| /* |
| * linux/arch/cris/kernel/ptrace.c |
| * |
| * Parts taken from the m68k port. |
| * |
| * Copyright (c) 2000, 2001 Axis Communications AB |
| * |
| * Authors: Bjorn Wesen |
| * |
| * $Log: ptrace.c,v $ |
| * Revision 1.2 2001/12/18 13:35:20 bjornw |
| * Applied the 2.4.13->2.4.16 CRIS patch to 2.5.1 (is a copy of 2.4.15). |
| * |
| * Revision 1.8 2001/11/12 18:26:21 pkj |
| * Fixed compiler warnings. |
| * |
| * Revision 1.7 2001/09/26 11:53:49 bjornw |
| * PTRACE_DETACH works more simple in 2.4.10 |
| * |
| * Revision 1.6 2001/07/25 16:08:47 bjornw |
| * PTRACE_ATTACH bulk moved into arch-independant code in 2.4.7 |
| * |
| * Revision 1.5 2001/03/26 14:24:28 orjanf |
| * * Changed loop condition. |
| * * Added comment documenting non-standard ptrace behaviour. |
| * |
| * Revision 1.4 2001/03/20 19:44:41 bjornw |
| * Use the user_regs macro instead of thread.esp0 |
| * |
| * Revision 1.3 2000/12/18 23:45:25 bjornw |
| * Linux/CRIS first version |
| * |
| * |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/smp.h> |
| #include <linux/smp_lock.h> |
| #include <linux/errno.h> |
| #include <linux/ptrace.h> |
| #include <linux/user.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/page.h> |
| #include <asm/pgtable.h> |
| #include <asm/system.h> |
| #include <asm/processor.h> |
| |
| /* |
| * does not yet catch signals sent when the child dies. |
| * in exit.c or in signal.c. |
| */ |
| |
| /* determines which bits in DCCR the user has access to. */ |
| /* 1 = access 0 = no access */ |
| #define DCCR_MASK 0x0000001f /* XNZVC */ |
| |
| /* |
| * Get contents of register REGNO in task TASK. |
| */ |
| static inline long get_reg(struct task_struct *task, unsigned int regno) |
| { |
| /* USP is a special case, it's not in the pt_regs struct but |
| * in the tasks thread struct |
| */ |
| |
| if (regno == PT_USP) |
| return task->thread.usp; |
| else if (regno < PT_MAX) |
| return ((unsigned long *)user_regs(task))[regno]; |
| else |
| return 0; |
| } |
| |
| /* |
| * Write contents of register REGNO in task TASK. |
| */ |
| static inline int put_reg(struct task_struct *task, unsigned int regno, |
| unsigned long data) |
| { |
| if (regno == PT_USP) |
| task->thread.usp = data; |
| else if (regno < PT_MAX) |
| ((unsigned long *)user_regs(task))[regno] = data; |
| else |
| return -1; |
| return 0; |
| } |
| |
| /* |
| * Called by kernel/ptrace.c when detaching.. |
| * |
| * Make sure the single step bit is not set. |
| */ |
| void ptrace_disable(struct task_struct *child) |
| { |
| /* Todo - pending singlesteps? */ |
| } |
| |
| /* Note that this implementation of ptrace behaves differently from vanilla |
| * ptrace. Contrary to what the man page says, in the PTRACE_PEEKTEXT, |
| * PTRACE_PEEKDATA, and PTRACE_PEEKUSER requests the data variable is not |
| * ignored. Instead, the data variable is expected to point at a location |
| * (in user space) where the result of the ptrace call is written (instead of |
| * being returned). |
| */ |
| |
| asmlinkage int sys_ptrace(long request, long pid, long addr, long data) |
| { |
| struct task_struct *child; |
| int ret; |
| |
| lock_kernel(); |
| ret = -EPERM; |
| if (request == PTRACE_TRACEME) { |
| /* are we already being traced? */ |
| if (current->ptrace & PT_PTRACED) |
| goto out; |
| /* set the ptrace bit in the process flags. */ |
| current->ptrace |= PT_PTRACED; |
| ret = 0; |
| goto out; |
| } |
| ret = -ESRCH; |
| read_lock(&tasklist_lock); |
| child = find_task_by_pid(pid); |
| if (child) |
| get_task_struct(child); |
| read_unlock(&tasklist_lock); |
| if (!child) |
| goto out; |
| ret = -EPERM; |
| if (pid == 1) /* you may not mess with init */ |
| goto out_tsk; |
| if (request == PTRACE_ATTACH) { |
| ret = ptrace_attach(child); |
| goto out_tsk; |
| } |
| ret = -ESRCH; |
| if (!(child->ptrace & PT_PTRACED)) |
| goto out_tsk; |
