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Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 2190 |
1 files changed, 2190 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c new file mode 100644 index 000000000..56c33285b --- /dev/null +++ b/arch/powerpc/kernel/process.c @@ -0,0 +1,2190 @@ +/* + * 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/sched/debug.h> +#include <linux/sched/task.h> +#include <linux/sched/task_stack.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 <linux/elf-randomize.h> +#include <linux/pkeys.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> +#include <asm/hw_irq.h> +#endif +#include <asm/code-patching.h> +#include <asm/exec.h> +#include <asm/livepatch.h> +#include <asm/cpu_has_feature.h> +#include <asm/asm-prototypes.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_MEM +/* + * Are we running in "Suspend disabled" mode? If so we have to block any + * sigreturn that would get us into suspended state, and we also warn in some + * other paths that we should never reach with suspend disabled. + */ +bool tm_suspend_disabled __ro_after_init = false; + +static 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); + } +} + +#else +static 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); + +unsigned long 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); + + return newmsr; +} +EXPORT_SYMBOL_GPL(msr_check_and_set); + +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_FPU +static void __giveup_fpu(struct task_struct *tsk) +{ + unsigned long msr; + + save_fpu(tsk); + msr = tsk->thread.regs->msr; + msr &= ~(MSR_FP|MSR_FE0|MSR_FE1); +#ifdef CONFIG_VSX + if (cpu_has_feature(CPU_FTR_VSX)) + msr &= ~MSR_VSX; +#endif + tsk->thread.regs->msr = msr; +} + +void 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) +{ + unsigned long cpumsr; + + WARN_ON(preemptible()); + + cpumsr = msr_check_and_set(MSR_FP); + + if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) { + check_if_tm_restore_required(current); + /* + * If a thread has already been reclaimed then the + * checkpointed registers are on the CPU but have definitely + * been saved by the reclaim code. Don't need to and *cannot* + * giveup as this would save to the 'live' structure not the + * checkpointed structure. + */ + if (!MSR_TM_ACTIVE(cpumsr) && + MSR_TM_ACTIVE(current->thread.regs->msr)) + return; + __giveup_fpu(current); + } +} +EXPORT_SYMBOL(enable_kernel_fp); + +static int restore_fp(struct task_struct *tsk) +{ + if (tsk->thread.load_fp) { + load_fp_state(¤t->thread.fp_state); + current->thread.load_fp++; + return 1; + } + return 0; +} +#else +static int restore_fp(struct task_struct *tsk) { return 0; } +#endif /* CONFIG_PPC_FPU */ + +#ifdef CONFIG_ALTIVEC +#define loadvec(thr) ((thr).load_vec) + +static void __giveup_altivec(struct task_struct *tsk) +{ + unsigned long msr; + + save_altivec(tsk); + msr = tsk->thread.regs->msr; + msr &= ~MSR_VEC; +#ifdef CONFIG_VSX + if (cpu_has_feature(CPU_FTR_VSX)) + msr &= ~MSR_VSX; +#endif + tsk->thread.regs->msr = msr; +} + +void 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) +{ + unsigned long cpumsr; + + WARN_ON(preemptible()); + + cpumsr = msr_check_and_set(MSR_VEC); + + if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) { + check_if_tm_restore_required(current); + /* + * If a thread has already been reclaimed then the + * checkpointed registers are on the CPU but have definitely + * been saved by the reclaim code. Don't need to and *cannot* + * giveup as this would save to the 'live' structure not the + * checkpointed structure. + */ + if (!MSR_TM_ACTIVE(cpumsr) && + MSR_TM_ACTIVE(current->thread.regs->msr)) + return; + __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); + +static int restore_altivec(struct task_struct *tsk) +{ + if (cpu_has_feature(CPU_FTR_ALTIVEC) && (tsk->thread.load_vec)) { + load_vr_state(&tsk->thread.vr_state); + tsk->thread.used_vr = 1; + tsk->thread.load_vec++; + + return 1; + } + return 0; +} +#else +#define loadvec(thr) 0 +static inline int restore_altivec(struct task_struct *tsk) { return 0; } +#endif /* CONFIG_ALTIVEC */ + +#ifdef CONFIG_VSX +static void __giveup_vsx(struct task_struct *tsk) +{ + unsigned long msr = tsk->thread.regs->msr; + + /* + * We should never be ssetting MSR_VSX without also setting + * MSR_FP and MSR_VEC + */ + WARN_ON((msr & MSR_VSX) && !((msr & MSR_FP) && (msr & MSR_VEC))); + + /* __giveup_fpu will clear MSR_VSX */ + if (msr & MSR_FP) + __giveup_fpu(tsk); + if (msr & MSR_VEC) + __giveup_altivec(tsk); +} + +static void giveup_vsx(struct task_struct *tsk) +{ + check_if_tm_restore_required(tsk); + + msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX); + __giveup_vsx(tsk); + msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX); +} + +void enable_kernel_vsx(void) +{ + unsigned long cpumsr; + + WARN_ON(preemptible()); + + cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX); + + if (current->thread.regs && + (current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP))) { + check_if_tm_restore_required(current); + /* + * If a thread has already been reclaimed then the + * checkpointed registers are on the CPU but have definitely + * been saved by the reclaim code. Don't need to and *cannot* + * giveup as this would save to the 'live' structure not the + * checkpointed structure. + */ + if (!MSR_TM_ACTIVE(cpumsr) && + MSR_TM_ACTIVE(current->thread.regs->msr)) + return; + __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|MSR_VEC|MSR_FP)) { + BUG_ON(tsk != current); + giveup_vsx(tsk); + } + preempt_enable(); + } +} +EXPORT_SYMBOL_GPL(flush_vsx_to_thread); + +static int restore_vsx(struct task_struct *tsk) +{ + if (cpu_has_feature(CPU_FTR_VSX)) { + tsk->thread.used_vsr = 1; + return 1; + } + + return 0; +} +#else +static inline int restore_vsx(struct task_struct *tsk) { return 0; } +#endif /* CONFIG_VSX */ + +#ifdef CONFIG_SPE +void 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; + + check_if_tm_restore_required(tsk); + + usermsr = tsk->thread.regs->msr; + + if ((usermsr & msr_all_available) == 0) + return; + + msr_check_and_set(msr_all_available); + + WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC))); + +#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_SPE + if (usermsr & MSR_SPE) + __giveup_spe(tsk); +#endif + + msr_check_and_clear(msr_all_available); +} +EXPORT_SYMBOL(giveup_all); + +void restore_math(struct pt_regs *regs) +{ + unsigned long msr; + + if (!MSR_TM_ACTIVE(regs->msr) && + !current->thread.load_fp && !loadvec(current->thread)) + return; + + msr = regs->msr; + msr_check_and_set(msr_all_available); + + /* + * Only reload if the bit is not set in the user MSR, the bit BEING set + * indicates that the registers are hot + */ + if ((!