/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_PPC64 #include #endif #include #include #include /* 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); #ifndef CONFIG_SMP struct task_struct *last_task_used_math = NULL; struct task_struct *last_task_used_altivec = NULL; struct task_struct *last_task_used_vsx = NULL; struct task_struct *last_task_used_spe = NULL; #endif #ifdef CONFIG_PPC_TRANSACTIONAL_MEM void giveup_fpu_maybe_transactional(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.tm_orig_msr = tsk->thread.regs->msr; set_thread_flag(TIF_RESTORE_TM); } giveup_fpu(tsk); } void giveup_altivec_maybe_transactional(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.tm_orig_msr = tsk->thread.regs->msr; set_thread_flag(TIF_RESTORE_TM); } giveup_altivec(tsk); } #else #define giveup_fpu_maybe_transactional(tsk) giveup_fpu(tsk) #define giveup_altivec_maybe_transactional(tsk) giveup_altivec(tsk) #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ #ifdef CONFIG_PPC_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) { #ifdef CONFIG_SMP /* * 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 on SMP, * there is something wrong if a stopped child appears * to still have its FP state in the CPU registers. */ BUG_ON(tsk != current); #endif giveup_fpu_maybe_transactional(tsk); } preempt_enable(); } } EXPORT_SYMBOL_GPL(flush_fp_to_thread); #endif /* CONFIG_PPC_FPU */ void enable_kernel_fp(void) { WARN_ON(preemptible()); #ifdef CONFIG_SMP if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) giveup_fpu_maybe_transactional(current); else giveup_fpu(NULL); /* just enables FP for kernel */ #else giveup_fpu_maybe_transactional(last_task_used_math); #endif /* CONFIG_SMP */ } EXPORT_SYMBOL(enable_kernel_fp); #ifdef CONFIG_ALTIVEC void enable_kernel_altivec(void) { WARN_ON(preemptible()); #ifdef CONFIG_SMP if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) giveup_altivec_maybe_transactional(current); else giveup_altivec_notask(); #else giveup_altivec_maybe_transactional(last_task_used_altivec); #endif /* CONFIG_SMP */ } 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) { #ifdef CONFIG_SMP BUG_ON(tsk != current); #endif giveup_altivec_maybe_transactional(tsk); } preempt_enable(); } } EXPORT_SYMBOL_GPL(flush_altivec_to_thread); #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_VSX #if 0 /* not currently used, but some crazy RAID module might want to later */ void enable_kernel_vsx(void) { WARN_ON(preemptible()); #ifdef CONFIG_SMP if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) giveup_vsx(current); else giveup_vsx(NULL); /* just enable vsx for kernel - force */ #else giveup_vsx(last_task_used_vsx); #endif /* CONFIG_SMP */ } EXPORT_SYMBOL(enable_kernel_vsx); #endif void giveup_vsx(struct task_struct *tsk) { giveup_fpu_maybe_transactional(tsk); giveup_altivec_maybe_transactional(tsk); __giveup_vsx(tsk); } EXPORT_SYMBOL(giveup_vsx); void flush_vsx_to_thread(struct task_struct *tsk) { if (tsk->thread.regs) { preempt_disable(); if (tsk->thread.regs->msr & MSR_VSX) { #ifdef CONFIG_SMP BUG_ON(tsk != current); #endif giveup_vsx(tsk); } preempt_enable(); } } EXPORT_SYMBOL_GPL(flush_vsx_to_thread); #endif /* CONFIG_VSX */ #ifdef CONFIG_SPE void enable_kernel_spe(void) { WARN_ON(preemptible()); #ifdef CONFIG_SMP if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) giveup_spe(current); else giveup_spe(NULL); /* just enable SPE for kernel - force */ #else giveup_spe(last_task_used_spe); #endif /* __SMP __ */ } 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) { #ifdef CONFIG_SMP BUG_ON(tsk != current); #endif tsk->thread.spefscr = mfspr(SPRN_SPEFSCR); giveup_spe(tsk); } preempt_enable(); } } #endif /* CONFIG_SPE */ #ifndef CONFIG_SMP /* * If we are doing lazy switching of CPU state (FP, altivec or SPE), * and the current task has some state, discard it. */ void discard_lazy_cpu_state(void) { preempt_disable(); if (last_task_used_math == current) last_task_used_math = NULL; #ifdef CONFIG_ALTIVEC if (last_task_used_altivec == current) last_task_used_altivec = NULL; #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_VSX if (last_task_used_vsx == current) last_task_used_vsx = NULL; #endif /* CONFIG_VSX */ #ifdef CONFIG_SPE if (last_task_used_spe == current) last_task_used_spe = NULL; #endif preempt_enable(); } #endif /* CONFIG_SMP */ #ifdef CONFIG_PPC_ADV_DEBUG_REGS void do_send_trap(struct pt_regs *regs, unsigned long address, unsigned long error_code, int signal_code, int breakpt) { siginfo_t info; current->thread.trap_nr = signal_code; if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, 11, SIGSEGV) == NOTIFY_STOP) return; /* Deliver the signal to userspace */ info.si_signo = SIGTRAP; info.si_errno = breakpt; /* breakpoint or watchpoint id */ info.si_code = signal_code; info.si_addr = (void __user *)address; force_sig_info(SIGTRAP, &info, current); } #else /* !CONFIG_PPC_ADV_DEBUG_REGS */ void do_break (struct pt_regs *regs, unsigned long address, unsigned long error_code) { siginfo_t info; current->thread.trap_nr = TRAP_HWBKPT; if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, 11, SIGSEGV) == NOTIFY_STOP) return; if (debugger_break_match(regs)) return; /* Clear the breakpoint */ hw_breakpoint_disable(); /* Deliver the signal to userspace */ info.si_signo = SIGTRAP; info.si_errno = 0; info.si_code = TRAP_HWBKPT; info.si_addr = (void __user *)address; force_sig_info(SIGTRAP, &info, current); } #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk); #ifdef CONFIG_PPC_ADV_DEBUG_REGS /* * Set the debug registers back to their default "safe" values. */ static void set_debug_reg_defaults(struct thread_struct *thread) { thread->debug.iac1 = thread->debug.iac2 = 0; #if CONFIG_PPC_ADV_DEBUG_IACS > 2 thread->debug.iac3 = thread->debug.iac4 = 0; #endif thread->debug.dac1 = thread->debug.dac2 = 0; #if CONFIG_PPC_ADV_DEBUG_DVCS > 0 thread->debug.dvc1 = thread->debug.dvc2 = 0; #endif thread->debug.dbcr0 = 0; #ifdef CONFIG_BOOKE /* * Force User/Supervisor bits to b11 (user-only MSR[PR]=1) */ thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US | DBCR1_IAC3US | DBCR1_IAC4US; /* * Force Data Address Compare User/Supervisor bits to be User-only * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0. */ thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US; #else thread->debug.dbcr1 = 0; #endif } static void prime_debug_regs(struct debug_reg *debug) { /* * We could have inherited MSR_DE from userspace, since * it doesn't get cleared on exception entry. Make sure * MSR_DE is clear before we enable any debug events. */ mtmsr(mfmsr() & ~MSR_DE); mtspr(SPRN_IAC1, debug->iac1); mtspr(SPRN_IAC2, debug->iac2); #if CONFIG_PPC_ADV_DEBUG_IACS > 2 mtspr(SPRN_IAC3, debug->iac3); mtspr(SPRN_IAC4, debug->iac4); #endif mtspr(SPRN_DAC1, debug->dac1); mtspr(SPRN_DAC2, debug->dac2); #if CONFIG_PPC_ADV_DEBUG_DVCS > 0 mtspr(SPRN_DVC1, debug->dvc1); mtspr(SPRN_DVC2, debug->dvc2); #endif mtspr(SPRN_DBCR0, debug->dbcr0); mtspr(SPRN_DBCR1, debug->dbcr1); #ifdef CONFIG_BOOKE mtspr(SPRN_DBCR2, debug->dbcr2); #endif } /* * Unless neither the old or new thread are making use of the * debug registers, set the debug registers from the values * 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_debug_reg_defaults(struct thread_struct *thread) { thread->hw_brk.address = 0; thread->hw_brk.type = 0; 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; } #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)) set_dawr(brk); else set_dabr(brk); } void set_breakpoint(struct arch_hw_breakpoint *brk) { preempt_disable(); __set_breakpoint(brk); preempt_enable(); } #ifdef CONFIG_PPC64 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); #endif 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 void tm_reclaim_thread(struct thread_struct *thr, struct thread_info *ti, uint8_t cause) { unsigned long msr_diff = 0; /* * If FP/VSX registers have been