diff options
Diffstat (limited to 'arch/powerpc/kernel/process.c')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 919 |
1 files changed, 919 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c new file mode 100644 index 00000000000..8f85dabe4df --- /dev/null +++ b/arch/powerpc/kernel/process.c @@ -0,0 +1,919 @@ +/* + * arch/ppc/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/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/ptrace.h> +#include <linux/slab.h> +#include <linux/user.h> +#include <linux/elf.h> +#include <linux/init.h> +#include <linux/prctl.h> +#include <linux/init_task.h> +#include <linux/module.h> +#include <linux/kallsyms.h> +#include <linux/mqueue.h> +#include <linux/hardirq.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/prom.h> +#ifdef CONFIG_PPC64 +#include <asm/firmware.h> +#include <asm/plpar_wrappers.h> +#include <asm/time.h> +#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_spe = 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 enable AltiVec for kernel - force */ +#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 */ + +#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 + giveup_spe(current); + } + preempt_enable(); + } +} + +int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs) +{ + flush_spe_to_thread(current); + /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */ + memcpy(evrregs, ¤t->thread.evr[0], sizeof(u32) * 35); + return 1; +} +#endif /* CONFIG_SPE */ + +static void set_dabr_spr(unsigned long val) +{ + mtspr(SPRN_DABR, val); +} + +int set_dabr(unsigned long dabr) +{ + int ret = 0; + +#ifdef CONFIG_PPC64 + if (firmware_has_feature(FW_FEATURE_XDABR)) { + /* We want to catch accesses from kernel and userspace */ + unsigned long flags = H_DABRX_KERNEL|H_DABRX_USER; + ret = plpar_set_xdabr(dabr, flags); + } else if (firmware_has_feature(FW_FEATURE_DABR)) { + ret = plpar_set_dabr(dabr); + } else +#endif + set_dabr_spr(dabr); + + return ret; +} + +#ifdef CONFIG_PPC64 +DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); +static DEFINE_PER_CPU(unsigned long, current_dabr); +#endif + +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 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_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_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_PPC64 /* for now */ + if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) { + set_dabr(new->thread.dabr); + __get_cpu_var(current_dabr) = new->thread.dabr; + } + + flush_tlb_pending(); +#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 = &__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; + } +#endif + + local_irq_save(flags); + last = _switch(old_thread, new_thread); + + local_irq_restore(flags); + + return last; +} + +static int instructions_to_print = 16; + +#ifdef CONFIG_PPC64 +#define BAD_PC(pc) ((REGION_ID(pc) != KERNEL_REGION_ID) && \ + (REGION_ID(pc) != VMALLOC_REGION_ID)) +#else +#define BAD_PC(pc) ((pc) < KERNELBASE) +#endif + +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 (BAD_PC(pc) || __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"); +} + +static struct regbit { + unsigned long bit; + const char *name; +} msr_bits[] = { + {MSR_EE, "EE"}, + {MSR_PR, "PR"}, + {MSR_FP, "FP"}, + {MSR_ME, "ME"}, + {MSR_IR, "IR"}, + {MSR_DR, "DR"}, + {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; + + 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(), system_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 (trap == 0x300 || trap == 0x600) + printk("DAR: "REG", DSISR: "REG"\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 % REGS_PER_LINE) == 0) + printk("\n" KERN_INFO "GPR%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"] ", regs->nip); + print_symbol("%s\n", regs->nip); + printk("LR ["REG"] ", regs->link); + print_symbol("%s\n", regs->link); +#endif + 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 */ +#ifdef CONFIG_SPE + if (last_task_used_spe == current) + last_task_used_spe = NULL; +#endif +#endif /* CONFIG_SMP */ +} + +void flush_thread(void) +{ +#ifdef CONFIG_PPC64 + struct thread_info *t = current_thread_info(); + + if (t->flags & _TIF_ABI_PENDING) + t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT); +#endif + 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 */ +#ifdef CONFIG_SPE + if (last_task_used_spe == current) + last_task_used_spe = NULL; +#endif +#endif /* CONFIG_SMP */ + +#ifdef CONFIG_PPC64 /* for now */ + if (current->thread.dabr) { + current->thread.dabr = 0; + set_dabr(0); + } +#endif +} + +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); + flush_spe_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; + + CHECK_FULL_REGS(regs); + /* Copy registers */ + sp -= sizeof(struct pt_regs); + childregs = (struct pt_regs *) sp; + *childregs = *regs; + if ((childregs->msr & MSR_PR) == 