(msr & MSR_FP)) && restore_fp(current)) + msr |= MSR_FP | current->thread.fpexc_mode; + + if ((!(msr & MSR_VEC)) && restore_altivec(current)) + msr |= MSR_VEC; + + if ((msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC) && + restore_vsx(current)) { + msr |= MSR_VSX; + } + + msr_check_and_clear(msr_all_available); + + regs->msr = msr; +} + +static void save_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); + + WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC))); + + if (usermsr & MSR_FP) + save_fpu(tsk); + + if (usermsr & MSR_VEC) + save_altivec(tsk); + + if (usermsr & MSR_SPE) + __giveup_spe(tsk); + + msr_check_and_clear(msr_all_available); + thread_pkey_regs_save(&tsk->thread); +} + +void flush_all_to_thread(struct task_struct *tsk) +{ + if (tsk->thread.regs) { + preempt_disable(); + BUG_ON(tsk != current); +#ifdef CONFIG_SPE + if (tsk->thread.regs->msr & MSR_SPE) + tsk->thread.spefscr = mfspr(SPRN_SPEFSCR); +#endif + save_all(tsk); + + preempt_enable(); + } +} +EXPORT_SYMBOL(flush_all_to_thread); + +#ifdef CONFIG_PPC_ADV_DEBUG_REGS +void do_send_trap(struct pt_regs *regs, unsigned long address, + unsigned long error_code, int breakpt) +{ + current->thread.trap_nr = TRAP_HWBKPT; + if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, + 11, SIGSEGV) == NOTIFY_STOP) + return; + + /* Deliver the signal to userspace */ + force_sig_ptrace_errno_trap(breakpt, /* breakpoint or watchpoint id */ + (void __user *)address); +} +#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 */ + clear_siginfo(&info); + 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 + * stored in the new thread. + */ +void switch_booke_debug_regs(struct debug_reg *new_debug) +{ + if ((current->thread.debug.dbcr0 & DBCR0_IDM) + || (new_debug->dbcr0 & DBCR0_IDM)) + prime_debug_regs(new_debug); +} +EXPORT_SYMBOL_GPL(switch_booke_debug_regs); +#else /* !CONFIG_PPC_ADV_DEBUG_REGS */ +#ifndef CONFIG_HAVE_HW_BREAKPOINT +static void set_breakpoint(struct arch_hw_breakpoint *brk) +{ + preempt_disable(); + __set_breakpoint(brk); + preempt_enable(); +} + +static void set_debug_reg_defaults(struct thread_struct *thread) +{ + thread->hw_brk.address = 0; + thread->hw_brk.type = 0; + if (ppc_breakpoint_available()) + set_breakpoint(&thread->hw_brk); +} +#endif /* !CONFIG_HAVE_HW_BREAKPOINT */ +#endif /* CONFIG_PPC_ADV_DEBUG_REGS */ + +#ifdef CONFIG_PPC_ADV_DEBUG_REGS +static inline int __set_dabr(unsigned long dabr, unsigned long dabrx) +{ + mtspr(SPRN_DAC1, dabr); +#ifdef CONFIG_PPC_47x + isync(); +#endif + return 0; +} +#elif defined(CONFIG_PPC_BOOK3S) +static inline int __set_dabr(unsigned long dabr, unsigned long dabrx) +{ + mtspr(SPRN_DABR, dabr); + if (cpu_has_feature(CPU_FTR_DABRX)) + mtspr(SPRN_DABRX, dabrx); + return 0; +} +#elif defined(CONFIG_PPC_8xx) +static inline int __set_dabr(unsigned long dabr, unsigned long dabrx) +{ + unsigned long addr = dabr & ~HW_BRK_TYPE_DABR; + unsigned long lctrl1 = 0x90000000; /* compare type: equal on E & F */ + unsigned long lctrl2 = 0x8e000002; /* watchpoint 1 on cmp E | F */ + + if ((dabr & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_READ) + lctrl1 |= 0xa0000; + else if ((dabr & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_WRITE) + lctrl1 |= 0xf0000; + else if ((dabr & HW_BRK_TYPE_RDWR) == 0) + lctrl2 = 0; + + mtspr(SPRN_LCTRL2, 0); + mtspr(SPRN_CMPE, addr); + mtspr(SPRN_CMPF, addr + 4); + mtspr(SPRN_LCTRL1, lctrl1); + mtspr(SPRN_LCTRL2, lctrl2); + + return 0; +} +#else +static inline int __set_dabr(unsigned long dabr, unsigned long dabrx) +{ + return -EINVAL; +} +#endif + +static inline int set_dabr(struct arch_hw_breakpoint *brk) +{ + unsigned long dabr, dabrx; + + dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR); + dabrx = ((brk->type >> 3) & 0x7); + + if (ppc_md.set_dabr) + return ppc_md.set_dabr(dabr, dabrx); + + return __set_dabr(dabr, dabrx); +} + +static inline int set_dawr(struct arch_hw_breakpoint *brk) +{ + unsigned long dawr, dawrx, mrd; + + dawr = brk->address; + + dawrx = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)) \ + << (63 - 58); //* read/write bits */ + dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \ + << (63 - 59); //* translate */ + dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \ + >> 3; //* PRIM bits */ + /* dawr length is stored in field MDR bits 48:53. Matches range in + doublewords (64 bits) baised by -1 eg. 0b000000=1DW and + 0b111111=64DW. + brk->len is in bytes. + This aligns up to double word size, shifts and does the bias. + */ + mrd = ((brk->len + 7) >> 3) - 1; + dawrx |= (mrd & 0x3f) << (63 - 53); + + if (ppc_md.set_dawr) + return ppc_md.set_dawr(dawr, dawrx); + mtspr(SPRN_DAWR, dawr); + mtspr(SPRN_DAWRX, dawrx); + return 0; +} + +void __set_breakpoint(struct arch_hw_breakpoint *brk) +{ + memcpy(this_cpu_ptr(¤t_brk), brk, sizeof(*brk)); + + if (cpu_has_feature(CPU_FTR_DAWR)) + // Power8 or later + set_dawr(brk); + else if (!cpu_has_feature(CPU_FTR_ARCH_207S)) + // Power7 or earlier + set_dabr(brk); + else + // Shouldn't happen due to higher level checks + WARN_ON_ONCE(1); +} + +/* Check if we have DAWR or DABR hardware */ +bool ppc_breakpoint_available(void) +{ + if (cpu_has_feature(CPU_FTR_DAWR)) + return true; /* POWER8 DAWR */ + if (cpu_has_feature(CPU_FTR_ARCH_207S)) + return false; /* POWER9 with DAWR disabled */ + /* DABR: Everything but POWER8 and POWER9 */ + return true; +} +EXPORT_SYMBOL_GPL(ppc_breakpoint_available); + +static inline bool hw_brk_match(struct arch_hw_breakpoint *a, + struct