diff options
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 911 |
1 files changed, 560 insertions, 351 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 7bb7faf84490..a45fe147868b 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -34,17 +34,15 @@ #include <linux/ftrace.h> #include <linux/kernel_stat.h> #include <linux/personality.h> -#include <linux/random.h> #include <linux/hw_breakpoint.h> #include <linux/uaccess.h> -#include <linux/elf-randomize.h> #include <linux/pkeys.h> #include <linux/seq_buf.h> +#include <asm/interrupt.h> #include <asm/io.h> #include <asm/processor.h> #include <asm/mmu.h> -#include <asm/prom.h> #include <asm/machdep.h> #include <asm/time.h> #include <asm/runlatch.h> @@ -56,7 +54,7 @@ #include <asm/firmware.h> #include <asm/hw_irq.h> #endif -#include <asm/code-patching.h> +#include <asm/text-patching.h> #include <asm/exec.h> #include <asm/livepatch.h> #include <asm/cpu_has_feature.h> @@ -74,8 +72,6 @@ #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 @@ -95,7 +91,8 @@ static void check_if_tm_restore_required(struct task_struct *tsk) if (tsk == current && tsk->thread.regs && MSR_TM_ACTIVE(tsk->thread.regs->msr) && !test_thread_flag(TIF_RESTORE_TM)) { - tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr; + regs_set_return_msr(&tsk->thread.ckpt_regs, + tsk->thread.regs->msr); set_thread_flag(TIF_RESTORE_TM); } } @@ -124,13 +121,11 @@ unsigned long notrace msr_check_and_set(unsigned long bits) newmsr = oldmsr | bits; -#ifdef CONFIG_VSX if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP)) newmsr |= MSR_VSX; -#endif if (oldmsr != newmsr) - mtmsr_isync(newmsr); + newmsr = mtmsr_isync_irqsafe(newmsr); return newmsr; } @@ -144,13 +139,11 @@ void notrace __msr_check_and_clear(unsigned long bits) newmsr = oldmsr & ~bits; -#ifdef CONFIG_VSX if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP)) newmsr &= ~MSR_VSX; -#endif if (oldmsr != newmsr) - mtmsr_isync(newmsr); + mtmsr_isync_irqsafe(newmsr); } EXPORT_SYMBOL(__msr_check_and_clear); @@ -162,11 +155,9 @@ static void __giveup_fpu(struct task_struct *tsk) save_fpu(tsk); msr = tsk->thread.regs->msr; msr &= ~(MSR_FP|MSR_FE0|MSR_FE1); -#ifdef CONFIG_VSX if (cpu_has_feature(CPU_FTR_VSX)) msr &= ~MSR_VSX; -#endif - tsk->thread.regs->msr = msr; + regs_set_return_msr(tsk->thread.regs, msr); } void giveup_fpu(struct task_struct *tsk) @@ -235,6 +226,8 @@ void enable_kernel_fp(void) } } EXPORT_SYMBOL(enable_kernel_fp); +#else +static inline void __giveup_fpu(struct task_struct *tsk) { } #endif /* CONFIG_PPC_FPU */ #ifdef CONFIG_ALTIVEC @@ -245,11 +238,9 @@ static void __giveup_altivec(struct task_struct *tsk) save_altivec(tsk); msr = tsk->thread.regs->msr; msr &= ~MSR_VEC; -#ifdef CONFIG_VSX if (cpu_has_feature(CPU_FTR_VSX)) msr &= ~MSR_VSX; -#endif - tsk->thread.regs->msr = msr; + regs_set_return_msr(tsk->thread.regs, msr); } void giveup_altivec(struct task_struct *tsk) @@ -311,7 +302,7 @@ static void __giveup_vsx(struct task_struct *tsk) unsigned long msr = tsk->thread.regs->msr; /* - * We should never be ssetting MSR_VSX without also setting + * 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))); @@ -414,21 +405,14 @@ static unsigned long msr_all_available; static int __init init_msr_all_available(void) { -#ifdef CONFIG_PPC_FPU - msr_all_available |= MSR_FP; -#endif -#ifdef CONFIG_ALTIVEC + if (IS_ENABLED(CONFIG_PPC_FPU)) + msr_all_available |= MSR_FP; if (cpu_has_feature(CPU_FTR_ALTIVEC)) msr_all_available |= MSR_VEC; -#endif -#ifdef CONFIG_VSX if (cpu_has_feature(CPU_FTR_VSX)) msr_all_available |= MSR_VSX; -#endif -#ifdef CONFIG_SPE if (cpu_has_feature(CPU_FTR_SPE)) msr_all_available |= MSR_SPE; -#endif return 0; } @@ -452,18 +436,12 @@ void giveup_all(struct task_struct *tsk) WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC))); -#ifdef CONFIG_PPC_FPU if (usermsr & MSR_FP) __giveup_fpu(tsk); -#endif -#ifdef CONFIG_ALTIVEC if (usermsr & MSR_VEC) __giveup_altivec(tsk); -#endif -#ifdef CONFIG_SPE if (usermsr & MSR_SPE) __giveup_spe(tsk); -#endif msr_check_and_clear(msr_all_available); } @@ -471,49 +449,57 @@ EXPORT_SYMBOL(giveup_all); #ifdef CONFIG_PPC_BOOK3S_64 #ifdef CONFIG_PPC_FPU -static int restore_fp(struct task_struct *tsk) +static bool should_restore_fp(void) { - if (tsk->thread.load_fp) { - load_fp_state(¤t->thread.fp_state); + if (current->thread.load_fp) { current->thread.load_fp++; - return 1; + return true; } - return 0; + return false; +} + +static void do_restore_fp(void) +{ + load_fp_state(¤t->thread.fp_state); } #else -static int restore_fp(struct task_struct *tsk) { return 0; } +static bool should_restore_fp(void) { return false; } +static void do_restore_fp(void) { } #endif /* CONFIG_PPC_FPU */ #ifdef CONFIG_ALTIVEC -#define loadvec(thr) ((thr).load_vec) -static int restore_altivec(struct task_struct *tsk) +static bool should_restore_altivec(void) { - if (cpu_has_feature(CPU_FTR_ALTIVEC) && (tsk->thread.load_vec)) { - load_vr_state(&tsk->thread.vr_state); - tsk->thread.used_vr = 1; - tsk->thread.load_vec++; - - return 1; + if (cpu_has_feature(CPU_FTR_ALTIVEC) && (current->thread.load_vec)) { + current->thread.load_vec++; + return true; } - return 0; + return false; +} + +static void do_restore_altivec(void) +{ + load_vr_state(¤t->thread.vr_state); + current->thread.used_vr = 1; } #else -#define loadvec(thr) 0 -static inline int restore_altivec(struct task_struct *tsk) { return 0; } +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 int restore_vsx(struct task_struct *tsk) +static void do_restore_vsx(void) { - if (cpu_has_feature(CPU_FTR_VSX)) { - tsk->thread.used_vsr = 1; - return 1; - } - - return 0; + current->thread.used_vsr = 1; } #else -static inline int restore_vsx(struct task_struct *tsk) { return 0; } +static void do_restore_vsx(void) { } #endif /* CONFIG_VSX */ /* @@ -529,34 +515,50 @@ static inline int restore_vsx(struct task_struct *tsk) { return 0; } void notrace restore_math(struct pt_regs *regs) { unsigned long msr; - - if (!MSR_TM_ACTIVE(regs->msr) && - !current->thread.load_fp && !loadvec(current->thread)) - return; + unsigned long new_msr = 0; msr = regs->msr; - msr_check_and_set(msr_all_available); /* - * Only reload if the bit is not set in the user MSR, the bit BEING set - * indicates that the registers are hot + * 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)) && restore_fp(current)) - msr |= MSR_FP | current->thread.fpexc_mode; + if ((!(msr & MSR_FP)) && should_restore_fp()) + new_msr |= MSR_FP; - if ((!(msr & MSR_VEC)) && restore_altivec(current)) - msr |= MSR_VEC; + if ((!(msr & MSR_VEC)) && should_restore_altivec()) + new_msr |= MSR_VEC; - if ((msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC) && - restore_vsx(current)) { - msr |= MSR_VSX; + if ((!(msr & MSR_VSX)) && should_restore_vsx()) { + if (((msr | new_msr) & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC)) + new_msr |= MSR_VSX; } - msr_check_and_clear(msr_all_available); + 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(); - regs->msr = msr; + 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 +#endif /* CONFIG_PPC_BOOK3S_64 */ static void save_all(struct task_struct *tsk) { @@ -584,7 +586,6 @@ static void save_all(struct task_struct *tsk) __giveup_spe(tsk); msr_check_and_clear(msr_all_available); - thread_pkey_regs_save(&tsk->thread); } void flush_all_to_thread(struct task_struct *tsk) @@ -617,19 +618,66 @@ void do_send_trap(struct pt_regs *regs, unsigned long address, (void __user *)address); } #else /* !CONFIG_PPC_ADV_DEBUG_REGS */ -void do_break (struct pt_regs *regs, unsigned long address, - unsigned long error_code) + +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, error_code, + 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 *)address); + force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar); } #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ @@ -754,30 +802,6 @@ static void switch_hw_breakpoint(struct task_struct *new) #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; @@ -788,7 +812,19 @@ static inline int set_dabr(struct arch_hw_breakpoint *brk) if (ppc_md.set_dabr) return