10.03%11.18%


Andrea Gelmini10.03%11.18%


Total3458100.00%85100.00%


Directory: arch/mips/kernel



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