arch_hw_breakpoint *b) +{ + if (a->address != b->address) + return false; + if (a->type != b->type) + return false; + if (a->len != b->len) + return false; + return true; +} + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + +static inline bool tm_enabled(struct task_struct *tsk) +{ + return tsk && tsk->thread.regs && (tsk->thread.regs->msr & MSR_TM); +} + +static void tm_reclaim_thread(struct thread_struct *thr, uint8_t cause) +{ + /* + * Use the current MSR TM suspended bit to track if we have + * checkpointed state outstanding. + * On signal delivery, we'd normally reclaim the checkpointed + * state to obtain stack pointer (see:get_tm_stackpointer()). + * This will then directly return to userspace without going + * through __switch_to(). However, if the stack frame is bad, + * we need to exit this thread which calls __switch_to() which + * will again attempt to reclaim the already saved tm state. + * Hence we need to check that we've not already reclaimed + * this state. + * We do this using the current MSR, rather tracking it in + * some specific thread_struct bit, as it has the additional + * benefit of checking for a potential TM bad thing exception. + */ + if (!MSR_TM_SUSPENDED(mfmsr())) + return; + + giveup_all(container_of(thr, struct task_struct, thread)); + + tm_reclaim(thr, cause); + + /* + * If we are in a transaction and FP is off then we can't have + * used FP inside that transaction. Hence the checkpointed + * state is the same as the live state. We need to copy the + * live state to the checkpointed state so that when the + * transaction is restored, the checkpointed state is correct + * and the aborted transaction sees the correct state. We use + * ckpt_regs.msr here as that's what tm_reclaim will use to + * determine if it's going to write the checkpointed state or + * not. So either this will write the checkpointed registers, + * or reclaim will. Similarly for VMX. + */ + if ((thr->ckpt_regs.msr & MSR_FP) == 0) + memcpy(&thr->ckfp_state, &thr->fp_state, + sizeof(struct thread_fp_state)); + if ((thr->ckpt_regs.msr & MSR_VEC) == 0) + memcpy(&thr->ckvr_state, &thr->vr_state, + sizeof(struct thread_vr_state)); +} + +void tm_reclaim_current(uint8_t cause) +{ + tm_enable(); + tm_reclaim_thread(¤t->thread, cause); +} + +static inline void tm_reclaim_task(struct task_struct *tsk) +{ + /* We have to work out if we're switching from/to a task that's in the + * middle of a transaction. + * + * In switching we need to maintain a 2nd register state as + * oldtask->thread.ckpt_regs. We tm_reclaim(oldproc); this saves the + * checkpointed (tbegin) state in ckpt_regs, ckfp_state and + * ckvr_state + * + * We also context switch (save) TFHAR/TEXASR/TFIAR in here. + */ + struct thread_struct *thr = &tsk->thread; + + if (!thr->regs) + return; + + if (!MSR_TM_ACTIVE(thr->regs->msr)) + goto out_and_saveregs; + + WARN_ON(tm_suspend_disabled); + + TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, " + "ccr=%lx, msr=%lx, trap=%lx)\n", + tsk->pid, thr->regs->nip, + thr->regs->ccr, thr->regs->msr, + thr->regs->trap); + + tm_reclaim_thread(thr, TM_CAUSE_RESCHED); + + TM_DEBUG("--- tm_reclaim on pid %d complete\n", + tsk->pid); + +out_and_saveregs: + /* Always save the regs here, even if a transaction's not active. + * This context-switches a thread's TM info SPRs. We do it here to + * be consistent with the restore path (in recheckpoint) which + * cannot happen later in _switch(). + */ + tm_save_sprs(thr); +} + +extern void __tm_recheckpoint(struct thread_struct *thread); + +void tm_recheckpoint(struct thread_struct *thread) +{ + unsigned long flags; + + if (!(thread->regs->msr & MSR_TM)) + return; + + /* We really can't be interrupted here as the TEXASR registers can't + * change and later in the trecheckpoint code, we have a userspace R1. + * So let's hard disable over this region. + */ + local_irq_save(flags); + hard_irq_disable(); + + /* The TM SPRs are restored here, so that TEXASR.FS can be set + * before the trecheckpoint and no explosion occurs. + */ + tm_restore_sprs(thread); + + __tm_recheckpoint(thread); + + local_irq_restore(flags); +} + +static inline void tm_recheckpoint_new_task(struct task_struct *new) +{ + if (!cpu_has_feature(CPU_FTR_TM)) + return; + + /* Recheckpoint the registers of the thread we're about to switch to. + * + * If the task was using FP, we non-lazily reload both the original and + * the speculative FP register states. This is because the kernel + * doesn't see if/when a TM rollback occurs, so if we take an FP + * unavailable later, we are unable to determine which set of FP regs + * need to be restored. + */ + if (!tm_enabled(new)) + return; + + if (!MSR_TM_ACTIVE(new->thread.regs->msr)){ + tm_restore_sprs(&new->thread); + return; + } + /* Recheckpoint to restore original checkpointed register state. */ + TM_DEBUG("*** tm_recheckpoint of pid %d (new->msr 0x%lx)\n", + new->pid, new->thread.regs->msr); + + tm_recheckpoint(&new->thread); + + /* + * The checkpointed state has been restored but the live state has + * not, ensure all the math functionality is turned off to trigger + * restore_math() to reload. + */ + new->thread.regs->msr &= ~(MSR_FP | MSR_VEC | MSR_VSX); + + TM_DEBUG("*** tm_recheckpoint of pid %d complete " + "(kernel msr 0x%lx)\n", + new->pid, mfmsr()); +} + +static inline void __switch_to_tm(struct task_struct *prev, + struct task_struct *new) +{ + if (cpu_has_feature(CPU_FTR_TM)) { + if (tm_enabled(prev) || tm_enabled(new)) + tm_enable(); + + if (tm_enabled(prev)) { + prev->thread.load_tm++; + tm_reclaim_task(prev); + if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0) + prev->thread.regs->msr &= ~MSR_TM; + } + + tm_recheckpoint_new_task(new); + } +} + +/* + * This is called if we are on the way out to userspace and the + * TIF_RESTORE_TM flag is set. It checks if we need to reload + * FP and/or vector state and does so if necessary. + * If userspace is inside a transaction (whether active or + * suspended) and FP/VMX/VSX instructions have ever been enabled + * inside that transaction, then we have to keep them enabled + * and keep the FP/VMX/VSX state