already saved to the * thread_struct, move them to the transact_fp array. * We clear the TIF_RESTORE_TM bit since after the reclaim * the thread will no longer be transactional. */ if (test_ti_thread_flag(ti, TIF_RESTORE_TM)) { msr_diff = thr->tm_orig_msr & ~thr->regs->msr; if (msr_diff & MSR_FP) memcpy(&thr->transact_fp, &thr->fp_state, sizeof(struct thread_fp_state)); if (msr_diff & MSR_VEC) memcpy(&thr->transact_vr, &thr->vr_state, sizeof(struct thread_vr_state)); clear_ti_thread_flag(ti, TIF_RESTORE_TM); msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1; } tm_reclaim(thr, thr->regs->msr, cause); /* Having done the reclaim, we now have the checkpointed * FP/VSX values in the registers. These might be valid * even if we have previously called enable_kernel_fp() or * flush_fp_to_thread(), so update thr->regs->msr to * indicate their current validity. */ thr->regs->msr |= msr_diff; } void tm_reclaim_current(uint8_t cause) { tm_enable(); tm_reclaim_thread(¤t->thread, current_thread_info(), 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 and saves the transactional * (current) FPRs into oldtask->thread.transact_fpr[]. * * 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; /* Stash the original thread MSR, as giveup_fpu et al will * modify it. We hold onto it to see whether the task used * FP & vector regs. If the TIF_RESTORE_TM flag is set, * tm_orig_msr is already set. */ if (!test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_TM)) thr->tm_orig_msr = thr->regs->msr; 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, task_thread_info(tsk), 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, unsigned long orig_msr); void tm_recheckpoint(struct thread_struct *thread, unsigned long orig_msr) { unsigned long flags; /* 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, orig_msr); local_irq_restore(flags); } static inline void tm_recheckpoint_new_task(struct task_struct *new) { unsigned long msr; 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 * unavoidable later, we are unable to determine which set of FP regs * need to be restored. */ if (!new->thread.regs) return; if (!MSR_TM_ACTIVE(new->thread.regs->msr)){ tm_restore_sprs(&new->thread); return; } msr = new->thread.tm_orig_msr; /* Recheckpoint to restore original checkpointed register state. */ TM_DEBUG("*** tm_recheckpoint of pid %d " "(new->msr 0x%lx, new->origmsr 0x%lx)\n", new->pid, new->thread.regs->msr, msr); /* This loads the checkpointed FP/VEC state, if used */ tm_recheckpoint(&new->thread, msr); /* This loads the speculative FP/VEC state, if used */ if (msr & MSR_FP) { do_load_up_transact_fpu(&new->thread); new->thread.regs->msr |= (MSR_FP | new->thread.fpexc_mode); } #ifdef CONFIG_ALTIVEC if (msr & MSR_VEC) { do_load_up_transact_altivec(&new->thread); new->thread.regs->msr |= MSR_VEC; } #endif /* We may as well turn on VSX too since all the state is restored now */ if (msr & MSR_VSX) new->thread.regs->msr |= 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) { if (cpu_has_feature(CPU_FTR_TM)) { tm_enable(); tm_reclaim_task(prev); } } /* * 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; clear_thread_flag(TIF_RESTORE_TM); if (!MSR_TM_ACTIVE(regs->msr)) return; msr_diff = current->thread.tm_orig_msr & ~regs->msr; msr_diff &= MSR_FP | MSR_VEC | MSR_VSX; if (msr_diff & MSR_FP) { fp_enable(); load_fp_state(¤t->thread.fp_state); regs->msr |= current->thread.fpexc_mode; } if (msr_diff & MSR_VEC) { vec_enable(); load_vr_state(¤t->thread.vr_state); } regs->msr |= msr_diff; } #else #define tm_recheckpoint_new_task(new) #define __switch_to_tm(prev) #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ 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 WARN_ON(!irqs_disabled()); /* Back up the TAR and DSCR across context switches. * 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).) * Save the TAR and DSCR here before we do treclaim/trecheckpoint as * these will change them. */ save_early_sprs(&prev->thread); __switch_to_tm(prev); #ifdef CONFIG_SMP /* avoid complexity of lazy save/restore of fpu * by just saving it every time we switch out if * this task used the fpu during the last quantum. * * If it tries to use the fpu again, it'll trap and * reload its fp regs. So we don't have to do a restore * every switch, just a save. * -- Cort */ if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP)) giveup_fpu(prev); #ifdef CONFIG_ALTIVEC /* * If the previous thread used altivec in the last quantum * (thus changing altivec regs) then save them. * We used to check the VRSAVE register but not all apps * set it, so we don't rely on it now (and in fact we need * to save & restore VSCR even if VRSAVE == 0). -- paulus * * On SMP we always save/restore altivec regs just to avoid the * complexity of changing processors. * -- Cort */ if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) giveup_altivec(prev); #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_VSX if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX)) /* VMX and FPU registers are already save here */ __giveup_vsx(prev); #endif /* CONFIG_VSX */ #ifdef CONFIG_SPE /* * If the previous thread used spe in the last quantum * (thus changing spe regs) then save them. * * On SMP we always save/restore spe regs just to avoid the * complexity of changing processors. */ if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE))) giveup_spe(prev); #endif /* CONFIG_SPE */ #else /* CONFIG_SMP */ #ifdef CONFIG_ALTIVEC /* Avoid the trap. On smp this this never happens since * we don't set last_task_used_altivec -- Cort */ if (new->thread.regs && last_task_used_altivec == new) new->thread.regs->msr |= MSR_VEC; #endif /* CONFIG_ALTIVEC */ #ifdef CONFIG_VSX if (new->thread.regs && last_task_used_vsx == new) new->thread.regs->msr |= MSR_VSX; #endif /* CONFIG_VSX */ #ifdef CONFIG_SPE /* Avoid the trap. On smp this this never happens since * we don't set last_task_used_spe */ if (new->thread.regs && last_task_used_spe == new) new->thread.regs->msr |= MSR_SPE; #endif /* CONFIG_SPE */ #endif /* CONFIG_SMP */ #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 new_thread = &new->thread; old_thread = ¤t->thread; #ifdef CONFIG_PPC64 /* * Collect processor utilization data per process */ if (firmware_has_feature(FW_FEATURE_SPLPAR)) { struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array); long unsigned start_tb, current_tb; start_tb = old_thread->start_tb; cu->current_tb = current_tb = mfspr(SPRN_PURR); old_thread->accum_tb += (current_tb - start_tb); new_thread->start_tb = current_tb; } #endif /* CONFIG_PPC64 */ #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 */ /* * 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(); tm_recheckpoint_new_task(new); 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; } #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)) printk("\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)) { printk(KERN_CONT "XXXXXXXX "); } else { if (regs->nip == pc) printk(KERN_CONT "<%08x> ", instr); else printk(KERN_CONT "%08x ", instr); } pc += sizeof(int); } printk("\n"); } static struct regbit { unsigned long bit; const char *name; } 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 printbits(unsigned long val, struct regbit *bits) { const char *sep = ""; printk("<"); for (; bits->bit; ++bits) if (val & bits->bit) { printk("%s%s", sep, bits->name); sep = ","; } printk(">"); } #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: %p TRAP: %04lx %s (%s)\n", regs, regs->trap, print_tainted(), init_utsname()->release); printk("MSR: "REG" ", regs->msr); printbits(regs->msr, msr_bits); printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer); trap = TRAP(regs); if ((regs->trap != 0xc00) && cpu_has_feature(CPU_FTR_CFAR)) printk("CFAR: "REG" ", regs->orig_gpr3); if (trap == 0x200 || trap == 0x300 || trap == 