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/* *  Derived from "arch/i386/kernel/process.c" *    Copyright (C) 1995  Linus Torvalds * *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and *  Paul Mackerras (paulus@cs.anu.edu.au) * *  PowerPC version *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * *  This program is free software; you can redistribute it and/or *  modify it under the terms of the GNU General Public License *  as published by the Free Software Foundation; either version *  2 of the License, or (at your option) any later version. */ #include <linux/errno.h>#include <linux/sched.h>#include <linux/kernel.h>#include <linux/mm.h>#include <linux/smp.h>#include <linux/stddef.h>#include <linux/unistd.h>#include <linux/ptrace.h>#include <linux/slab.h>#include <linux/user.h>#include <linux/elf.h>#include <linux/prctl.h>#include <linux/init_task.h>#include <linux/export.h>#include <linux/kallsyms.h>#include <linux/mqueue.h>#include <linux/hardirq.h>#include <linux/utsname.h>#include <linux/ftrace.h>#include <linux/kernel_stat.h>#include <linux/personality.h>#include <linux/random.h>#include <linux/hw_breakpoint.h>#include <linux/uaccess.h> #include <asm/pgtable.h>#include <asm/io.h>#include <asm/processor.h>#include <asm/mmu.h>#include <asm/prom.h>#include <asm/machdep.h>#include <asm/time.h>#include <asm/runlatch.h>#include <asm/syscalls.h>#include <asm/switch_to.h>#include <asm/tm.h>#include <asm/debug.h>#ifdef CONFIG_PPC64#include <asm/firmware.h>#endif#include <asm/code-patching.h>#include <linux/kprobes.h>#include <linux/kdebug.h> /* Transactional Memory debug */#ifdef TM_DEBUG_SW#define TM_DEBUG(x...) printk(KERN_INFO x)#else#define TM_DEBUG(x...) do { } while(0)#endif extern unsigned long _get_SP(void); #ifdef CONFIG_PPC_TRANSACTIONAL_MEMstatic void check_if_tm_restore_required(struct task_struct *tsk){	/*	 * If we are saving the current thread's registers, and the	 * thread is in a transactional state, set the TIF_RESTORE_TM	 * bit so that we know to restore the registers before	 * returning to userspace.	 */	if (tsk == current && tsk->thread.regs &&	    MSR_TM_ACTIVE(tsk->thread.regs->msr) &&	    !test_thread_flag(TIF_RESTORE_TM)) {		tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;		set_thread_flag(TIF_RESTORE_TM);	}}#elsestatic inline void check_if_tm_restore_required(struct task_struct *tsk) { }#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ bool strict_msr_control;EXPORT_SYMBOL(strict_msr_control); static int __init enable_strict_msr_control(char *str){	strict_msr_control = true;	pr_info("Enabling strict facility control\n"); 	return 0;}early_param("ppc_strict_facility_enable", enable_strict_msr_control); void msr_check_and_set(unsigned long bits){	unsigned long oldmsr = mfmsr();	unsigned long newmsr; 	newmsr = oldmsr | bits; #ifdef CONFIG_VSX	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))		newmsr |= MSR_VSX;#endif 	if (oldmsr != newmsr)		mtmsr_isync(newmsr);} void __msr_check_and_clear(unsigned long bits){	unsigned long oldmsr = mfmsr();	unsigned long newmsr; 	newmsr = oldmsr & ~bits; #ifdef CONFIG_VSX	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))		newmsr &= ~MSR_VSX;#endif 	if (oldmsr != newmsr)		mtmsr_isync(newmsr);}EXPORT_SYMBOL(__msr_check_and_clear); #ifdef CONFIG_PPC_FPUvoid giveup_fpu(struct task_struct *tsk){	check_if_tm_restore_required(tsk); 	msr_check_and_set(MSR_FP);	__giveup_fpu(tsk);	msr_check_and_clear(MSR_FP);}EXPORT_SYMBOL(giveup_fpu); /* * Make sure the floating-point register state in the * the thread_struct is up to date for task tsk. */void flush_fp_to_thread(struct task_struct *tsk){	if (tsk->thread.regs) {		/*		 * We need to disable preemption here because if we didn't,		 * another process could get scheduled after the regs->msr		 * test but before we have finished saving the FP registers		 * to the thread_struct.  