loaded while ever the transaction + * continues. The reason is that if we didn't, and subsequently + * got a FP/VMX/VSX unavailable interrupt inside a transaction, + * we don't know whether it's the same transaction, and thus we + * don't know which of the checkpointed state and the transactional + * state to use. + */ +void restore_tm_state(struct pt_regs *regs) +{ + unsigned long msr_diff; + + /* + * This is the only moment we should clear TIF_RESTORE_TM as + * it is here that ckpt_regs.msr and pt_regs.msr become the same + * again, anything else could lead to an incorrect ckpt_msr being + * saved and therefore incorrect signal contexts. + */ + clear_thread_flag(TIF_RESTORE_TM); + if (!MSR_TM_ACTIVE(regs->msr)) + return; + + msr_diff = current->thread.ckpt_regs.msr & ~regs->msr; + msr_diff &= MSR_FP | MSR_VEC | MSR_VSX; + + /* Ensure that restore_math() will restore */ + if (msr_diff & MSR_FP) + current->thread.load_fp = 1; +#ifdef CONFIG_ALTIVEC + if (cpu_has_feature(CPU_FTR_ALTIVEC) && msr_diff & MSR_VEC) + current->thread.load_vec = 1; +#endif + restore_math(regs); + + regs->msr |= msr_diff; +} + +#else +#define tm_recheckpoint_new_task(new) +#define __switch_to_tm(prev, new) +#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ + +static inline void save_sprs(struct thread_struct *t) +{ +#ifdef CONFIG_ALTIVEC + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + t->vrsave = mfspr(SPRN_VRSAVE); +#endif +#ifdef CONFIG_PPC_BOOK3S_64 + if (cpu_has_feature(CPU_FTR_DSCR)) + t->dscr = mfspr(SPRN_DSCR); + + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + t->bescr = mfspr(SPRN_BESCR); + t->ebbhr = mfspr(SPRN_EBBHR); + t->ebbrr = mfspr(SPRN_EBBRR); + + t->fscr = mfspr(SPRN_FSCR); + + /* + * Note that the TAR is not available for use in the kernel. + * (To provide this, the TAR should be backed up/restored on + * exception entry/exit instead, and be in pt_regs. FIXME, + * this should be in pt_regs anyway (for debug).) + */ + t->tar = mfspr(SPRN_TAR); + } +#endif + + thread_pkey_regs_save(t); +} + +static inline void restore_sprs(struct thread_struct *old_thread, + struct thread_struct *new_thread) +{ +#ifdef CONFIG_ALTIVEC + if (cpu_has_feature(CPU_FTR_ALTIVEC) && + old_thread->vrsave != new_thread->vrsave) + mtspr(SPRN_VRSAVE, new_thread->vrsave); +#endif +#ifdef CONFIG_PPC_BOOK3S_64 + if (cpu_has_feature(CPU_FTR_DSCR)) { + u64 dscr = get_paca()->dscr_default; + if (new_thread->dscr_inherit) + dscr = new_thread->dscr; + + if (old_thread->dscr != dscr) + mtspr(SPRN_DSCR, dscr); + } + + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + if (old_thread->bescr != new_thread->bescr) + mtspr(SPRN_BESCR, new_thread->bescr); + if (old_thread->ebbhr != new_thread->ebbhr) + mtspr(SPRN_EBBHR, new_thread->ebbhr); + if (old_thread->ebbrr != new_thread->ebbrr) + mtspr(SPRN_EBBRR, new_thread->ebbrr); + + if (old_thread->fscr != new_thread->fscr) + mtspr(SPRN_FSCR, new_thread->fscr); + + if (old_thread->tar != new_thread->tar) + mtspr(SPRN_TAR, new_thread->tar); + } + + if (cpu_has_feature(CPU_FTR_P9_TIDR) && + old_thread->tidr != new_thread->tidr) + mtspr(SPRN_TIDR, new_thread->tidr); +#endif + + thread_pkey_regs_restore(new_thread, old_thread); +} + +#ifdef CONFIG_PPC_BOOK3S_64 +#define CP_SIZE 128 +static const u8 dummy_copy_buffer[CP_SIZE] __attribute__((aligned(CP_SIZE))); +#endif + +struct task_struct *__switch_to(struct task_struct *prev, + struct task_struct *new) +{ + struct thread_struct *new_thread, *old_thread; + struct task_struct *last; +#ifdef CONFIG_PPC_BOOK3S_64 + struct ppc64_tlb_batch *batch; +#endif + + new_thread = &new->thread; + old_thread = ¤t->thread; + + WARN_ON(!irqs_disabled()); + +#ifdef CONFIG_PPC_BOOK3S_64 + batch = this_cpu_ptr(&ppc64_tlb_batch); + if (batch->active) { + current_thread_info()->local_flags |= _TLF_LAZY_MMU; + if (batch->index) + __flush_tlb_pending(batch); + batch->active = 0; + } +#endif /* CONFIG_PPC_BOOK3S_64 */ + +#ifdef CONFIG_PPC_ADV_DEBUG_REGS + switch_booke_debug_regs(&new->thread.debug); +#else +/* + * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would + * schedule DABR + */ +#ifndef CONFIG_HAVE_HW_BREAKPOINT + if (unlikely(!hw_brk_match(this_cpu_ptr(¤t_brk), &new->thread.hw_brk))) + __set_breakpoint(&new->thread.hw_brk); +#endif /* CONFIG_HAVE_HW_BREAKPOINT */ +#endif + + /* + * We need to save SPRs before treclaim/trecheckpoint as these will + * change a number of them. + */ + save_sprs(&prev->thread); + + /* Save FPU, Altivec, VSX and SPE state */ + giveup_all(prev); + + __switch_to_tm(prev, new); + + if (!radix_enabled()) { + /* + * We can't take a PMU exception inside _switch() since there + * is a window where the kernel stack SLB and the kernel stack + * are out of sync. Hard disable here. + */ + hard_irq_disable(); + } + + /* + * Call restore_sprs() before calling _switch(). If we move it after + * _switch() then we miss out on calling it for new tasks. The reason + * for this is we manually create a stack frame for new tasks that + * directly returns through ret_from_fork() or + * ret_from_kernel_thread(). See copy_thread() for details. + */ + restore_sprs(old_thread, new_thread); + + last = _switch(old_thread, new_thread); + +#ifdef CONFIG_PPC_BOOK3S_64 + if (current_thread_info()->local_flags & _TLF_LAZY_MMU) { + current_thread_info()->local_flags &= ~_TLF_LAZY_MMU; + batch = this_cpu_ptr(&ppc64_tlb_batch); + batch->active = 1; + } + + if (current_thread_info()->task->thread.regs) { + restore_math(current_thread_info()->task->thread.regs); + + /* + * The copy-paste buffer can only store into foreign real + * addresses, so unprivileged processes can not see the + * data or use it in any way unless they have foreign real + * mappings. If the new process has the foreign real address + * mappings, we must issue a cp_abort to clear any state and + * prevent snooping, corruption or a covert channel. + */ + if (current_thread_info()->task->thread.used_vas) + asm volatile(PPC_CP_ABORT); + } +#endif /* CONFIG_PPC_BOOK3S_64 */ + + return last; +} + +static int instructions_to_print = 16; + +static void show_instructions(struct pt_regs *regs) +{ + int i; + unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * + sizeof(int)); + + printk("Instruction dump:"); + + for (i = 0; i < instructions_to_print; i++) { + int instr; + + if (!