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Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 2308 |
1 files changed, 2308 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c new file mode 100644 index 000000000..f2cbad522 --- /dev/null +++ b/arch/powerpc/kernel/process.c @@ -0,0 +1,2308 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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) + */ + +#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/hw_breakpoint.h> +#include <linux/uaccess.h> +#include <linux/pkeys.h> +#include <linux/seq_buf.h> + +#include <asm/interrupt.h> +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/mmu.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 <asm/stacktrace.h> +#include <asm/hw_breakpoint.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)) { + regs_set_return_msr(&tsk->thread.ckpt_regs, + 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); + +/* notrace because it's called by restore_math */ +unsigned long notrace msr_check_and_set(unsigned long bits) +{ + unsigned long oldmsr = mfmsr(); + unsigned long newmsr; + + newmsr = oldmsr | bits; + + if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP)) + newmsr |= MSR_VSX; + + if (oldmsr != newmsr) + newmsr = mtmsr_isync_irqsafe(newmsr); + + return newmsr; +} +EXPORT_SYMBOL_GPL(msr_check_and_set); + +/* notrace because it's called by restore_math */ +void notrace __msr_check_and_clear(unsigned long bits) +{ + unsigned long oldmsr = mfmsr(); + unsigned long newmsr; + + newmsr = oldmsr & ~bits; + + if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP)) + newmsr &= ~MSR_VSX; + + if (oldmsr != newmsr) + mtmsr_isync_irqsafe(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); + if (cpu_has_feature(CPU_FTR_VSX)) + msr &= ~MSR_VSX; + regs_set_return_msr(tsk->thread.regs, 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); +#else +static inline void __giveup_fpu(struct task_struct *tsk) { } +#endif /* CONFIG_PPC_FPU */ + +#ifdef CONFIG_ALTIVEC +static void __giveup_altivec(struct task_struct *tsk) +{ + unsigned long msr; + + save_altivec(tsk); + msr = tsk->thread.regs->msr; + msr &= ~MSR_VEC; + if (cpu_has_feature(CPU_FTR_VSX)) + msr &= ~MSR_VSX; + regs_set_return_msr(tsk->thread.regs, 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); +#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 setting 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); +#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) +{ + if (IS_ENABLED(CONFIG_PPC_FPU)) + msr_all_available |= MSR_FP; + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + msr_all_available |= MSR_VEC; + if (cpu_has_feature(CPU_FTR_VSX)) + msr_all_available |= MSR_VSX; + if (cpu_has_feature(CPU_FTR_SPE)) + msr_all_available |= MSR_SPE; + + 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))); + + if (usermsr & MSR_FP) + __giveup_fpu(tsk); + if (usermsr & MSR_VEC) + __giveup_altivec(tsk); + if (usermsr & MSR_SPE) + __giveup_spe(tsk); + + msr_check_and_clear(msr_all_available); +} +EXPORT_SYMBOL(giveup_all); + +#ifdef CONFIG_PPC_BOOK3S_64 +#ifdef CONFIG_PPC_FPU +static bool should_restore_fp(void) +{ + if (current->thread.load_fp) { + current->thread.load_fp++; + return true; + } + return false; +} + +static void do_restore_fp(void) +{ + load_fp_state(¤t->thread.fp_state); +} +#else +static bool should_restore_fp(void) { return false; } +static void do_restore_fp(void) { } +#endif /* CONFIG_PPC_FPU */ + +#ifdef CONFIG_ALTIVEC +static bool should_restore_altivec(void) +{ + if (cpu_has_feature(CPU_FTR_ALTIVEC) && (current->thread.load_vec)) { + current->thread.load_vec++; + return true; + } + return false; +} + +static void do_restore_altivec(void) +{ + load_vr_state(¤t->thread.vr_state); + current->thread.used_vr = 1; +} +#else +static bool should_restore_altivec(void) { return false; } +static void do_restore_altivec(void) { } +#endif /* CONFIG_ALTIVEC */ + +static bool should_restore_vsx(void) +{ + if (cpu_has_feature(CPU_FTR_VSX)) + return true; + return false; +} +#ifdef CONFIG_VSX +static void do_restore_vsx(void) +{ + current->thread.used_vsr = 1; +} +#else +static void do_restore_vsx(void) { } +#endif /* CONFIG_VSX */ + +/* + * The exception exit path calls restore_math() with interrupts hard disabled + * but the soft irq state not "reconciled". ftrace code that calls + * local_irq_save/restore causes warnings. + * + * Rather than complicate the exit path, just don't trace restore_math. This + * could be done by having ftrace entry code check for this un-reconciled + * condition where MSR[EE]=0 and PACA_IRQ_HARD_DIS is not set, and + * temporarily fix it up for the duration of the ftrace call. + */ +void notrace restore_math(struct pt_regs *regs) +{ + unsigned long msr; + unsigned long new_msr = 0; + + msr = regs->msr; + + /* + * new_msr tracks the facilities that are to be restored. Only reload + * if the bit is not set in the user MSR (if it is set, the registers + * are live for the user thread). + */ + if ((!(msr & MSR_FP)) && should_restore_fp()) + new_msr |= MSR_FP; + + if ((!(msr & MSR_VEC)) && should_restore_altivec()) + new_msr |= MSR_VEC; + + if ((!(msr & MSR_VSX)) && should_restore_vsx()) { + if (((msr | new_msr) & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC)) + new_msr |= MSR_VSX; + } + + if (new_msr) { + unsigned long fpexc_mode = 0; + + msr_check_and_set(new_msr); + + if (new_msr & MSR_FP) { + do_restore_fp(); + + // This also covers VSX, because VSX implies FP + fpexc_mode = current->thread.fpexc_mode; + } + + if (new_msr & MSR_VEC) + do_restore_altivec(); + + if (new_msr & MSR_VSX) + do_restore_vsx(); + + msr_check_and_clear(new_msr); + + regs_set_return_msr(regs, regs->msr | new_msr | fpexc_mode); + } +} +#endif /* CONFIG_PPC_BOOK3S_64 */ + +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); +} + +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 */ + +static void do_break_handler(struct pt_regs *regs) +{ + struct arch_hw_breakpoint null_brk = {0}; + struct arch_hw_breakpoint *info; + ppc_inst_t instr = ppc_inst(0); + int type = 0; + int size = 0; + unsigned long ea; + int i; + + /* + * If underneath hw supports only one watchpoint, we know it + * caused exception. 8xx also falls into this category. + */ + if (nr_wp_slots() == 1) { + __set_breakpoint(0, &null_brk); + current->thread.hw_brk[0] = null_brk; + current->thread.hw_brk[0].flags |= HW_BRK_FLAG_DISABLED; + return; + } + + /* Otherwise find out which DAWR caused exception and disable it. */ + wp_get_instr_detail(regs, &instr, &type, &size, &ea); + + for (i = 0; i < nr_wp_slots(); i++) { + info = ¤t->thread.hw_brk[i]; + if (!info->address) + continue; + + if (wp_check_constraints(regs, instr, ea, type, size, info)) { + __set_breakpoint(i, &null_brk); + current->thread.hw_brk[i] = null_brk; + current->thread.hw_brk[i].flags |= HW_BRK_FLAG_DISABLED; + } + } +} + +DEFINE_INTERRUPT_HANDLER(do_break) +{ + current->thread.trap_nr = TRAP_HWBKPT; + if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, regs->dsisr, + 11, SIGSEGV) == NOTIFY_STOP) + return; + + if (debugger_break_match(regs)) + return; + + /* + * We reach here only when watchpoint exception is generated by ptrace + * event (or hw is buggy!). Now if CONFIG_HAVE_HW_BREAKPOINT is set, + * watchpoint is already handled by hw_breakpoint_handler() so we don't + * have to do anything. But when CONFIG_HAVE_HW_BREAKPOINT is not set, + * we need to manually handle the watchpoint here. + */ + if (!IS_ENABLED(CONFIG_HAVE_HW_BREAKPOINT)) + do_break_handler(regs); + + /* Deliver the signal to userspace */ + force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar); +} +#endif /* CONFIG_PPC_ADV_DEBUG_REGS */ + +static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk[HBP_NUM_MAX]); + +#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(int i, struct arch_hw_breakpoint *brk) +{ + preempt_disable(); + __set_breakpoint(i, brk); + preempt_enable(); +} + +static void set_debug_reg_defaults(struct thread_struct *thread) +{ + int i; + struct arch_hw_breakpoint null_brk = {0}; + + for (i = 0; i < nr_wp_slots(); i++) { + thread->hw_brk[i] = null_brk; + if (ppc_breakpoint_available()) + set_breakpoint(i, &thread->hw_brk[i]); + } +} + +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; + /* no need to check hw_len. it's calculated from address and len */ + return true; +} + +static void switch_hw_breakpoint(struct task_struct *new) +{ + int i; + + for (i = 0; i < nr_wp_slots(); i++) { + if (likely(hw_brk_match(this_cpu_ptr(¤t_brk[i]), + &new->thread.hw_brk[i]))) + continue; + + __set_breakpoint(i, &new->thread.hw_brk[i]); + } +} +#endif /* !CONFIG_HAVE_HW_BREAKPOINT */ +#endif /* CONFIG_PPC_ADV_DEBUG_REGS */ + +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); + + if (IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) { + mtspr(SPRN_DAC1, dabr); + if (IS_ENABLED(CONFIG_PPC_47x)) + isync(); + return 0; + } else if (IS_ENABLED(CONFIG_PPC_BOOK3S)) { + mtspr(SPRN_DABR, dabr); + if (cpu_has_feature(CPU_FTR_DABRX)) + mtspr(SPRN_DABRX, dabrx); + return 0; + } else { + return -EINVAL; + } +} + +static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk) +{ + unsigned long lctrl1 = LCTRL1_CTE_GT | LCTRL1_CTF_LT | LCTRL1_CRWE_RW | + LCTRL1_CRWF_RW; + unsigned long lctrl2 = LCTRL2_LW0EN | LCTRL2_LW0LADC | LCTRL2_SLW0EN; + unsigned long start_addr = ALIGN_DOWN(brk->address, HW_BREAKPOINT_SIZE); + unsigned long end_addr = ALIGN(brk->address + brk->len, HW_BREAKPOINT_SIZE); + + if (start_addr == 0) + lctrl2 |= LCTRL2_LW0LA_F; + else if (end_addr == 0) + lctrl2 |= LCTRL2_LW0LA_E; + else + lctrl2 |= LCTRL2_LW0LA_EandF; + + mtspr(SPRN_LCTRL2, 0); + + if ((brk->type & HW_BRK_TYPE_RDWR) == 0) + return 0; + + if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_READ) + lctrl1 |= LCTRL1_CRWE_RO | LCTRL1_CRWF_RO; + if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_WRITE) + lctrl1 |= LCTRL1_CRWE_WO | LCTRL1_CRWF_WO; + + mtspr(SPRN_CMPE, start_addr - 1); + mtspr(SPRN_CMPF, end_addr); + mtspr(SPRN_LCTRL1, lctrl1); + mtspr(SPRN_LCTRL2, lctrl2); + + return 0; +} + +void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk) +{ + memcpy(this_cpu_ptr(¤t_brk[nr]), brk, sizeof(*brk)); + + if (dawr_enabled()) + // Power8 or later + set_dawr(nr, brk); + else if (IS_ENABLED(CONFIG_PPC_8xx)) + set_breakpoint_8xx(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 (dawr_enabled()) + return true; /* POWER8 DAWR or POWER9 forced 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); + +#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_set_return_msr(regs, regs->msr | msr_diff); +} + +#else /* !CONFIG_PPC_TRANSACTIONAL_MEM */ +#define tm_recheckpoint_new_task(new) +#define __switch_to_tm(prev, new) +void tm_reclaim_current(uint8_t cause) {} +#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_SPE + if (cpu_has_feature(CPU_FTR_SPE)) + t->spefscr = mfspr(SPRN_SPEFSCR); +#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 +} + +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE +void kvmppc_save_user_regs(void) +{ + unsigned long usermsr; + + if (!current->thread.regs) + return; + + usermsr = current->thread.regs->msr; + + /* Caller has enabled FP/VEC/VSX/TM in MSR */ + if (usermsr & MSR_FP) + __giveup_fpu(current); + if (usermsr & MSR_VEC) + __giveup_altivec(current); + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + if (usermsr & MSR_TM) { + current->thread.tm_tfhar = mfspr(SPRN_TFHAR); + current->thread.tm_tfiar = mfspr(SPRN_TFIAR); + current->thread.tm_texasr = mfspr(SPRN_TEXASR); + current->thread.regs->msr &= ~MSR_TM; + } +#endif +} +EXPORT_SYMBOL_GPL(kvmppc_save_user_regs); + +void kvmppc_save_current_sprs(void) +{ + save_sprs(¤t->thread); +} +EXPORT_SYMBOL_GPL(kvmppc_save_current_sprs); +#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */ + +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_SPE + if (cpu_has_feature(CPU_FTR_SPE) && + old_thread->spefscr != new_thread->spefscr) + mtspr(SPRN_SPEFSCR, new_thread->spefscr); +#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 + +} + +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_64S_HASH_MMU + struct ppc64_tlb_batch *batch; +#endif + + new_thread = &new->thread; + old_thread = ¤t->thread; + + WARN_ON(!irqs_disabled()); + +#ifdef CONFIG_PPC_64S_HASH_MMU + 