0) { + /* for kernel thread, set `current' and stackptr in new task */ + childregs->gpr[1] = sp + sizeof(struct pt_regs); +#ifdef CONFIG_PPC32 + childregs->gpr[2] = (unsigned long) p; +#else + clear_ti_thread_flag(p->thread_info, TIF_32BIT); +#endif + p->thread.regs = NULL; /* no user register state */ + } else { + childregs->gpr[1] = usp; + p->thread.regs = childregs; + if (clone_flags & CLONE_SETTLS) { +#ifdef CONFIG_PPC64 + if (!test_thread_flag(TIF_32BIT)) + childregs->gpr[13] = childregs->gpr[6]; + else +#endif + childregs->gpr[2] = 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; + +#ifdef CONFIG_PPC64 + 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); +#else + kregs->nip = (unsigned long)ret_from_fork; + p->thread.last_syscall = -1; +#endif + + 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 + + set_fs(USER_DS); + + /* + * 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; + } + + memset(regs->gpr, 0, sizeof(regs->gpr)); + regs->ctr = 0; + regs->link = 0; + regs->xer = 0; + regs->ccr = 0; + regs->gpr[1] = sp; + +#ifdef CONFIG_PPC32 + regs->mq = 0; + regs->nip = start; + regs->msr = MSR_USER; +#else + if (!test_thread_flag(TIF_32BIT)) { + unsigned long entry, 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->nip = entry; + regs->gpr[2] = toc; + regs->msr = MSR_USER64; + } else { + regs->nip = start; + regs->gpr[2] = 0; + regs->msr = MSR_USER32; + } +#endif + +#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 +#ifdef CONFIG_SPE + if (last_task_used_spe == current) + last_task_used_spe = NULL; +#endif +#endif /* CONFIG_SMP */ + memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); + current->thread.fpscr.val = 0; +#ifdef CONFIG_ALTIVEC + memset(current->thread.vr, 0, sizeof(current->thread.vr)); + memset(¤t->thread.vscr, 0, sizeof(current->thread.vscr)); + current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */ + 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 */ +} + +#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 + tsk->thread.fpexc_mode = val & + (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); + return 0; +#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 + val = tsk->thread.fpexc_mode; +#else + return -EINVAL; +#endif + else + val = __unpack_fe01(tsk->thread.fpexc_mode); + return put_user(val, (unsigned int __user *) adr); +} + +#define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff)) + +int sys_clone(unsigned long clone_flags, unsigned long usp, + int __user *parent_tidp, void __user *child_threadptr, + int __user *child_tidp, int p6, + struct pt_regs *regs) +{ + CHECK_FULL_REGS(regs); + if (usp == 0) + usp = regs->gpr[1]; /* stack pointer for child */ +#ifdef CONFIG_PPC64 + if (test_thread_flag(TIF_32BIT)) { + parent_tidp = TRUNC_PTR(parent_tidp); + child_tidp = TRUNC_PTR(child_tidp); + } +#endif + return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp); +} + +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) +{ + CHECK_FULL_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) +{ + CHECK_FULL_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); + flush_spe_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 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; +} + +#ifdef CONFIG_PPC64 +#define MIN_STACK_FRAME 112 /* same as STACK_FRAME_OVERHEAD, in fact */ +#define FRAME_LR_SAVE 2 +#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288) +#define REGS_MARKER 0x7265677368657265ul +#define FRAME_MARKER 12 +#else +#define MIN_STACK_FRAME 16 +#define FRAME_LR_SAVE 1 +#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) +#define REGS_MARKER 0x72656773ul +#define FRAME_MARKER 2 +#endif + +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, MIN_STACK_FRAME)) + return 0; + + do { + sp = *(unsigned long *)sp; + if (!validate_sp(sp, p, MIN_STACK_FRAME)) + return 0; + if (count > 0) { + ip = ((unsigned long *)sp)[FRAME_LR_SAVE]; + if (!in_sched_functions(ip)) + return ip; + } + } while (count++ < 16); + return 0; +} +EXPORT_SYMBOL(get_wchan); + +static int kstack_depth_to_print = 64; + +void show_stack(struct task_struct *tsk, unsigned long *stack) +{ + unsigned long sp, ip, lr, newsp; + int count = 0; + int firstframe = 1; + + sp = (unsigned long) stack; + if (tsk == NULL) + tsk = current; + if (sp == 0) { + if (tsk == current) + asm("mr %0,1" : "=r" (sp)); + else + sp = tsk->thread.ksp; + } + + lr = 0; + printk("Call Trace:\n"); + do { + if (!validate_sp(sp, tsk, MIN_STACK_FRAME)) + return; + + stack = (unsigned long *) sp; + newsp = stack[0]; + ip = stack[FRAME_LR_SAVE]; + if (!firstframe || ip != lr) { + printk("["REG"] ["REG"] ", 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, tsk, INT_FRAME_SIZE) + && stack[FRAME_MARKER] == REGS_MARKER) { + 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, NULL); +} +EXPORT_SYMBOL(dump_stack); |