ppc_md.set_dabr(dabr, dabrx); - return __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) @@ -824,10 +860,8 @@ static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk) return 0; } -void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk) +static void set_hw_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); @@ -841,6 +875,12 @@ void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk) WARN_ON_ONCE(1); } +void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk) +{ + memcpy(this_cpu_ptr(¤t_brk[nr]), brk, sizeof(*brk)); + set_hw_breakpoint(nr, brk); +} + /* Check if we have DAWR or DABR hardware */ bool ppc_breakpoint_available(void) { @@ -853,6 +893,34 @@ bool ppc_breakpoint_available(void) } EXPORT_SYMBOL_GPL(ppc_breakpoint_available); +/* Disable the breakpoint in hardware without touching current_brk[] */ +void suspend_breakpoints(void) +{ + struct arch_hw_breakpoint brk = {0}; + int i; + + if (!ppc_breakpoint_available()) + return; + + for (i = 0; i < nr_wp_slots(); i++) + set_hw_breakpoint(i, &brk); +} + +/* + * Re-enable breakpoints suspended by suspend_breakpoints() in hardware + * from current_brk[] + */ +void restore_breakpoints(void) +{ + int i; + + if (!ppc_breakpoint_available()) + return; + + for (i = 0; i < nr_wp_slots(); i++) + set_hw_breakpoint(i, this_cpu_ptr(¤t_brk[i])); +} + #ifdef CONFIG_PPC_TRANSACTIONAL_MEM static inline bool tm_enabled(struct task_struct *tsk) @@ -932,7 +1000,7 @@ static inline void tm_reclaim_task(struct task_struct *tsk) WARN_ON(tm_suspend_disabled); - TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, " + 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, @@ -940,7 +1008,7 @@ static inline void tm_reclaim_task(struct task_struct *tsk) tm_reclaim_thread(thr, TM_CAUSE_RESCHED); - TM_DEBUG("--- tm_reclaim on pid %d complete\n", + TM_DEBUG("---- tm_reclaim on pid %d complete\n", tsk->pid); out_and_saveregs: @@ -1074,12 +1142,13 @@ void restore_tm_state(struct pt_regs *regs) #endif restore_math(regs); - regs->msr |= msr_diff; + regs_set_return_msr(regs, regs->msr | msr_diff); } -#else +#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) @@ -1088,6 +1157,10 @@ static inline void save_sprs(struct thread_struct *t) 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); @@ -1107,10 +1180,48 @@ static inline void save_sprs(struct thread_struct *t) */ t->tar = mfspr(SPRN_TAR); } + + if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE)) + t->hashkeyr = mfspr(SPRN_HASHKEYR); + + if (cpu_has_feature(CPU_FTR_ARCH_31)) + t->dexcr = mfspr(SPRN_DEXCR); +#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); - thread_pkey_regs_save(t); +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) @@ -1120,6 +1231,11 @@ static inline void restore_sprs(struct thread_struct *old_thread, 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; @@ -1148,9 +1264,16 @@ static inline void restore_sprs(struct thread_struct *old_thread, if (cpu_has_feature(CPU_FTR_P9_TIDR) && old_thread->tidr != new_thread->tidr) mtspr(SPRN_TIDR, new_thread->tidr); + + if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE) && + old_thread->hashkeyr != new_thread->hashkeyr) + mtspr(SPRN_HASHKEYR, new_thread->hashkeyr); + + if (cpu_has_feature(CPU_FTR_ARCH_31) && + old_thread->dexcr != new_thread->dexcr) + mtspr(SPRN_DEXCR, new_thread->dexcr); #endif - thread_pkey_regs_restore(new_thread, old_thread); } struct task_struct *__switch_to(struct task_struct *prev, @@ -1158,7 +1281,7 @@ struct task_struct *__switch_to(struct task_struct *prev, { struct thread_struct *new_thread, *old_thread; struct task_struct *last; -#ifdef CONFIG_PPC_BOOK3S_64 +#ifdef CONFIG_PPC_64S_HASH_MMU struct ppc64_tlb_batch *batch; #endif @@ -1167,7 +1290,7 @@ struct task_struct *__switch_to(struct task_struct *prev, WARN_ON(!irqs_disabled()); -#ifdef CONFIG_PPC_BOOK3S_64 +#ifdef CONFIG_PPC_64S_HASH_MMU batch = this_cpu_ptr(&ppc64_tlb_batch); if (batch->active) { current_thread_info()->local_flags |= _TLF_LAZY_MMU; @@ -1175,6 +1298,19 @@ struct task_struct *__switch_to(struct