| /* |
| * linux/arch/ppc64/kernel/process.c |
| * |
| * Derived from "arch/i386/kernel/process.c" |
| * Copyright (C) 1995 Linus Torvalds |
| * |
| * Updated and modified by Cort Dougan (cort@cs.nmt.edu) and |
| * Paul Mackerras (paulus@cs.anu.edu.au) |
| * |
| * PowerPC version |
| * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/config.h> |
| #include <linux/module.h> |
| #include <linux/errno.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/smp.h> |
| #include <linux/smp_lock.h> |
| #include <linux/stddef.h> |
| #include <linux/unistd.h> |
| #include <linux/slab.h> |
| #include <linux/user.h> |
| #include <linux/elf.h> |
| #include <linux/init.h> |
| #include <linux/init_task.h> |
| #include <linux/prctl.h> |
| #include <linux/ptrace.h> |
| #include <linux/kallsyms.h> |
| #include <linux/interrupt.h> |
| #include <linux/utsname.h> |
| #include <linux/kprobes.h> |
| |
| #include <asm/pgtable.h> |
| #include <asm/uaccess.h> |
| #include <asm/system.h> |
| #include <asm/io.h> |
| #include <asm/processor.h> |
| #include <asm/mmu.h> |
| #include <asm/mmu_context.h> |
| #include <asm/prom.h> |
| #include <asm/ppcdebug.h> |
| #include <asm/machdep.h> |
| #include <asm/iSeries/HvCallHpt.h> |
| #include <asm/cputable.h> |
| #include <asm/firmware.h> |
| #include <asm/sections.h> |
| #include <asm/tlbflush.h> |
| #include <asm/time.h> |
| |
| #ifndef CONFIG_SMP |
| struct task_struct *last_task_used_math = NULL; |
| struct task_struct *last_task_used_altivec = NULL; |
| #endif |
| |
| /* |
| * 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(current); |
| } |
| preempt_enable(); |
| } |
| } |
| |
| void enable_kernel_fp(void) |
| { |
| WARN_ON(preemptible()); |
| |
| #ifdef CONFIG_SMP |
| if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) |
| giveup_fpu(current); |
| else |
| giveup_fpu(NULL); /* just enables FP for kernel */ |
| #else |
| giveup_fpu(last_task_used_math); |
| #endif /* CONFIG_SMP */ |
| } |
| EXPORT_SYMBOL(enable_kernel_fp); |
| |
| int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs) |
| { |
| if (!tsk->thread.regs) |
| return 0; |
| flush_fp_to_thread(current); |
| |
| memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs)); |
| |
| return 1; |
| } |
| |
| #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(current); |
| else |
| giveup_altivec(NULL); /* just enables FP for kernel */ |
| #else |
| giveup_altivec(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(current); |
| } |
| preempt_enable(); |
| } |
| } |
| |
| int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs) |
| { |
| flush_altivec_to_thread(current); |
| memcpy(vrregs, ¤t->thread.vr[0], sizeof(*vrregs)); |
| return 1; |
| } |
| |
| #endif /* CONFIG_ALTIVEC */ |
| |
| DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); |
| |
| struct task_struct *__switch_to(struct task_struct *prev, |
| struct task_struct *new) |
| { |
| struct thread_struct *new_thread, *old_thread; |
| unsigned long flags; |
| struct task_struct *last; |
| |
| #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 (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) |
| giveup_altivec(prev); |
| #endif /* CONFIG_ALTIVEC */ |
| #endif /* CONFIG_SMP */ |
| |
| #if defined(CONFIG_ALTIVEC) && !defined(CONFIG_SMP) |
| /* 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 */ |
| |
| flush_tlb_pending(); |
| |
| new_thread = &new->thread; |
| old_thread = ¤t->thread; |
| |
| /* Collect purr utilization data per process and per processor |
| * wise purr is nothing but processor time base |
| */ |
| if (firmware_has_feature(FW_FEATURE_SPLPAR)) { |