(i % 8)) + pr_cont("\n"); + +#if !defined(CONFIG_BOOKE) + /* If executing with the IMMU off, adjust pc rather + * than print XXXXXXXX. + */ + if (!(regs->msr & MSR_IR)) + pc = (unsigned long)phys_to_virt(pc); +#endif + + if (!__kernel_text_address(pc) || + probe_kernel_address((unsigned int __user *)pc, instr)) { + pr_cont("XXXXXXXX "); + } else { + if (regs->nip == pc) + pr_cont("<%08x> ", instr); + else + pr_cont("%08x ", instr); + } + + pc += sizeof(int); + } + + pr_cont("\n"); +} + +void show_user_instructions(struct pt_regs *regs) +{ + unsigned long pc; + int i; + + pc = regs->nip - (instructions_to_print * 3 / 4 * sizeof(int)); + + /* + * Make sure the NIP points at userspace, not kernel text/data or + * elsewhere. + */ + if (!__access_ok(pc, instructions_to_print * sizeof(int), USER_DS)) { + pr_info("%s[%d]: Bad NIP, not dumping instructions.\n", + current->comm, current->pid); + return; + } + + pr_info("%s[%d]: code: ", current->comm, current->pid); + + for (i = 0; i < instructions_to_print; i++) { + int instr; + + if (!(i % 8) && (i > 0)) { + pr_cont("\n"); + pr_info("%s[%d]: code: ", current->comm, current->pid); + } + + if (probe_kernel_address((unsigned int __user *)pc, instr)) { + pr_cont("XXXXXXXX "); + } else { + if (regs->nip == pc) + pr_cont("<%08x> ", instr); + else + pr_cont("%08x ", instr); + } + + pc += sizeof(int); + } + + pr_cont("\n"); +} + +struct regbit { + unsigned long bit; + const char *name; +}; + +static struct regbit msr_bits[] = { +#if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE) + {MSR_SF, "SF"}, + {MSR_HV, "HV"}, +#endif + {MSR_VEC, "VEC"}, + {MSR_VSX, "VSX"}, +#ifdef CONFIG_BOOKE + {MSR_CE, "CE"}, +#endif + {MSR_EE, "EE"}, + {MSR_PR, "PR"}, + {MSR_FP, "FP"}, + {MSR_ME, "ME"}, +#ifdef CONFIG_BOOKE + {MSR_DE, "DE"}, +#else + {MSR_SE, "SE"}, + {MSR_BE, "BE"}, +#endif + {MSR_IR, "IR"}, + {MSR_DR, "DR"}, + {MSR_PMM, "PMM"}, +#ifndef CONFIG_BOOKE + {MSR_RI, "RI"}, + {MSR_LE, "LE"}, +#endif + {0, NULL} +}; + +static void print_bits(unsigned long val, struct regbit *bits, const char *sep) +{ + const char *s = ""; + + for (; bits->bit; ++bits) + if (val & bits->bit) { + pr_cont("%s%s", s, bits->name); + s = sep; + } +} + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +static struct regbit msr_tm_bits[] = { + {MSR_TS_T, "T"}, + {MSR_TS_S, "S"}, + {MSR_TM, "E"}, + {0, NULL} +}; + +static void print_tm_bits(unsigned long val) +{ +/* + * This only prints something if at least one of the TM bit is set. + * Inside the TM[], the output means: + * E: Enabled (bit 32) + * S: Suspended (bit 33) + * T: Transactional (bit 34) + */ + if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) { + pr_cont(",TM["); + print_bits(val, msr_tm_bits, ""); + pr_cont("]"); + } +} +#else +static void print_tm_bits(unsigned long val) {} +#endif + +static void print_msr_bits(unsigned long val) +{ + pr_cont("<"); + print_bits(val, msr_bits, ","); + print_tm_bits(val); + pr_cont(">"); +} + +#ifdef CONFIG_PPC64 +#define REG "%016lx" +#define REGS_PER_LINE 4 +#define LAST_VOLATILE 13 +#else +#define REG "%08lx" +#define REGS_PER_LINE 8 +#define LAST_VOLATILE 12 +#endif + +void show_regs(struct pt_regs * regs) +{ + int i, trap; + + show_regs_print_info(KERN_DEFAULT); + + printk("NIP: "REG" LR: "REG" CTR: "REG"\n", + regs->nip, regs->link, regs->ctr); + printk("REGS: %px TRAP: %04lx %s (%s)\n", + regs, regs->trap, print_tainted(), init_utsname()->release); + printk("MSR: "REG" ", regs->msr); + print_msr_bits(regs->msr); + pr_cont(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer); + trap = TRAP(regs); + if ((TRAP(regs) != 0xc00) && cpu_has_feature(CPU_FTR_CFAR)) + pr_cont("CFAR: "REG" ", regs->orig_gpr3); + if (trap == 0x200 || trap == 0x300 || trap == 0x600) +#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) + pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr); +#else + pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr); +#endif +#ifdef CONFIG_PPC64 + pr_cont("IRQMASK: %lx ", regs->softe); +#endif +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + if (MSR_TM_ACTIVE(regs->msr)) + pr_cont("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch); +#endif + + for (i = 0; i < 32; i++) { + if ((i % REGS_PER_LINE) == 0) + pr_cont("\nGPR%02d: ", i); + pr_cont(REG " ", regs->gpr[i]); + if (i == LAST_VOLATILE && !FULL_REGS(regs)) + break; + } + pr_cont("\n"); +#ifdef CONFIG_KALLSYMS + /* + * Lookup NIP late so we have the best change of getting the + * above info out without failing + */ + printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip); + printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link); +#endif + show_stack(current, (unsigned long *) regs->gpr[1]); + if (!user_mode(regs)) + show_instructions(regs); +} + +void flush_thread(void) +{ +#ifdef CONFIG_HAVE_HW_BREAKPOINT + flush_ptrace_hw_breakpoint(current); +#else /* CONFIG_HAVE_HW_BREAKPOINT */ + set_debug_reg_defaults(¤t->thread); +#endif /* CONFIG_HAVE_HW_BREAKPOINT */ +} + +int set_thread_uses_vas(void) +{ +#ifdef CONFIG_PPC_BOOK3S_64 + if (!cpu_has_feature(CPU_FTR_ARCH_300)) + return -EINVAL; + + current->thread.used_vas = 1; + + /* + * Even a process that has no foreign real address mapping can use + * an unpaired COPY instruction (to no real effect). Issue CP_ABORT + * to clear any pending COPY and prevent a covert channel. + * + * __switch_to() will issue CP_ABORT on future context switches. + */ + asm volatile(PPC_CP_ABORT); + +#endif /* CONFIG_PPC_BOOK3S_64 */ + return 0; +} + +#ifdef CONFIG_PPC64 +/** + * Assign a TIDR (thread ID) for task @t and set it in the thread + * structure. For now, we only support setting TIDR for 'current' task. + * + * Since the TID value is a truncated form of it PID, it is possible + * (but unlikely) for 2 threads to have the same TID. In the unlikely event + * that 2 threads share the same TID and are waiting, one of the following + * cases will happen: + * + * 1. The correct thread is