task_struct *prev, __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 @@ -1210,38 +1346,50 @@ struct task_struct *__switch_to(struct task_struct *prev, } /* - * Call restore_sprs() before calling _switch(). If we move it after - * _switch() then we miss out on calling it for new tasks. The reason - * for this is we manually create a stack frame for new tasks that - * directly returns through ret_from_fork() or + * 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 - if (current->thread.regs) { + /* + * 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); - - /* - * The copy-paste buffer can only store into foreign real - * addresses, so unprivileged processes can not see the - * data or use it in any way unless they have foreign real - * mappings. If the new process has the foreign real address - * mappings, we must issue a cp_abort to clear any state and - * prevent snooping, corruption or a covert channel. - */ - if (current->mm && - atomic_read(¤t->mm->context.vas_windows)) - asm volatile(PPC_CP_ABORT); - } #endif /* CONFIG_PPC_BOOK3S_64 */ return last; @@ -1252,29 +1400,27 @@ struct task_struct *__switch_to(struct task_struct *prev, 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:"); + printk("Code: "); + + /* + * 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 !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((const void *)pc, instr)) { + if (get_kernel_nofault(instr, (const void *)pc)) { pr_cont("XXXXXXXX "); } else { - if (regs->nip == pc) + if (nip == pc) pr_cont("<%08x> ", instr); else pr_cont("%08x ", instr); @@ -1305,7 +1451,8 @@ void show_user_instructions(struct pt_regs *regs) for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) { int instr; - if (probe_user_read(&instr, (void __user *)pc, sizeof(instr))) { + if (copy_from_user_nofault(&instr, (void __user *)pc, + sizeof(instr))) { seq_buf_printf(&s, "XXXXXXXX "); continue; } @@ -1402,19 +1549,15 @@ static void print_msr_bits(unsigned long val) #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) +static void __show_regs(struct pt_regs *regs) { int i, trap; - show_regs_print_info(KERN_DEFAULT); - printk("NIP: "REG" LR: "REG" CTR: "REG"\n", regs->nip, regs->link, regs->ctr); printk("REGS: %px TRAP: %04lx %s (%s)\n", @@ -1425,12 +1568,15 @@ void show_regs(struct pt_regs * regs) trap = TRAP(regs); if (!trap_is_syscall(regs) && cpu_has_feature(CPU_FTR_CFAR)) pr_cont("CFAR: "REG" ", regs->orig_gpr3); - if (trap == 0x200 || trap == 0x300 || trap == 0x600) -#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) - pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr); -#else - pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr); -#endif + if (trap == INTERRUPT_MACHINE_CHECK || + trap == INTERRUPT_DATA_STORAGE || + trap == INTERRUPT_ALIGNMENT) { + if (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 @@ -1443,18 +1589,22 @@ void show_regs(struct pt_regs * regs) if ((i % REGS_PER_LINE) == 0) pr_cont("\nGPR%02d: ", i); pr_cont(REG " ", regs->gpr[i]); - if (i == LAST_VOLATILE && !FULL_REGS(regs)) - break; } pr_cont("\n"); -#ifdef CONFIG_KALLSYMS /* * Lookup NIP late so we have the best change of getting the * above info out without failing */ - printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip); - printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link); -#endif + 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); @@ -1469,17 +1619,37 @@ void flush_thread(void) #endif /* CONFIG_HAVE_HW_BREAKPOINT */ } -#ifdef CONFIG_PPC_BOOK3S_64 void arch_setup_new_exec(void) { - if (radix_enabled()) - return; - hash__setup_new_exec(); -} + +#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_PPC_BOOK3S_64 + if (cpu_has_feature(CPU_FTR_ARCH_31)) { + current->thread.dexcr = current->thread.dexcr_onexec; + mtspr(SPRN_DEXCR, current->thread.dexcr); + } +#endif /* CONFIG_PPC_BOOK3S_64 */ +} #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. * @@ -1489,7 +1659,7 @@ void arch_setup_new_exec(void) * 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 + * In this situation, the