0x600) #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) printk("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr); #else printk("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr); #endif #ifdef CONFIG_PPC64 printk("SOFTE: %ld ", regs->softe); #endif #ifdef CONFIG_PPC_TRANSACTIONAL_MEM if (MSR_TM_ACTIVE(regs->msr)) printk("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch); #endif for (i = 0; i < 32; i++) { if ((i % REGS_PER_LINE) == 0) printk("\nGPR%02d: ", i); printk(REG " ", regs->gpr[i]); if (i == LAST_VOLATILE && !FULL_REGS(regs)) break; } printk("\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 exit_thread(void) { discard_lazy_cpu_state(); } void flush_thread(void) { discard_lazy_cpu_state(); #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 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_fp_to_thread(src); flush_altivec_to_thread(src); flush_vsx_to_thread(src); flush_spe_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. */ __switch_to_tm(src); tm_recheckpoint_new_task(src); *dst = *src; clear_task_ebb(dst); return 0; } static void setup_ksp_vsid(struct task_struct *p, unsigned long sp) { #ifdef CONFIG_PPC_STD_MMU_64 unsigned long sp_vsid; unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; 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.. */ extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */ int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long 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; /* Copy registers */ sp -= sizeof(struct pt_regs); childregs = (struct pt_regs *) sp; if (unlikely(p->flags & PF_KTHREAD)) { struct thread_info *ti = (void *)task_stack_page(p); 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 = 1; #endif childregs->gpr[15] = arg; p->thread.regs = NULL; /* no user register state */ ti->flags |= _TIF_RESTOREALL; f = ret_from_kernel_thread; } else { 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; } 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 = current->thread.dscr; } if (cpu_has_feature(CPU_FTR_HAS_PPR)) p->thread.ppr = INIT_PPR; #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; } 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 discard_lazy_cpu_state(); #ifdef CONFIG_VSX current->thread.used_vsr = 0; #endif 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; #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 if (cpu_has_feature(CPU_FTR_TM)) regs->msr |= MSR_TM; current->thread.tm_tfhar = 0; current->thread.tm_texasr = 0; current->thread.tm_tfiar = 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) { #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). 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). 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 = *(unsigned long *)sp; if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) return 0; if (count > 0) { ip = ((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; unsigned long mrth = -1; #ifdef CONFIG_PPC64 extern void mod_return_to_handler(void); rth = *(unsigned long *)rth; mrth = (unsigned long)mod_return_to_handler; mrth = *(unsigned long *)mrth; #endif #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 || ip == mrth) && curr_frame >= 0) { printk(" (%pS)", (void *)current->ret_stack[curr_frame].ret); curr_frame--; } #endif if (firstframe) printk(" (unreliable)"); printk("\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(); unsigned long ctrl; 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(); unsigned long ctrl; ti->local_flags &= ~_TLF_RUNLATCH; 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 = (long)(get_random_int() % (1<<(23-PAGE_SHIFT))); else rnd = (long)(get_random_int() % (1<<(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_STD_MMU_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. */ 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; } unsigned long randomize_et_dyn(unsigned long base) { unsigned long ret = PAGE_ALIGN(base + brk_rnd()); if (ret < base) return base; return ret; }