That process could take over the		 * FPU, and then when we get scheduled again we would store		 * bogus values for the remaining FP registers.		 */		preempt_disable();		if (tsk->thread.regs->msr & MSR_FP) {			/*			 * This should only ever be called for current or			 * for a stopped child process.  Since we save away			 * the FP register state on context switch,			 * there is something wrong if a stopped child appears			 * to still have its FP state in the CPU registers.			 */			BUG_ON(tsk != current);			giveup_fpu(tsk);		}		preempt_enable();	}}EXPORT_SYMBOL_GPL(flush_fp_to_thread); void enable_kernel_fp(void){	WARN_ON(preemptible()); 	msr_check_and_set(MSR_FP); 	if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {		check_if_tm_restore_required(current);		__giveup_fpu(current);	}}EXPORT_SYMBOL(enable_kernel_fp);#endif /* CONFIG_PPC_FPU */ #ifdef CONFIG_ALTIVECvoid giveup_altivec(struct task_struct *tsk){	check_if_tm_restore_required(tsk); 	msr_check_and_set(MSR_VEC);	__giveup_altivec(tsk);	msr_check_and_clear(MSR_VEC);}EXPORT_SYMBOL(giveup_altivec); void enable_kernel_altivec(void){	WARN_ON(preemptible()); 	msr_check_and_set(MSR_VEC); 	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {		check_if_tm_restore_required(current);		__giveup_altivec(current);	}}EXPORT_SYMBOL(enable_kernel_altivec); /* * Make sure the VMX/Altivec register state in the * the thread_struct is up to date for task tsk. */void flush_altivec_to_thread(struct task_struct *tsk){	if (tsk->thread.regs) {		preempt_disable();		if (tsk->thread.regs->msr & MSR_VEC) {			BUG_ON(tsk != current);			giveup_altivec(tsk);		}		preempt_enable();	}}EXPORT_SYMBOL_GPL(flush_altivec_to_thread);#endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_VSXvoid giveup_vsx(struct task_struct *tsk){	check_if_tm_restore_required(tsk); 	msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);	if (tsk->thread.regs->msr & MSR_FP)		__giveup_fpu(tsk);	if (tsk->thread.regs->msr & MSR_VEC)		__giveup_altivec(tsk);	__giveup_vsx(tsk);	msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);}EXPORT_SYMBOL(giveup_vsx); void enable_kernel_vsx(void){	WARN_ON(preemptible()); 	msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX); 	if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) {		check_if_tm_restore_required(current);		if (current->thread.regs->msr & MSR_FP)			__giveup_fpu(current);		if (current->thread.regs->msr & MSR_VEC)			__giveup_altivec(current);		__giveup_vsx(current);	}}EXPORT_SYMBOL(enable_kernel_vsx); void flush_vsx_to_thread(struct task_struct *tsk){	if (tsk->thread.regs) {		preempt_disable();		if (tsk->thread.regs->msr & MSR_VSX) {			BUG_ON(tsk != current);			giveup_vsx(tsk);		}		preempt_enable();	}}EXPORT_SYMBOL_GPL(flush_vsx_to_thread);#endif /* CONFIG_VSX */ #ifdef CONFIG_SPEvoid giveup_spe(struct task_struct *tsk){	check_if_tm_restore_required(tsk); 	msr_check_and_set(MSR_SPE);	__giveup_spe(tsk);	msr_check_and_clear(MSR_SPE);}EXPORT_SYMBOL(giveup_spe); void enable_kernel_spe(void){	WARN_ON(preemptible()); 	msr_check_and_set(MSR_SPE); 	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {		check_if_tm_restore_required(current);		__giveup_spe(current);	}}EXPORT_SYMBOL(enable_kernel_spe); void flush_spe_to_thread(struct task_struct *tsk){	if (tsk->thread.regs) {		preempt_disable();		if (tsk->thread.regs->msr & MSR_SPE) {			BUG_ON(tsk != current);			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);			giveup_spe(tsk);		}		preempt_enable();	}}#endif /* CONFIG_SPE */ static unsigned long msr_all_available; static int __init init_msr_all_available(void){#ifdef CONFIG_PPC_FPU	msr_all_available |= MSR_FP;#endif#ifdef CONFIG_ALTIVEC	if (cpu_has_feature(CPU_FTR_ALTIVEC))		msr_all_available |= MSR_VEC;#endif#ifdef CONFIG_VSX	if (cpu_has_feature(CPU_FTR_VSX))		msr_all_available |= MSR_VSX;#endif#ifdef CONFIG_SPE	if (cpu_has_feature(CPU_FTR_SPE))		msr_all_available |= MSR_SPE;#endif 	