| struct cpu_usage *cu = &__get_cpu_var(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; |
| } |
| |
| local_irq_save(flags); |
| last = _switch(old_thread, new_thread); |
| |
| local_irq_restore(flags); |
| |
| 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 (((REGION_ID(pc) != KERNEL_REGION_ID) && |
| (REGION_ID(pc) != VMALLOC_REGION_ID)) || |
| __get_user(instr, (unsigned int *)pc)) { |
| printk("XXXXXXXX "); |
| } else { |
| if (regs->nip == pc) |
| printk("<%08x> ", instr); |
| else |
| printk("%08x ", instr); |
| } |
| |
| pc += sizeof(int); |
| } |
| |
| printk("\n"); |
| } |
| |
| void show_regs(struct pt_regs * regs) |
| { |
| int i; |
| unsigned long trap; |
| |
| printk("NIP: %016lX XER: %08X LR: %016lX CTR: %016lX\n", |
| regs->nip, (unsigned int)regs->xer, regs->link, regs->ctr); |
| printk("REGS: %p TRAP: %04lx %s (%s)\n", |
| regs, regs->trap, print_tainted(), system_utsname.release); |
| printk("MSR: %016lx EE: %01x PR: %01x FP: %01x ME: %01x " |
| "IR/DR: %01x%01x CR: %08X\n", |
| regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0, |
| regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0, |
| regs->msr&MSR_IR ? 1 : 0, |
| regs->msr&MSR_DR ? 1 : 0, |
| (unsigned int)regs->ccr); |
| trap = TRAP(regs); |
| printk("DAR: %016lx DSISR: %016lx\n", regs->dar, regs->dsisr); |
| printk("TASK: %p[%d] '%s' THREAD: %p", |
| current, current->pid, current->comm, current->thread_info); |
| |
| #ifdef CONFIG_SMP |
| printk(" CPU: %d", smp_processor_id()); |
| #endif /* CONFIG_SMP */ |
| |
| for (i = 0; i < 32; i++) { |
| if ((i % 4) == 0) { |
| printk("\n" KERN_INFO "GPR%02d: ", i); |
| } |
| |
| printk("%016lX ", regs->gpr[i]); |
| if (i == 13 && !FULL_REGS(regs)) |
| break; |
| } |
| printk("\n"); |
| /* |
| * Lookup NIP late so we have the best change of getting the |
| * above info out without failing |
| */ |
| printk("NIP [%016lx] ", regs->nip); |
| print_symbol("%s\n", regs->nip); |
| printk("LR [%016lx] ", regs->link); |
| print_symbol("%s\n", regs->link); |
| show_stack(current, (unsigned long *)regs->gpr[1]); |
| if (!user_mode(regs)) |
| show_instructions(regs); |
| } |
| |
| void exit_thread(void) |
| { |
| kprobe_flush_task(current); |
| |
| #ifndef CONFIG_SMP |
| 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 */ |
| #endif /* CONFIG_SMP */ |
| } |
| |
| void flush_thread(void) |
| { |
| struct thread_info *t = current_thread_info(); |
| |
| kprobe_flush_task(current); |
| if (t->flags & _TIF_ABI_PENDING) |
| t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT); |
| |
| #ifndef CONFIG_SMP |
| 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 */ |
| #endif /* CONFIG_SMP */ |
| } |
| |
| void |
| release_thread(struct task_struct *t) |
| { |
| } |
| |
| |
| /* |
| * This gets called before we allocate a new thread and copy |
| * the current task into it. |
| */ |
| void prepare_to_copy(struct task_struct *tsk) |
| { |
| flush_fp_to_thread(current); |
| flush_altivec_to_thread(current); |
| } |
| |
| /* |
| * Copy a thread.. |
| */ |
| int |
| copy_thread(int nr, unsigned long clone_flags, unsigned long usp, |
| unsigned long unused, struct task_struct *p, struct pt_regs *regs) |
| { |
| struct pt_regs *childregs, *kregs; |
| extern void ret_from_fork(void); |
| unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE; |
| |
| /* Copy registers */ |
| sp -= sizeof(struct pt_regs); |
| childregs = (struct pt_regs *) sp; |
| *childregs = *regs; |
| if ((childregs->msr & MSR_PR) == 0) { |
| /* for kernel thread, set stackptr in new task */ |
| childregs->gpr[1] = sp + sizeof(struct pt_regs); |