correct thread is woken and proceeds to pass its * condition check. * * 2. Neither threads are running @@ -1499,15 +1669,15 @@ void arch_setup_new_exec(void) * 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 + * The wrong thread will be woken, but will fail its 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 + * its condition check (which will pass), or wait, which returns immediately + * when called the first time after the thread is scheduled, followed by its * 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 + * Both threads will be woken. The wrong thread will fail its condition check + * and execute another wait, while the correct thread will pass its condition * check. * * @t: the task to set the thread ID for @@ -1532,11 +1702,6 @@ EXPORT_SYMBOL_GPL(set_thread_tidr); #endif /* CONFIG_PPC64 */ -void -release_thread(struct task_struct *t) -{ -} - /* * this gets called so that we can store coprocessor state into memory and * copy the current task into the new thread. @@ -1565,7 +1730,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) static void setup_ksp_vsid(struct task_struct *p, unsigned long sp) { -#ifdef CONFIG_PPC_BOOK3S_64 +#ifdef CONFIG_PPC_64S_HASH_MMU unsigned long sp_vsid; unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; @@ -1590,60 +1755,85 @@ static void setup_ksp_vsid(struct task_struct *p, unsigned long sp) /* * Copy architecture-specific thread state */ -int copy_thread_tls(unsigned long clone_flags, unsigned long usp, - unsigned long kthread_arg, struct task_struct *p, - unsigned long tls) +int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) { - struct pt_regs *childregs, *kregs; + struct pt_regs *kregs; /* Switch frame regs */ extern void ret_from_fork(void); - extern void ret_from_kernel_thread(void); + extern void ret_from_fork_scv(void); + extern void ret_from_kernel_user_thread(void); + extern void start_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(p->flags & PF_KTHREAD)) { /* kernel thread */ - memset(childregs, 0, sizeof(struct pt_regs)); - childregs->gpr[1] = sp + sizeof(struct pt_regs); - /* function */ - if (usp) - childregs->gpr[14] = ppc_function_entry((void *)usp); -#ifdef CONFIG_PPC64 - clear_tsk_thread_flag(p, TIF_32BIT); - childregs->softe = IRQS_ENABLED; -#endif - childregs->gpr[15] = kthread_arg; + + /* Create initial minimum stack frame. */ + sp -= STACK_FRAME_MIN_SIZE; + ((unsigned long *)sp)[0] = 0; + + f = start_kernel_thread; p->thread.regs = NULL; /* no user register state */ - ti->flags |= _TIF_RESTOREALL; - f = ret_from_kernel_thread; + clear_tsk_compat_task(p); } else { /* user thread */ - struct pt_regs *regs = current_pt_regs(); - CHECK_FULL_REGS(regs); - *childregs = *regs; - if (usp) - childregs->gpr[1] = usp; - p->thread.regs = childregs; - childregs->gpr[3] = 0; /* Result from fork() */ - if (clone_flags & CLONE_SETTLS) { - if (!is_32bit_task()) - childregs->gpr[13] = tls; + struct pt_regs *childregs; + + /* Create initial user return stack frame. */ + sp -= STACK_USER_INT_FRAME_SIZE; + *(unsigned long *)(sp + STACK_INT_FRAME_MARKER) = STACK_FRAME_REGS_MARKER; + + childregs = (struct pt_regs *)(sp + STACK_INT_FRAME_REGS); + + if (unlikely(args->fn)) { + /* + * A user space thread, but it first runs a kernel + * thread, and then returns as though it had called + * execve rather than fork, so user regs will be + * filled in (e.g., by kernel_execve()). + */ + ((unsigned long *)sp)[0] = 0; + memset(childregs, 0, sizeof(struct pt_regs)); +#ifdef CONFIG_PPC64 + childregs->softe = IRQS_ENABLED; +#endif + f = ret_from_kernel_user_thread; + } else { + struct pt_regs *regs = current_pt_regs(); + u64 clone_flags = args->flags; + unsigned long usp = args->stack; + + /* Copy registers */ + *childregs = *regs; + if (usp) + childregs->gpr[1] = usp; + ((unsigned long *)sp)[0] = childregs->gpr[1]; +#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG + WARN_ON_ONCE(childregs->softe != IRQS_ENABLED); +#endif + if (clone_flags & CLONE_SETTLS) { + unsigned long tls = args->tls; + + if (!is_32bit_task()) + childregs->gpr[13] = tls; + else + childregs->gpr[2] = tls; + } + + if (trap_is_scv(regs)) + f = ret_from_fork_scv; else - childregs->gpr[2] = tls; + f = ret_from_fork; } - f = ret_from_fork; + childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX); + p->thread.regs = childregs; } - childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX); - sp -= STACK_FRAME_OVERHEAD; /* * The way this works is that at some point in the future @@ -1653,23 +1843,39 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp, * 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; + ((unsigned long *)sp)[STACK_FRAME_LR_SAVE] = (unsigned long)f; + sp -= STACK_SWITCH_FRAME_SIZE; + ((unsigned long *)sp)[0] = sp + STACK_SWITCH_FRAME_SIZE; + kregs = (struct pt_regs *)(sp + STACK_SWITCH_FRAME_REGS); + kregs->nip = ppc_function_entry(f); + if (unlikely(args->fn)) { + /* + * Put kthread fn, arg parameters in non-volatile GPRs in the + * switch frame so they are loaded by _switch before it returns + * to ret_from_kernel_thread. + */ + kregs->gpr[14] = ppc_function_entry((void *)args->fn); + kregs->gpr[15] = (unsigned long)args->fn_arg; + } p->thread.ksp = sp; -#ifdef CONFIG_PPC32 - p->thread.ksp_limit = (unsigned long)end_of_stack(p); -#endif + #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) && defined(CONFIG_PPC_KUAP) + p->thread.pid = MMU_NO_CONTEXT; +#endif setup_ksp_vsid(p, sp); @@ -1678,17 +1884,19 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp, 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 - kregs->nip = ppc_function_entry(f); +#ifdef CONFIG_PPC_BOOK3S_64 + if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE)) + p->thread.hashkeyr = current->thread.hashkeyr; + + if (cpu_has_feature(CPU_FTR_ARCH_31)) + p->thread.dexcr = mfspr(SPRN_DEXCR); +#endif return 0; } -void preload_new_slb_context(unsigned long start, unsigned long sp); - /* * Set up a thread for executing a new program */ @@ -1696,22 +1904,8 @@ 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 */ - -#ifdef CONFIG_PPC_BOOK3S_64 - if (!radix_enabled()) - preload_new_slb_context(start, sp); -#endif #endif - /* - * If we exec out of a kernel thread then thread.regs will not be - * set. Do it now. - */ - if (!current->thread.regs) { - struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; - current->thread.regs = regs - 1; - } - #ifdef CONFIG_PPC_TRANSACTIONAL_MEM /* * Clear any transactional state, we're exec()ing. The cause is @@ -1722,20 +1916,13 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) tm_reclaim_current(0); #endif - memset(regs->gpr, 0, sizeof(regs->gpr)); + 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; - /* - * 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. - */ - SET_FULL_REGS(regs); - #ifdef CONFIG_PPC32 regs->mq = 0; regs->nip = start; @@ -1768,8 +1955,8 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) * 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); + 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. @@ -1780,21 +1967,24 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) } regs->gpr[2] = toc; } - regs->nip = entry; - regs->msr = MSR_USER64; + regs_set_return_ip(regs, entry); + regs_set_return_msr(regs, MSR_USER64); } else { - regs->nip = start; regs->gpr[2] = 0; - regs->msr = MSR_USER32; + 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 */ @@ -1815,8 +2005,12 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) current->thread.tm_tfiar = 0; current->thread.load_tm = 0; #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ - - thread_pkey_regs_init(¤t->thread); +#ifdef CONFIG_PPC_BOOK3S_64 + if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE)) { + current->thread.hashkeyr = get_random_long(); + mtspr(SPRN_HASHKEYR, current->thread.hashkeyr); + } +#endif /* CONFIG_PPC_BOOK3S_64 */ } EXPORT_SYMBOL(start_thread); @@ -1832,7 +2026,6 @@ int set_fpexc_mode(struct task_struct *tsk, unsigned int val) * 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 @@ -1846,16 +2039,15 @@ int set_fpexc_mode(struct task_struct *tsk, unsigned