return 0;}early_initcall(init_msr_all_available); void giveup_all(struct task_struct *tsk){	unsigned long usermsr; 	if (!tsk->thread.regs)		return; 	usermsr = tsk->thread.regs->msr; 	if ((usermsr & msr_all_available) == 0)		return; 	msr_check_and_set(msr_all_available); #ifdef CONFIG_PPC_FPU	if (usermsr & MSR_FP)		__giveup_fpu(tsk);#endif#ifdef CONFIG_ALTIVEC	if (usermsr & MSR_VEC)		__giveup_altivec(tsk);#endif#ifdef CONFIG_VSX	if (usermsr & MSR_VSX)		__giveup_vsx(tsk);#endif#ifdef CONFIG_SPE	if (usermsr & MSR_SPE)		__giveup_spe(tsk);#endif 	msr_check_and_clear(msr_all_available);}EXPORT_SYMBOL(giveup_all); void flush_all_to_thread(struct task_struct *tsk){	if (tsk->thread.regs) {		preempt_disable();		BUG_ON(tsk != current);		giveup_all(tsk); #ifdef CONFIG_SPE		if (tsk->thread.regs->msr & MSR_SPE)			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);#endif 		preempt_enable();	}}EXPORT_SYMBOL(flush_all_to_thread); #ifdef CONFIG_PPC_ADV_DEBUG_REGSvoid do_send_trap(struct pt_regs *regs, unsigned long address,		  unsigned long error_code, int signal_code, int breakpt){	siginfo_t info; 	current->thread.trap_nr = signal_code;	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,			11, SIGSEGV) == NOTIFY_STOP)		return; 	/* Deliver the signal to userspace */	info.si_signo = SIGTRAP;	info.si_errno = breakpt;	/* breakpoint or watchpoint id */	info.si_code = signal_code;	info.si_addr = (void __user *)address;	force_sig_info(SIGTRAP, &info, current);}#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */void do_break (struct pt_regs *regs, unsigned long address,		    unsigned long error_code){	siginfo_t info; 	current->thread.trap_nr = TRAP_HWBKPT;	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,			11, SIGSEGV) == NOTIFY_STOP)		return; 	if (debugger_break_match(regs))		return; 	/* Clear the breakpoint */	hw_breakpoint_disable(); 	/* Deliver the signal to userspace */	info.si_signo = SIGTRAP;	info.si_errno = 0;	info.si_code = TRAP_HWBKPT;	info.si_addr = (void __user *)address;	force_sig_info(SIGTRAP, &info, current);}#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */ static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk); #ifdef CONFIG_PPC_ADV_DEBUG_REGS/* * Set the debug registers back to their default "safe" values. */static void set_debug_reg_defaults(struct thread_struct *thread){	thread->debug.iac1 = thread->debug.iac2 = 0;#if CONFIG_PPC_ADV_DEBUG_IACS > 2	thread->debug.iac3 = thread->debug.iac4 = 0;#endif	thread->debug.dac1 = thread->debug.dac2 = 0;#if CONFIG_PPC_ADV_DEBUG_DVCS > 0	thread->debug.dvc1 = thread->debug.dvc2 = 0;#endif	thread->debug.dbcr0 = 0;#ifdef CONFIG_BOOKE	/*	 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)	 */	thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |			DBCR1_IAC3US | DBCR1_IAC4US;	/*	 * Force Data Address Compare User/Supervisor bits to be User-only	 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.	 */	thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;#else	thread->debug.dbcr1 = 0;#endif} static void prime_debug_regs(struct debug_reg *debug){	/*	 * We could have inherited MSR_DE from userspace, since	 * it doesn't get cleared on exception entry.  Make sure	 * MSR_DE is clear before we enable any debug events.	 */	mtmsr(mfmsr() & ~MSR_DE); 	mtspr(SPRN_IAC1, debug->iac1);	mtspr(SPRN_IAC2, debug->iac2);#if CONFIG_PPC_ADV_DEBUG_IACS > 2	mtspr(SPRN_IAC3, debug->iac3);	mtspr(SPRN_IAC4, debug->iac4);#endif	mtspr(SPRN_DAC1, debug->dac1);	mtspr(SPRN_DAC2, debug->dac2);#if CONFIG_PPC_ADV_DEBUG_DVCS > 0	mtspr(SPRN_DVC1, debug->dvc1);	mtspr(SPRN_DVC2, debug->dvc2);#endif	mtspr(SPRN_DBCR0, debug->dbcr0);	mtspr(SPRN_DBCR1, debug->dbcr1);#ifdef CONFIG_BOOKE	mtspr(SPRN_DBCR2, debug->dbcr2);#endif}/* * Unless neither the old or new thread are making use of the * debug registers, set the debug registers from the values

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