| p->thread.regs = NULL; /* no user register state */ |
| clear_ti_thread_flag(p->thread_info, TIF_32BIT); |
| } else { |
| childregs->gpr[1] = usp; |
| p->thread.regs = childregs; |
| if (clone_flags & CLONE_SETTLS) { |
| if (test_thread_flag(TIF_32BIT)) |
| childregs->gpr[2] = childregs->gpr[6]; |
| else |
| childregs->gpr[13] = childregs->gpr[6]; |
| } |
| } |
| childregs->gpr[3] = 0; /* Result 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. |
| */ |
| sp -= sizeof(struct pt_regs); |
| kregs = (struct pt_regs *) sp; |
| sp -= STACK_FRAME_OVERHEAD; |
| p->thread.ksp = sp; |
| if (cpu_has_feature(CPU_FTR_SLB)) { |
| unsigned long sp_vsid = get_kernel_vsid(sp); |
| |
| sp_vsid <<= SLB_VSID_SHIFT; |
| sp_vsid |= SLB_VSID_KERNEL; |
| if (cpu_has_feature(CPU_FTR_16M_PAGE)) |
| sp_vsid |= SLB_VSID_L; |
| |
| p->thread.ksp_vsid = sp_vsid; |
| } |
| |
| /* |
| * The PPC64 ABI makes use of a TOC to contain function |
| * pointers. The function (ret_from_except) is actually a pointer |
| * to the TOC entry. The first entry is a pointer to the actual |
| * function. |
| */ |
| kregs->nip = *((unsigned long *)ret_from_fork); |
| |
| return 0; |
| } |
| |
| /* |
| * Set up a thread for executing a new program |
| */ |
| void start_thread(struct pt_regs *regs, unsigned long fdptr, unsigned long sp) |
| { |
| unsigned long entry, toc, load_addr = regs->gpr[2]; |
| |
| /* fdptr 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. |
| */ |
| set_fs(USER_DS); |
| __get_user(entry, (unsigned long __user *)fdptr); |
| __get_user(toc, (unsigned long __user *)fdptr+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; |
| } |
| |
| /* |
| * If we exec out of a kernel thread then thread.regs will not be |
| * set. Do it now. |
| */ |
| if (!current->thread.regs) { |
| unsigned long childregs = (unsigned long)current->thread_info + |
| THREAD_SIZE; |
| childregs -= sizeof(struct pt_regs); |
| current->thread.regs = (struct pt_regs *)childregs; |
| } |
| |
| regs->nip = entry; |
| regs->gpr[1] = sp; |
| regs->gpr[2] = toc; |
| regs->msr = MSR_USER64; |
| #ifndef CONFIG_SMP |
| if (last_task_used_math == current) |
| last_task_used_math = 0; |
| #endif /* CONFIG_SMP */ |
| memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); |
| current->thread.fpscr = 0; |
| #ifdef CONFIG_ALTIVEC |
| #ifndef CONFIG_SMP |
| if (last_task_used_altivec == current) |
| last_task_used_altivec = 0; |
| #endif /* CONFIG_SMP */ |
| memset(current->thread.vr, 0, sizeof(current->thread.vr)); |
| current->thread.vscr.u[0] = 0; |
| current->thread.vscr.u[1] = 0; |
| current->thread.vscr.u[2] = 0; |
| current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */ |
| current->thread.vrsave = 0; |
| current->thread.used_vr = 0; |
| #endif /* CONFIG_ALTIVEC */ |
| } |
| EXPORT_SYMBOL(start_thread); |
| |
| int set_fpexc_mode(struct task_struct *tsk, unsigned int val) |
| { |
| struct pt_regs *regs = tsk->thread.regs; |
| |
| 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; |
| |
| val = __unpack_fe01(tsk->thread.fpexc_mode); |
| return put_user(val, (unsigned int __user *) adr); |
| } |
| |
| int sys_clone(unsigned long clone_flags, unsigned long p2, unsigned long p3, |
| unsigned long p4, unsigned long p5, unsigned long p6, |
| struct pt_regs *regs) |
| { |
| unsigned long parent_tidptr = 0; |
| unsigned long child_tidptr = 0; |
| |
| if (p2 == 0) |
| p2 = regs->gpr[1]; /* stack pointer for child */ |
| |
| if (clone_flags & (CLONE_PARENT_SETTID | CLONE_CHILD_SETTID | |
| CLONE_CHILD_CLEARTID)) { |
| parent_tidptr = p3; |
| child_tidptr = p5; |
| if (test_thread_flag(TIF_32BIT)) { |
| parent_tidptr &= 0xffffffff; |