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; + } + + /* + * On POWER9 the copy-paste buffer can only paste 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. ISA v3.1 supports paste into local memory. + */ + if (new->mm && (cpu_has_feature(CPU_FTR_ARCH_31) || + atomic_read(&new->mm->context.vas_windows))) + asm volatile(PPC_CP_ABORT); +#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 + switch_hw_breakpoint(new); +#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() and set_return_regs_changed() 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); + + set_return_regs_changed(); /* _switch changes stack (and regs) */ + + if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64)) + kuap_assert_locked(); + + last = _switch(old_thread, new_thread); + + /* + * Nothing after _switch will be run for newly created tasks, + * because they switch directly to ret_from_fork/ret_from_kernel_thread + * etc. Code added here should have a comment explaining why that is + * okay. + */ + +#ifdef CONFIG_PPC_BOOK3S_64 +#ifdef CONFIG_PPC_64S_HASH_MMU + /* + * This applies to a process that was context switched while inside + * arch_enter_lazy_mmu_mode(), to re-activate the batch that was + * deactivated above, before _switch(). This will never be the case + * for new tasks. + */ + 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; + } +#endif + + /* + * Math facilities are masked out of the child MSR in copy_thread. + * A new task does not need to restore_math because it will + * demand fault them. + */ + if (current->thread.regs) + restore_math(current->thread.regs); +#endif /* CONFIG_PPC_BOOK3S_64 */ + + return last; +} + +#define NR_INSN_TO_PRINT 16 + +static void show_instructions(struct pt_regs *regs) +{ + int i; + unsigned long nip = regs->nip; + unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int)); + + printk("Instruction dump:"); + + /* + * If we were executing with the MMU off for instructions, adjust pc + * rather than printing XXXXXXXX. + */ + if (!IS_ENABLED(CONFIG_BOOKE) && !(regs->msr & MSR_IR)) { + pc = (unsigned long)phys_to_virt(pc); + nip = (unsigned long)phys_to_virt(regs->nip); + } + + for (i = 0; i < NR_INSN_TO_PRINT; i++) { + int instr; + + if (!(i % 8)) + pr_cont("\n"); + + if (!__kernel_text_address(pc) || + get_kernel_nofault(instr, (const void *)pc)) { + pr_cont("XXXXXXXX "); + } else { + if (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 n = NR_INSN_TO_PRINT; + struct seq_buf s; + char buf[96]; /* enough for 8 times 9 + 2 chars */ + + pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int)); + + seq_buf_init(&s, buf, sizeof(buf)); + + while (n) { + int i; + + seq_buf_clear(&s); + + for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) { + int instr; + + if (copy_from_user_nofault(&instr, (void __user *)pc, + sizeof(instr))) { + seq_buf_printf(&s, "XXXXXXXX "); + continue; + } + seq_buf_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr); + } + + if (!seq_buf_has_overflowed(&s)) + pr_info("%s[%d]: code: %s\n", current->comm, + current->pid, s.buffer); + } +} + +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 +#else +#define REG "%08lx" +#define REGS_PER_LINE 8 +#endif + +static void __show_regs(struct pt_regs *regs) +{ + int i, trap; + + 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_is_syscall(regs) && cpu_has_feature(CPU_FTR_CFAR)) + pr_cont("CFAR: "REG" ", regs->orig_gpr3); + if (trap == INTERRUPT_MACHINE_CHECK || + trap == INTERRUPT_DATA_STORAGE || + trap == INTERRUPT_ALIGNMENT) { + if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE)) + pr_cont("DEAR: "REG" ESR: "REG" ", regs->dear, regs->esr); + else + pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr); + } + +#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]); + } + pr_cont("\n"); + /* + * Lookup NIP late so we have the best change of getting the + * above info out without failing + */ + if (IS_ENABLED(CONFIG_KALLSYMS)) { + printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip); + printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link); + } +} + +void show_regs(struct pt_regs *regs) +{ + show_regs_print_info(KERN_DEFAULT); + __show_regs(regs); + show_stack(current, (unsigned long *) regs->gpr[1], KERN_DEFAULT); + 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 */ +} + +void arch_setup_new_exec(void) +{ + +#ifdef CONFIG_PPC_BOOK3S_64 + if (!radix_enabled()) + hash__setup_new_exec(); +#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_MEM_KEYS + current->thread.regs->amr = default_amr; + current->thread.regs->iamr = default_iamr; +#endif +} + +#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 */ + +/* + * 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_64S_HASH_MMU + 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(struct task_struct *p, const struct kernel_clone_args *args) +{ + unsigned long clone_flags = args->flags; + unsigned long usp = args->stack; + unsigned long tls = args->tls; + struct pt_regs *childregs, *kregs; + extern void ret_from_fork(void); + extern void ret_from_fork_scv(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); +#ifdef CONFIG_HAVE_HW_BREAKPOINT + int i; +#endif + + klp_init_thread_info(p); + + /* Copy registers */ + sp -= sizeof(struct pt_regs); + childregs = (struct pt_regs *) sp; + if (unlikely(args->fn)) { + /* kernel thread */ + memset(childregs, 0, sizeof(struct pt_regs)); + childregs->gpr[1] = sp + sizeof(struct pt_regs); + /* function */ + if (args->fn) + childregs->gpr[14] = ppc_function_entry((void *)args->fn); +#ifdef CONFIG_PPC64 + clear_tsk_thread_flag(p, TIF_32BIT); + childregs->softe = IRQS_ENABLED; +#endif + childregs->gpr[15] = (unsigned long)args->fn_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(); + *childregs = *regs; + if (usp) + childregs->gpr[1] = usp; + p->thread.regs = childregs; + /* 64s sets this in ret_from_fork */ + if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64)) + childregs->gpr[3] = 0; /* Result from fork() */ + if (clone_flags & CLONE_SETTLS) { + if (!is_32bit_task()) + childregs->gpr[13] = tls; + else + childregs->gpr[2] = tls; + } + + if (trap_is_scv(regs)) + f = ret_from_fork_scv; + else + 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_HAVE_HW_BREAKPOINT + for (i = 0; i < nr_wp_slots(); i++) + p->thread.ptrace_bps[i] = NULL; +#endif + +#ifdef CONFIG_PPC_FPU_REGS + p->thread.fp_save_area = NULL; +#endif +#ifdef CONFIG_ALTIVEC + p->thread.vr_save_area = NULL; +#endif +#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP) + p->thread.kuap = KUAP_NONE; +#endif +#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP) + p->thread.pid = MMU_NO_CONTEXT; +#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)) + childregs->ppr = DEFAULT_PPR; + + p->thread.tidr = 0; +#endif + /* + * Run with the current AMR value of the kernel + */ +#ifdef CONFIG_PPC_PKEY + if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) + kregs->amr = AMR_KUAP_BLOCKED; + + if (mmu_has_feature(MMU_FTR_BOOK3S_KUEP)) + kregs->iamr = AMR_KUEP_BLOCKED; +#endif + kregs->nip = ppc_function_entry(f); + return 0; +} + +void preload_new_slb_context(unsigned long start, unsigned long sp); + +/* + * 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 */ + + if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !radix_enabled()) + preload_new_slb_context(start, sp); +#endif + +#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(®s->gpr[1], 0, sizeof(regs->gpr) - sizeof(regs->gpr[0])); + regs->ctr = 0; + regs->link = 0; + regs->xer = 0; + regs->ccr = 0; + regs->gpr[1] = sp; + +#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_set_return_ip(regs, entry); + regs_set_return_msr(regs, MSR_USER64); + } else { + regs->gpr[2] = 0; + regs_set_return_ip(regs, start); + regs_set_return_msr(regs, MSR_USER32); + } + +#endif +#ifdef CONFIG_VSX + current->thread.used_vsr = 0; +#endif + current->thread.load_slb = 0; + current->thread.load_fp = 0; +#ifdef CONFIG_PPC_FPU_REGS + memset(¤t->thread.fp_state, 0, sizeof(current->thread.fp_state)); + current->thread.fp_save_area = NULL; +#endif +#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 */ +} +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) { + 