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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [arch/] [m68knommu/] [kernel/] [ptrace.c] - Rev 1775
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/* * linux/arch/m68knommu/kernel/ptrace.c * * Copyright (C) 1998 D. Jeff Dionne <jeff@ryeham.ee.ryerson.ca>, * Kenneth Albanowski <kjahds@kjahds.com>, * The Silver Hammer Group, Ltd. * * Based on: * * linux/arch/m68k/kernel/ptrace * * Copyright (C) 1994 by Hamish Macdonald * Taken from linux/kernel/ptrace.c and modified for M680x0. * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds * * This file is subject to the terms and conditions of the GNU General * Public License. See the file COPYING in the main directory of * this archive for more details. */ #include <stddef.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/errno.h> #include <linux/ptrace.h> #include <linux/user.h> #include <asm/segment.h> #include <asm/page.h> #include <asm/pgtable.h> #include <asm/system.h> /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. */ /* determines which bits in the SR the user has access to. */ /* 1 = access 0 = no access */ #define SR_MASK 0x001f /* sets the trace bits. */ #define TRACE_BITS 0x8000 /* Find the stack offset for a register, relative to tss.esp0. */ #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg) #define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \ - sizeof(struct switch_stack)) /* Mapping from PT_xxx to the stack offset at which the register is saved. Notice that usp has no stack-slot and needs to be treated specially (see get_reg/put_reg below). */ static int regoff[] = { PT_REG(d1), PT_REG(d2), PT_REG(d3), PT_REG(d4), PT_REG(d5), SW_REG(d6), SW_REG(d7), PT_REG(a0), PT_REG(a1), SW_REG(a2), SW_REG(a3), SW_REG(a4), SW_REG(a5), SW_REG(a6), PT_REG(d0), -1, PT_REG(orig_d0), PT_REG(sr), PT_REG(pc), }; /* change a pid into a task struct. */ static inline struct task_struct * get_task(int pid) { int i; for (i = 1; i < NR_TASKS; i++) { if (task[i] != NULL && (task[i]->pid == pid)) return task[i]; } return NULL; } /* * Get contents of register REGNO in task TASK. */ static inline long get_reg(struct task_struct *task, int regno) { unsigned long *addr; if (regno == PT_USP) addr = &task->tss.usp; else if (regno < sizeof(regoff)/sizeof(regoff[0])) addr = (unsigned long *)(task->tss.esp0 + regoff[regno]); else return 0; return *addr; } /* * Write contents of register REGNO in task TASK. */ static inline int put_reg(struct task_struct *task, int regno, unsigned long data) { unsigned long *addr; if (regno == PT_USP) addr = &task->tss.usp; else if (regno < sizeof(regoff)/sizeof(regoff[0])) addr = (unsigned long *) (task->tss.esp0 + regoff[regno]); else return -1; *addr = data; return 0; } inline static unsigned long get_long(struct task_struct * tsk, struct vm_area_struct * vma, unsigned long addr) { return *(unsigned long*)addr; } inline static void put_long(struct task_struct * tsk, struct vm_area_struct * vma, unsigned long addr, unsigned long data) { *(unsigned long*)addr = data; } inline static int read_long(struct task_struct * tsk, unsigned long addr, unsigned long * result) { *result = *(unsigned long *)addr; return 0; } inline static int write_long(struct task_struct * tsk, unsigned long addr, unsigned long data) { *(unsigned long *)addr = data; return 0; } asmlinkage int sys_ptrace(long request, long pid, long addr, long data) { struct task_struct *child; struct user * dummy; dummy = NULL; if (request == PTRACE_TRACEME) { /* are we already being traced? */ if (current->flags & PF_PTRACED) return -EPERM; /* set the ptrace bit in the process flags. */ current->flags |= PF_PTRACED; return 0; } if (pid == 1) /* you may not mess with init */ return -EPERM; if (!(child = get_task(pid))) return -ESRCH; if (request == PTRACE_ATTACH) { if (child == current) return -EPERM; if ((!child->dumpable || (current->uid != child->euid) || (current->uid != child->suid) || (current->uid != child->uid) || (current->gid != child->egid) || (current->gid != child->sgid) || (current->gid != child->gid)) && !suser()) return -EPERM; /* the same process cannot be attached many times */ if (child->flags & PF_PTRACED) return -EPERM; child->flags |= PF_PTRACED; if (child->p_pptr != current) { REMOVE_LINKS(child); child->p_pptr = current; SET_LINKS(child); } send_sig(SIGSTOP, child, 1); return 0; } if (!