| child_tidptr &= 0xffffffff; |
| } |
| } |
| |
| return do_fork(clone_flags, p2, regs, 0, |
| (int __user *)parent_tidptr, (int __user *)child_tidptr); |
| } |
| |
| int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3, |
| unsigned long p4, unsigned long p5, unsigned long p6, |
| struct pt_regs *regs) |
| { |
| return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL); |
| } |
| |
| int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3, |
| unsigned long p4, unsigned long p5, unsigned long p6, |
| struct pt_regs *regs) |
| { |
| return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1], regs, 0, |
| NULL, NULL); |
| } |
| |
| int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2, |
| unsigned long a3, unsigned long a4, unsigned long a5, |
| struct pt_regs *regs) |
| { |
| int error; |
| char * filename; |
| |
| filename = getname((char __user *) a0); |
| error = PTR_ERR(filename); |
| if (IS_ERR(filename)) |
| goto out; |
| flush_fp_to_thread(current); |
| flush_altivec_to_thread(current); |
| error = do_execve(filename, (char __user * __user *) a1, |
| (char __user * __user *) a2, regs); |
| |
| if (error == 0) { |
| task_lock(current); |
| current->ptrace &= ~PT_DTRACE; |
| task_unlock(current); |
| } |
| putname(filename); |
| |
| out: |
| return error; |
| } |
| |
| static int kstack_depth_to_print = 64; |
| |
| static int validate_sp(unsigned long sp, struct task_struct *p, |
| unsigned long nbytes) |
| { |
| unsigned long stack_page = (unsigned long)p->thread_info; |
| |
| if (sp >= stack_page + sizeof(struct thread_struct) |
| && sp <= stack_page + THREAD_SIZE - nbytes) |
| return 1; |
| |
| #ifdef CONFIG_IRQSTACKS |
| stack_page = (unsigned long) hardirq_ctx[task_cpu(p)]; |
| if (sp >= stack_page + sizeof(struct thread_struct) |
| && sp <= stack_page + THREAD_SIZE - nbytes) |
| return 1; |
| |
| stack_page = (unsigned long) softirq_ctx[task_cpu(p)]; |
| if (sp >= stack_page + sizeof(struct thread_struct) |
| && sp <= stack_page + THREAD_SIZE - nbytes) |
| return 1; |
| #endif |
| |
| return 0; |
| } |
| |
| 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, 112)) |
| return 0; |
| |
| do { |
| sp = *(unsigned long *)sp; |
| if (!validate_sp(sp, p, 112)) |
| return 0; |
| if (count > 0) { |
| ip = *(unsigned long *)(sp + 16); |
| if (!in_sched_functions(ip)) |
| return ip; |
| } |
| } while (count++ < 16); |
| return 0; |
| } |
| EXPORT_SYMBOL(get_wchan); |
| |
| void show_stack(struct task_struct *p, unsigned long *_sp) |
| { |
| unsigned long ip, newsp, lr; |
| int count = 0; |
| unsigned long sp = (unsigned long)_sp; |
| int firstframe = 1; |
| |
| if (sp == 0) { |
| if (p) { |
| sp = p->thread.ksp; |
| } else { |
| sp = __get_SP(); |
| p = current; |
| } |
| } |
| |
| lr = 0; |
| printk("Call Trace:\n"); |
| do { |
| if (!validate_sp(sp, p, 112)) |
| return; |
| |
| _sp = (unsigned long *) sp; |
| newsp = _sp[0]; |
| ip = _sp[2]; |
| if (!firstframe || ip != lr) { |
| printk("[%016lx] [%016lx] ", sp, ip); |
| print_symbol("%s", ip); |
| 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, p, sizeof(struct pt_regs) + 400) |
| && _sp[12] == 0x7265677368657265ul) { |
| struct pt_regs *regs = (struct pt_regs *) |
| (sp + STACK_FRAME_OVERHEAD); |
| printk("--- Exception: %lx", regs->trap); |
| print_symbol(" at %s\n", regs->nip); |
| lr = regs->link; |
| print_symbol(" LR = %s\n", lr); |
| firstframe = 1; |
| } |
| |
| sp = newsp; |
| } while (count++ < kstack_depth_to_print); |
| } |
| |
| void dump_stack(void) |
| { |
| show_stack(current, (unsigned long *)__get_SP()); |
| } |
| EXPORT_SYMBOL(dump_stack); |