running, the wrong thread is not + * In this situation, the correct thread is woken and proceeds to pass it's + * condition check. + * + * 2. Neither threads are running + * In this situation, neither thread will be woken. When scheduled, the waiting + * threads will execute either a wait, which will return immediately, followed + * by a condition check, which will pass for the correct thread and fail + * for the wrong thread, or they will execute the condition check immediately. + * + * 3. The wrong thread is running, the correct thread is not + * The wrong thread will be woken, but will fail it's condition check and + * re-execute wait. The correct thread, when scheduled, will execute either + * it's condition check (which will pass), or wait, which returns immediately + * when called the first time after the thread is scheduled, followed by it's + * condition check (which will pass). + * + * 4. Both threads are running + * Both threads will be woken. The wrong thread will fail it's condition check + * and execute another wait, while the correct thread will pass it's condition + * check. + * + * @t: the task to set the thread ID for + */ +int set_thread_tidr(struct task_struct *t) +{ + if (!cpu_has_feature(CPU_FTR_P9_TIDR)) + return -EINVAL; + + if (t != current) + return -EINVAL; + + if (t->thread.tidr) + return 0; + + t->thread.tidr = (u16)task_pid_nr(t); + mtspr(SPRN_TIDR, t->thread.tidr); + + return 0; +} +EXPORT_SYMBOL_GPL(set_thread_tidr); + +#endif /* CONFIG_PPC64 */ + +void +release_thread(struct task_struct *t) +{ +} + +/* + * this gets called so that we can store coprocessor state into memory and + * copy the current task into the new thread. + */ +int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) +{ + flush_all_to_thread(src); + /* + * Flush TM state out so we can copy it. __switch_to_tm() does this + * flush but it removes the checkpointed state from the current CPU and + * transitions the CPU out of TM mode. Hence we need to call + * tm_recheckpoint_new_task() (on the same task) to restore the + * checkpointed state back and the TM mode. + * + * Can't pass dst because it isn't ready. Doesn't matter, passing + * dst is only important for __switch_to() + */ + __switch_to_tm(src, src); + + *dst = *src; + + clear_task_ebb(dst); + + return 0; +} + +static void setup_ksp_vsid(struct task_struct *p, unsigned long sp) +{ +#ifdef CONFIG_PPC_BOOK3S_64 + unsigned long sp_vsid; + unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; + + if (radix_enabled()) + return; + + if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) + sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T) + << SLB_VSID_SHIFT_1T; + else + sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M) + << SLB_VSID_SHIFT; + sp_vsid |= SLB_VSID_KERNEL | llp; + p->thread.ksp_vsid = sp_vsid; +#endif +} + +/* + * Copy a thread.. + */ + +/* + * Copy architecture-specific thread state + */ +int copy_thread(unsigned long clone_flags, unsigned long usp, + unsigned long kthread_arg, struct task_struct *p) +{ + struct pt_regs *childregs, *kregs; + extern void ret_from_fork(void); + extern void ret_from_kernel_thread(void); + void (*f)(void); + unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; + struct thread_info *ti = task_thread_info(p); + + klp_init_thread_info(ti); + + /* Copy registers */ + sp -= sizeof(struct pt_regs); + childregs = (struct pt_regs *) sp; + if (unlikely(p->flags & PF_KTHREAD)) { + /* kernel thread */ + memset(childregs, 0, sizeof(struct pt_regs)); + childregs->gpr[1] = sp + sizeof(struct pt_regs); + /* function */ + if (usp) + childregs->gpr[14] = ppc_function_entry((void *)usp); +#ifdef CONFIG_PPC64 + clear_tsk_thread_flag(p, TIF_32BIT); + childregs->softe = IRQS_ENABLED; +#endif + childregs->gpr[15] = kthread_arg; + p->thread.regs = NULL; /* no user register state */ + ti->flags |= _TIF_RESTOREALL; + f = ret_from_kernel_thread; + } else { + /* user thread */ + struct pt_regs *regs = current_pt_regs(); + CHECK_FULL_REGS(regs); + *childregs = *regs; + if (usp) + childregs->gpr[1] = usp; + p->thread.regs = childregs; + childregs->gpr[3] = 0; /* Result from fork() */ + if (clone_flags & CLONE_SETTLS) { +#ifdef CONFIG_PPC64 + if (!is_32bit_task()) + childregs->gpr[13] = childregs->gpr[6]; + else +#endif + childregs->gpr[2] = childregs->gpr[6]; + } + + f = ret_from_fork; + } + childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX); + sp -= STACK_FRAME_OVERHEAD; + + /* + * The way this works is that at some point in the future + * some task will call _switch to switch to the new task. + * That will pop off the stack frame created below and start + * the new task running at ret_from_fork. The new task will + * do some house keeping and then return from the fork or clone + * system call, using the stack frame created above. + */ + ((unsigned long *)sp)[0] = 0; + sp -= sizeof(struct pt_regs); + kregs = (struct pt_regs *) sp; + sp -= STACK_FRAME_OVERHEAD; + p->thread.ksp = sp; +#ifdef CONFIG_PPC32 + p->thread.ksp_limit = (unsigned long)task_stack_page(p) + + _ALIGN_UP(sizeof(struct thread_info), 16); +#endif +#ifdef CONFIG_HAVE_HW_BREAKPOINT + p->thread.ptrace_bps[0] = NULL; +#endif + + p->thread.fp_save_area = NULL; +#ifdef CONFIG_ALTIVEC + p->thread.vr_save_area = NULL; +#endif + + setup_ksp_vsid(p, sp); + +#ifdef CONFIG_PPC64 + if (cpu_has_feature(CPU_FTR_DSCR)) { + p->thread.dscr_inherit = current->thread.dscr_inherit; + p->thread.dscr = mfspr(SPRN_DSCR); + } + if (cpu_has_feature(CPU_FTR_HAS_PPR)) + p->thread.ppr = INIT_PPR; + + p->thread.tidr = 0; +#endif + kregs->nip = ppc_function_entry(f); + return 0; +} + +/* + * Set up a thread for executing a new program + */ +void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) +{ +#ifdef CONFIG_PPC64 + unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */ +#endif + + /* + * If we exec out of a kernel thread then thread.regs will not be + * set. Do it now. + */ + if (!current->thread.regs) { + struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; + current->thread.regs = regs - 1; + } + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + /* + * Clear any