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. + */ +#ifdef CONFIG_SPE + tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR); + tsk->thread.fpexc_mode = val & + (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); +#endif + return 0; + } else { + return -EINVAL; + } + } + + /* 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_set_return_msr(regs, (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 = 0; + + if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) { + 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. + */ +#ifdef CONFIG_SPE + tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR); + val = tsk->thread.fpexc_mode; +#endif + } else + return -EINVAL; + } 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_set_return_msr(regs, regs->msr & ~MSR_LE); + else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) + regs_set_return_msr(regs, 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); + + stack_page = (unsigned long)hardirq_ctx[cpu]; + if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + + stack_page = (unsigned long)softirq_ctx[cpu]; + if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + + return 0; +} + +static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p, + unsigned long nbytes) +{ +#ifdef CONFIG_PPC64 + unsigned long stack_page; + unsigned long cpu = task_cpu(p); + + if (!paca_ptrs) + return 0; + + stack_page = (unsigned long)paca_ptrs[cpu]->emergency_sp - THREAD_SIZE; + if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + +# ifdef CONFIG_PPC_BOOK3S_64 + stack_page = (unsigned long)paca_ptrs[cpu]->nmi_emergency_sp - THREAD_SIZE; + if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + + stack_page = (unsigned long)paca_ptrs[cpu]->mc_emergency_sp - THREAD_SIZE; + if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; +# endif +#endif + + 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 < THREAD_SIZE) + return 0; + + if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + + if (valid_irq_stack(sp, p, nbytes)) + return 1; + + return valid_emergency_stack(sp, p, nbytes); +} + +EXPORT_SYMBOL(validate_sp); + +static unsigned long ___get_wchan(struct task_struct *p) +{ + unsigned long ip, sp; + int count = 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) || + task_is_running(p)) + 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; +} + +unsigned long __get_wchan(struct task_struct *p) +{ + unsigned long ret; + + if (!try_get_task_stack(p)) + return 0; + + ret = ___get_wchan(p); + + put_task_stack(p); + + return ret; +} + +static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; + +void __no_sanitize_address show_stack(struct task_struct *tsk, + unsigned long *stack, + const char *loglvl) +{ + unsigned long sp, ip, lr, newsp; + int count = 0; + int firstframe = 1; + unsigned long ret_addr; + int ftrace_idx = 0; + + if (tsk == NULL) + tsk = current; + + if (!try_get_task_stack(tsk)) + return; + + sp = (unsigned long) stack; + if (sp == 0) { + if (tsk == current) + sp = current_stack_frame(); + else + sp = tsk->thread.ksp; + } + + lr = 0; + printk("%sCall Trace:\n", loglvl); + do { + if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) + break; + + stack = (unsigned long *) sp; + newsp = stack[0]; + ip = stack[STACK_FRAME_LR_SAVE]; + if (!firstframe || ip != lr) { + printk("%s["REG"] ["REG"] %pS", + loglvl, sp, ip, (void *)ip); + ret_addr = ftrace_graph_ret_addr(current, + &ftrace_idx, ip, stack); + if (ret_addr != ip) + pr_cont(" (%pS)", (void *)ret_addr); + 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_FRAME_WITH_PT_REGS) + && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { + struct pt_regs *regs = (struct pt_regs *) + (sp + STACK_FRAME_OVERHEAD); + + lr = regs->link; + printk("%s--- interrupt: %lx at %pS\n", + loglvl, regs->trap, (void *)regs->nip); + __show_regs(regs); + printk("%s--- interrupt: %lx\n", + loglvl, regs->trap); + + firstframe = 1; + } + + sp = newsp; + } while (count++ < kstack_depth_to_print); + + put_task_stack(tsk); +} + +#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 -= prandom_u32_max(PAGE_SIZE); + return sp & ~0xf; +} |