int val) * 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; } -#else - return -EINVAL; -#endif } /* on a CONFIG_SPE this does not hurt us. The bits that @@ -1866,18 +2058,18 @@ int set_fpexc_mode(struct task_struct *tsk, unsigned int val) 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; + 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; + unsigned int val = 0; - if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) -#ifdef CONFIG_SPE + if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) { if (cpu_has_feature(CPU_FTR_SPE)) { /* * When the sticky exception bits are set @@ -1891,15 +2083,15 @@ int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) * 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 - return -EINVAL; -#endif - else + } else { val = __unpack_fe01(tsk->thread.fpexc_mode); + } return put_user(val, (unsigned int __user *) adr); } @@ -1915,9 +2107,9 @@ int set_endian(struct task_struct *tsk, unsigned int val) return -EINVAL; if (val == PR_ENDIAN_BIG) - regs->msr &= ~MSR_LE; + regs_set_return_msr(regs, regs->msr & ~MSR_LE); else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) - regs->msr |= MSR_LE; + regs_set_return_msr(regs, regs->msr | MSR_LE); else return -EINVAL; @@ -1964,6 +2156,9 @@ static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, unsigned long stack_page; unsigned long cpu = task_cpu(p); + if (!hardirq_ctx[cpu] || !softirq_ctx[cpu]) + return 0; + stack_page = (unsigned long)hardirq_ctx[cpu]; if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) return 1; @@ -1975,13 +2170,24 @@ static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, return 0; } +#ifdef CONFIG_PPC64 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; + + if (!paca_ptrs[cpu]->emergency_sp) + return 0; + +# ifdef CONFIG_PPC_BOOK3S_64 + if (!paca_ptrs[cpu]->nmi_emergency_sp || !paca_ptrs[cpu]->mc_emergency_sp) + return 0; +#endif + stack_page = (unsigned long)paca_ptrs[cpu]->emergency_sp - THREAD_SIZE; if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) return 1; @@ -1995,14 +2201,33 @@ static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p, if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) return 1; # endif -#endif return 0; } +#else +static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p, + unsigned long nbytes) +{ + unsigned long stack_page; + unsigned long cpu = task_cpu(p); + if (!IS_ENABLED(CONFIG_VMAP_STACK)) + return 0; -int validate_sp(unsigned long sp, struct task_struct *p, - unsigned long nbytes) + stack_page = (unsigned long)emergency_ctx[cpu] - THREAD_SIZE; + if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) + return 1; + + return 0; +} +#endif + +/* + * validate the stack frame of a particular minimum size, used for when we are + * looking at a certain object in the stack beyond the minimum. + */ +int validate_sp_size(unsigned long sp, struct task_struct *p, + unsigned long nbytes) { unsigned long stack_page = (unsigned long)task_stack_page(p); @@ -2018,27 +2243,26 @@ int validate_sp(unsigned long sp, struct task_struct *p, return valid_emergency_stack(sp, p, nbytes); } -EXPORT_SYMBOL(validate_sp); +int validate_sp(unsigned long sp, struct task_struct *p) +{ + return validate_sp_size(sp, p, STACK_FRAME_MIN_SIZE); +} -static unsigned long __get_wchan(struct task_struct *p) +static 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)) + if (!validate_sp(sp, p)) return 0; do { - sp = *(unsigned long *)sp; - if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) || - p->state == TASK_RUNNING) + sp = READ_ONCE_NOCHECK(*(unsigned long *)sp); + if (!validate_sp(sp, p) || task_is_running(p)) return 0; if (count > 0) { - ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE]; + ip = READ_ONCE_NOCHECK(((unsigned long *)sp)[STACK_FRAME_LR_SAVE]); if (!in_sched_functions(ip)) return ip; } @@ -2046,32 +2270,47 @@ static unsigned long __get_wchan(struct task_struct *p) return 0; } -unsigned long get_wchan(struct task_struct *p) +unsigned long __get_wchan(struct task_struct *p) { unsigned long ret; if (!try_get_task_stack(p)) return 0; - ret = __get_wchan(p); + ret = ___get_wchan(p); put_task_stack(p); return ret; } +static bool empty_user_regs(struct pt_regs *regs, struct task_struct *tsk) +{ + unsigned long stack_page; + + // A non-empty pt_regs should never have a zero MSR or TRAP value. + if (regs->msr || regs->trap) + return false; + + // Check it sits at the very base of the stack + stack_page = (unsigned long)task_stack_page(tsk); + if ((unsigned long)(regs + 1) != stack_page + THREAD_SIZE) + return false; + + return true; +} + static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; -void show_stack(struct task_struct *tsk, unsigned long *stack, - const char *loglvl) +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; -#ifdef CONFIG_FUNCTION_GRAPH_TRACER unsigned long ret_addr; int ftrace_idx = 0; -#endif if (tsk == NULL) tsk = current; @@ -2090,7 +2329,7 @@ void show_stack(struct task_struct *tsk, unsigned long *stack, lr = 0; printk("%sCall Trace:\n", loglvl); do { - if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) + if (!validate_sp(sp, tsk)) break; stack = (unsigned long *) sp; @@ -2099,12 +2338,10 @@ void show_stack(struct task_struct *tsk, unsigned long *stack, if (!firstframe || ip != lr) { printk("%s["REG"] ["REG"] %pS", loglvl, sp, ip, (void *)ip); -#ifdef CONFIG_FUNCTION_GRAPH_TRACER ret_addr = ftrace_graph_ret_addr(current, &ftrace_idx, ip, stack); if (ret_addr != ip) pr_cont(" (%pS)", (void *)ret_addr); -#endif if (firstframe) pr_cont(" (unreliable)"); pr_cont("\n"); @@ -2113,16 +2350,28 @@ void show_stack(struct task_struct *tsk, unsigned long *stack, /* * See if this is an exception frame. - * We look for the "regshere" marker in the current frame. + * We look for the "regs" marker in the current frame. + * + * STACK_SWITCH_FRAME_SIZE being the smallest frame that + * could hold a pt_regs, if that does not fit then it can't + * have regs. */ - if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) - && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { + if (validate_sp_size(sp, tsk, STACK_SWITCH_FRAME_SIZE) + && stack[STACK_INT_FRAME_MARKER_LONGS] == STACK_FRAME_REGS_MARKER) { struct pt_regs *regs = (struct pt_regs *) - (sp + STACK_FRAME_OVERHEAD); + (sp + STACK_INT_FRAME_REGS); + lr = regs->link; - printk("%s--- interrupt: %lx at %pS\n LR = %pS\n", - loglvl, regs->trap, - (void *)regs->nip, (void *)lr); + printk("%s---- interrupt: %lx at %pS\n", + loglvl, regs->trap, (void *)regs->nip); + + // Detect the case of an empty pt_regs at the very base + // of the stack and suppress showing it in full. + if (!empty_user_regs(regs, tsk)) { + __show_regs(regs); + printk("%s---- interrupt: %lx\n", loglvl, regs->trap); + } + firstframe = 1; } @@ -2182,46 +2431,6 @@ void notrace __ppc64_runlatch_off(void) unsigned long arch_align_stack(unsigned long sp) { if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) - sp -= get_random_int() & ~PAGE_MASK; + sp -= get_random_u32_below(PAGE_SIZE); return sp & ~0xf; } - -static inline unsigned long brk_rnd(void) -{ - unsigned long rnd = 0; - - /* 8MB for 32bit, 1GB for 64bit */ - if (is_32bit_task()) - rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT))); - else - rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT))); - - return rnd << PAGE_SHIFT; -} - -unsigned long arch_randomize_brk(struct mm_struct *mm) -{ - unsigned long base = mm->brk; - unsigned long ret; - -#ifdef CONFIG_PPC_BOOK3S_64 - /* - * If we are using 1TB segments and we are allowed to randomise - * the heap, we can put it above 1TB so it is backed by a 1TB - * segment. Otherwise the heap will be in the bottom 1TB - * which always uses 256MB segments and this may result in a - * performance penalty. We don't need to worry about radix. For - * radix, mmu_highuser_ssize remains unchanged from 256MB. - */ - if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T)) - base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T); -#endif - - ret = PAGE_ALIGN(base + brk_rnd()); - - if (ret < mm->brk) - return mm->brk; - - return ret; -} - |