transactional state, we're exec()ing. The cause is + * not important as there will never be a recheckpoint so it's not + * user visible. + */ + if (MSR_TM_SUSPENDED(mfmsr())) + tm_reclaim_current(0); +#endif + + memset(regs->gpr, 0, sizeof(regs->gpr)); + regs->ctr = 0; + regs->link = 0; + regs->xer = 0; + regs->ccr = 0; + regs->gpr[1] = sp; + + /* + * We have just cleared all the nonvolatile GPRs, so make + * FULL_REGS(regs) return true. This is necessary to allow + * ptrace to examine the thread immediately after exec. + */ + regs->trap &= ~1UL; + +#ifdef CONFIG_PPC32 + regs->mq = 0; + regs->nip = start; + regs->msr = MSR_USER; +#else + if (!is_32bit_task()) { + unsigned long entry; + + if (is_elf2_task()) { + /* Look ma, no function descriptors! */ + entry = start; + + /* + * Ulrich says: + * The latest iteration of the ABI requires that when + * calling a function (at its global entry point), + * the caller must ensure r12 holds the entry point + * address (so that the function can quickly + * establish addressability). + */ + regs->gpr[12] = start; + /* Make sure that's restored on entry to userspace. */ + set_thread_flag(TIF_RESTOREALL); + } else { + unsigned long toc; + + /* start is a relocated pointer to the function + * descriptor for the elf _start routine. The first + * entry in the function descriptor is the entry + * address of _start and the second entry is the TOC + * value we need to use. + */ + __get_user(entry, (unsigned long __user *)start); + __get_user(toc, (unsigned long __user *)start+1); + + /* Check whether the e_entry function descriptor entries + * need to be relocated before we can use them. + */ + if (load_addr != 0) { + entry += load_addr; + toc += load_addr; + } + regs->gpr[2] = toc; + } + regs->nip = entry; + regs->msr = MSR_USER64; + } else { + regs->nip = start; + regs->gpr[2] = 0; + regs->msr = MSR_USER32; + } +#endif +#ifdef CONFIG_VSX + current->thread.used_vsr = 0; +#endif + current->thread.load_fp = 0; + memset(¤t->thread.fp_state, 0, sizeof(current->thread.fp_state)); + current->thread.fp_save_area = NULL; +#ifdef CONFIG_ALTIVEC + memset(¤t->thread.vr_state, 0, sizeof(current->thread.vr_state)); + current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */ + current->thread.vr_save_area = NULL; + current->thread.vrsave = 0; + current->thread.used_vr = 0; + current->thread.load_vec = 0; +#endif /* CONFIG_ALTIVEC */ +#ifdef CONFIG_SPE + memset(current->thread.evr, 0, sizeof(current->thread.evr)); + current->thread.acc = 0; + current->thread.spefscr = 0; + current->thread.used_spe = 0; +#endif /* CONFIG_SPE */ +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + current->thread.tm_tfhar = 0; + current->thread.tm_texasr = 0; + current->thread.tm_tfiar = 0; + current->thread.load_tm = 0; +#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ + + thread_pkey_regs_init(¤t->thread); +} +EXPORT_SYMBOL(start_thread); + +#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ + | PR_FP_EXC_RES | PR_FP_EXC_INV) + +int set_fpexc_mode(struct task_struct *tsk, unsigned int val) +{ + struct pt_regs *regs = tsk->thread.regs; + + /* This is a bit hairy. If we are an SPE enabled processor + * (have embedded fp) we store the IEEE exception enable flags in + * fpexc_mode. fpexc_mode is also used for setting FP exception + * mode (asyn, precise, disabled) for 'Classic' FP. */ + if (val & PR_FP_EXC_SW_ENABLE) { +#ifdef CONFIG_SPE + if (cpu_has_feature(CPU_FTR_SPE)) { + /* + * When the sticky exception bits are set + * directly by userspace, it must call prctl + * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE + * in the existing prctl settings) or + * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in + * the bits being set). <fenv.h> functions + * saving and restoring the whole + * floating-point environment need to do so + * anyway to restore the prctl settings from + * the saved environment. + */ + tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR); + tsk->thread.fpexc_mode = val & + (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); + return 0; + } else { + return -EINVAL; + } +#else + return -EINVAL; +#endif + } + + /* on a CONFIG_SPE this does not hurt us. The bits that + * __pack_fe01 use do not overlap with bits used for + * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits + * on CONFIG_SPE implementations are reserved so writing to + * them does not change anything */ + if (val > PR_FP_EXC_PRECISE) + return -EINVAL; + tsk->thread.fpexc_mode = __pack_fe01(val); + if (regs != NULL && (regs->msr & MSR_FP) != 0) + regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1)) + | tsk->thread.fpexc_mode; + return 0; +} + +int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) +{ + unsigned int val; + + if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) +#ifdef CONFIG_SPE + if (cpu_has_feature(CPU_FTR_SPE)) { + /* + * When the sticky exception bits are set + * directly by userspace, it must call prctl + * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE + * in the existing prctl settings) or + * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in + * the bits being set). <fenv.h> functions + * saving and restoring the whole + * floating-point environment need to do so + * anyway to restore the prctl settings from + * the saved environment. + */ + tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR); + val = tsk->thread.fpexc_mode; + } else + return -EINVAL; +#else + return -EINVAL; +#endif + else + val = __unpack_fe01(tsk->thread.fpexc_mode); + return put_user(val, (unsigned int __user *) adr); +} + +int set_endian(struct task_struct *tsk, unsigned int val) +{ + struct pt_regs *regs = tsk->thread.regs; + + if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) || + (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE))) + return -EINVAL; + + if (regs == NULL) + return -EINVAL; + + if (val == PR_ENDIAN_BIG) + regs->msr &= ~MSR_LE; + else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) + regs->msr |= MSR_LE; + else + return -EINVAL; + + return 0; +} + +int get_endian(struct task_struct *tsk, unsigned long adr) +{ + struct pt_regs *regs = tsk->thread.regs; + unsigned int val; + + if (!cpu_has_feature(CPU_FTR_PPC_LE) && + !cpu_has_feature(CPU_FTR_REAL_LE)) + return -EINVAL; + + if (regs == NULL) + return -EINVAL; + + if (regs->msr & MSR_LE) { + if (cpu_has_feature(CPU_FTR_REAL_LE)) + val = PR_ENDIAN_LITTLE; + else + val = PR_ENDIAN_PPC_LITTLE; + } else + val = PR_ENDIAN_BIG; + + return put_user(val, (unsigned int __user *)adr); +} + +int set_unalign_ctl(struct task_struct *tsk, unsigned int val) +{ + tsk->thread.align_ctl = val; + return 0; +} + +int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) +{ + return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr); +} + +static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, + unsigned long nbytes) +{ + unsigned long stack_page; + unsigned long cpu = task_cpu(p); + + /* + * Avoid crashing if the stack has overflowed and corrupted + * task_cpu(p), which is in the thread_info struct. + */ + if (cpu < NR_CPUS && cpu_possible(cpu)) { + stack_page = (unsigned long) hardirq_ctx[cpu]; + if (sp >= stack_page + sizeof(struct thread_struct) + && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + + stack_page = (unsigned long) softirq_ctx[cpu]; + if (sp >= stack_page + sizeof(struct thread_struct) + && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + } + return 0; +} + +int validate_sp(unsigned long sp, struct task_struct *p, + unsigned long nbytes) +{ + unsigned long stack_page = (unsigned long)task_stack_page(p); + + if (sp >= stack_page + sizeof(struct thread_struct) + && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + + return valid_irq_stack(sp, p, nbytes); +} + +EXPORT_SYMBOL(validate_sp); + +unsigned long get_wchan(struct task_struct *p) +{ + unsigned long ip, sp; + int count = 0; + + if (!p || p == current || p->state == TASK_RUNNING) + return 0; + + sp = p->thread.ksp; + if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) + return 0; + + do { + sp = READ_ONCE_NOCHECK(*(unsigned long *)sp); + if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) || + p->state == TASK_RUNNING) + return 0; + if (count > 0) { + ip = READ_ONCE_NOCHECK(((unsigned long *)sp)[STACK_FRAME_LR_SAVE]); + if (!in_sched_functions(ip)) + return ip; + } + } while (count++ < 16); + return 0; +} + +static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; + +void show_stack(struct task_struct *tsk, unsigned long *stack) +{ + unsigned long sp, ip, lr, newsp; + int count = 0; + int firstframe = 1; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + int curr_frame = current->curr_ret_stack; + extern void return_to_handler(void); + unsigned long rth = (unsigned long)return_to_handler; +#endif + + sp = (unsigned long) stack; + if (tsk == NULL) + tsk = current; + if (sp == 0) { + if (tsk == current) + sp = current_stack_pointer(); + else + sp = tsk->thread.ksp; + } + + lr = 0; + printk("Call Trace:\n"); + do { + if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) + return; + + stack = (unsigned long *) sp; + newsp = stack[0]; + ip = stack[STACK_FRAME_LR_SAVE]; + if (!firstframe || ip != lr) { + printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip); +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + if ((ip == rth) && curr_frame >= 0) { + pr_cont(" (%pS)", + (void *)current->ret_stack[curr_frame].ret); + curr_frame--; + } +#endif + if (firstframe) + pr_cont(" (unreliable)"); + pr_cont("\n"); + } + firstframe = 0; + + /* + * See if this is an exception frame. + * We look for the "regshere" marker in the current frame. + */ + if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) + && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { + struct pt_regs *regs = (struct pt_regs *) + (sp + STACK_FRAME_OVERHEAD); + lr = regs->link; + printk("--- interrupt: %lx at %pS\n LR = %pS\n", + regs->trap, (void *)regs->nip, (void *)lr); + firstframe = 1; + } + + sp = newsp; + } while (count++ < kstack_depth_to_print); +} + +#ifdef CONFIG_PPC64 +/* Called with hard IRQs off */ +void notrace __ppc64_runlatch_on(void) +{ + struct thread_info *ti = current_thread_info(); + + if (cpu_has_feature(CPU_FTR_ARCH_206)) { + /* + * Least significant bit (RUN) is the only writable bit of + * the CTRL register, so we can avoid mfspr. 2.06 is not the + * earliest ISA where this is the case, but it's convenient. + */ + mtspr(SPRN_CTRLT, CTRL_RUNLATCH); + } else { + unsigned long ctrl; + + /* + * Some architectures (e.g., Cell) have writable fields other + * than RUN, so do the read-modify-write. + */ + ctrl = mfspr(SPRN_CTRLF); + ctrl |= CTRL_RUNLATCH; + mtspr(SPRN_CTRLT, ctrl); + } + + ti->local_flags |= _TLF_RUNLATCH; +} + +/* Called with hard IRQs off */ +void notrace __ppc64_runlatch_off(void) +{ + struct thread_info *ti = current_thread_info(); + + ti->local_flags &= ~_TLF_RUNLATCH; + + if (cpu_has_feature(CPU_FTR_ARCH_206)) { + mtspr(SPRN_CTRLT, 0); + } else { + unsigned long ctrl; + + ctrl = mfspr(SPRN_CTRLF); + ctrl &= ~CTRL_RUNLATCH; + mtspr(SPRN_CTRLT, ctrl); + } +} +#endif /* CONFIG_PPC64 */ + +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 & ~0xf; +} + +static inline unsigned long brk_rnd(void) +{ + unsigned long rnd = 0; + + /* 8MB for 32bit, 1GB for 64bit */ + if (is_32bit_task()) + rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT))); + else + rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT))); + + return rnd << PAGE_SHIFT; +} + +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + unsigned long base = mm->brk; + unsigned long ret; + +#ifdef CONFIG_PPC_BOOK3S_64 + /* + * If we are using 1TB segments and we are allowed to randomise + * the heap, we can put it above 1TB so it is backed by a 1TB + * segment. Otherwise the heap will be in the bottom 1TB + * which always uses 256MB segments and this may result in a + * performance penalty. We don't need to worry about radix. For + * radix, mmu_highuser_ssize remains unchanged from 256MB. + */ + if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T)) + base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T); +#endif + + ret = PAGE_ALIGN(base + brk_rnd()); + + if (ret < mm->brk) + return mm->brk; + + return ret; +} + |