(child->flags & PF_PTRACED)) return -ESRCH; if (child->state != TASK_STOPPED) { if (request != PTRACE_KILL) return -ESRCH; } if (child->p_pptr != current) return -ESRCH; switch (request) { /* when I and D space are separate, these will need to be fixed. */ case PTRACE_PEEKTEXT: /* read word at location addr. */ case PTRACE_PEEKDATA: { unsigned long tmp; int res; res = read_long(child, addr, &tmp); if (res < 0) return res; res = verify_area(VERIFY_WRITE, (void *) data, sizeof(long)); if (!res) put_user(tmp, (unsigned long *) data); return res; } /* read the word at location addr in the USER area. */ case PTRACE_PEEKUSR: { unsigned long tmp; int res; if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) return -EIO; res = verify_area(VERIFY_WRITE, (void *) data, sizeof(long)); if (res) return res; tmp = 0; /* Default return condition */ addr = addr >> 2; /* temporary hack. */ if (addr < 19) { tmp = get_reg(child, addr); if (addr == PT_SR) tmp >>= 16; } else if (addr >= 21 && addr < 49) tmp = child->tss.fp[addr - 21]; else if (addr == 49) tmp = child->mm->start_code; else if (addr == 50) tmp = child->mm->start_data; else return -EIO; put_user(tmp,(unsigned long *) data); return 0; } /* when I and D space are separate, this will have to be fixed. */ case PTRACE_POKETEXT: /* write the word at location addr. */ case PTRACE_POKEDATA: return write_long(child,addr,data); case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) return -EIO; addr = addr >> 2; /* temporary hack. */ if (addr == PT_ORIG_D0) return -EIO; if (addr == PT_SR) { data &= SR_MASK; data <<= 16; data |= get_reg(child, PT_SR) & ~(SR_MASK << 16); } if (addr < 19) { if (put_reg(child, addr, data)) return -EIO; return 0; } if (addr >= 21 && addr < 48) { child->tss.fp[addr - 21] = data; return 0; } return -EIO; case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ case PTRACE_CONT: { /* restart after signal. */ long tmp; if ((unsigned long) data >= NSIG) return -EIO; if (request == PTRACE_SYSCALL) child->flags |= PF_TRACESYS; else child->flags &= ~PF_TRACESYS; child->exit_code = data; wake_up_process(child); /* make sure the single step bit is not set. */ tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); put_reg(child, PT_SR, tmp); return 0; } /* * make the child exit. Best I can do is send it a sigkill. * perhaps it should be put in the status that it wants to * exit. */ case PTRACE_KILL: { long tmp; if (child->state == TASK_ZOMBIE) /* already dead */ return 0; wake_up_process(child); child->exit_code = SIGKILL; /* make sure the single step bit is not set. */ tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); put_reg(child, PT_SR, tmp); return 0; } case PTRACE_SINGLESTEP: { /* set the trap flag. */ long tmp; if ((unsigned long) data >= NSIG) return -EIO; child->flags &= ~PF_TRACESYS; tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16); put_reg(child, PT_SR, tmp); wake_up_process(child); child->exit_code = data; /* give it a chance to run. */ return 0; } case PTRACE_DETACH: { /* detach a process that was attached. */ long tmp; if ((unsigned long) data >= NSIG) return -EIO; child->flags &= ~(PF_PTRACED|PF_TRACESYS); wake_up_process(child); child->exit_code = data; REMOVE_LINKS(child); child->p_pptr = child->p_opptr; SET_LINKS(child); /* make sure the single step bit is not set. */ tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); put_reg(child, PT_SR, tmp); return 0; } default: return -EIO; } } asmlinkage void syscall_trace(void) { if ((current->flags & (PF_PTRACED|PF_TRACESYS)) != (PF_PTRACED|PF_TRACESYS)) return; current->exit_code = SIGTRAP; current->state = TASK_STOPPED; notify_parent(current, SIGCHLD); schedule(); /* * this isn't the same as continuing with a signal, but it will do * for normal use. strace only continues with a signal if the * stopping signal is not SIGTRAP. -brl */ if (current->exit_code) current->signal |= (1 << (current->exit_code - 1)); current->exit_code = 0; return; }
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