| if (child->state != TASK_STOPPED) { |
| if (request != PTRACE_KILL) |
| goto out_tsk; |
| } |
| if (child->p_pptr != current) |
| goto out_tsk; |
| |
| 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 copied; |
| |
| copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); |
| ret = -EIO; |
| if (copied != sizeof(tmp)) |
| break; |
| ret = put_user(tmp,(unsigned long *) data); |
| break; |
| } |
| |
| /* read the word at location addr in the USER area. */ |
| case PTRACE_PEEKUSR: { |
| unsigned long tmp; |
| |
| ret = -EIO; |
| if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) |
| break; |
| |
| tmp = 0; /* Default return condition */ |
| ret = -EIO; |
| if (addr < sizeof(struct pt_regs)) { |
| tmp = get_reg(child, addr >> 2); |
| ret = put_user(tmp, (unsigned long *)data); |
| } |
| break; |
| } |
| |
| /* 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: |
| ret = 0; |
| if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) |
| break; |
| ret = -EIO; |
| break; |
| |
| case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ |
| ret = -EIO; |
| if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) |
| break; |
| |
| if (addr < sizeof(struct pt_regs)) { |
| addr >>= 2; |
| |
| if (addr == PT_DCCR) { |
| /* don't allow the tracing process to change stuff like |
| * interrupt enable, kernel/user bit, dma enables etc. |
| */ |
| data &= DCCR_MASK; |
| data |= get_reg(child, PT_DCCR) & ~DCCR_MASK; |
| } |
| if (put_reg(child, addr, data)) |
| break; |
| ret = 0; |
| } |
| break; |
| |
| case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ |
| case PTRACE_CONT: /* restart after signal. */ |
| ret = -EIO; |
| if ((unsigned long) data > _NSIG) |
| break; |
| if (request == PTRACE_SYSCALL) |
| child->ptrace |= PT_TRACESYS; |
| else |
| child->ptrace &= ~PT_TRACESYS; |
| child->exit_code = data; |
| /* TODO: make sure any pending breakpoint is killed */ |
| wake_up_process(child); |
| ret = 0; |
| break; |
| |
| /* |
| * 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: |
| ret = 0; |
| if (child->state == TASK_ZOMBIE) /* already dead */ |
| break; |
| child->exit_code = SIGKILL; |
| /* TODO: make sure any pending breakpoint is killed */ |
| wake_up_process(child); |
| break; |
| |
| case PTRACE_SINGLESTEP: /* set the trap flag. */ |
| ret = -EIO; |
| if ((unsigned long) data > _NSIG) |
| break; |
| child->ptrace &= ~PT_TRACESYS; |
| |
| /* TODO: set some clever breakpoint mechanism... */ |
| |
| child->exit_code = data; |
| /* give it a chance to run. */ |
| wake_up_process(child); |
| ret = 0; |
| break; |
| |
| case PTRACE_DETACH: |
| ret = ptrace_detach(child, data); |
| break; |
| |
| case PTRACE_GETREGS: { /* Get all gp regs from the child. */ |
| int i; |
| unsigned long tmp; |
| for (i = 0; i <= PT_MAX; i++) { |
| tmp = get_reg(child, i); |
| if (put_user(tmp, (unsigned long *) data)) { |
| ret = -EFAULT; |
| break; |
| } |
| data += sizeof(long); |
| } |
| ret = 0; |
| break; |
| } |
| |
| case PTRACE_SETREGS: { /* Set all gp regs in the child. */ |
| int i; |
| unsigned long tmp; |
| for (i = 0; i <= PT_MAX; i++) { |
| if (get_user(tmp, (unsigned long *) data)) { |
| ret = -EFAULT; |
| break; |
| } |
| if (i == PT_DCCR) { |
| tmp &= DCCR_MASK; |
| tmp |= get_reg(child, PT_DCCR) & ~DCCR_MASK; |
| } |
| put_reg(child, i, tmp); |
| data += sizeof(long); |
| } |
| ret = 0; |
| break; |
| } |
| |
| default: |
| ret = -EIO; |
| break; |
| } |
| out_tsk: |
| free_task_struct(child); |
| out: |
| unlock_kernel(); |
| return ret; |
| } |
| |
| asmlinkage void syscall_trace(void) |
| { |
| if ((current->ptrace & (PT_PTRACED | PT_TRACESYS)) != |
| (PT_PTRACED | PT_TRACESYS)) |
| return; |
| /* TODO: make a way to distinguish between a syscall stop and SIGTRAP |
| * delivery like in the i386 port ? |
| */ |
| 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) { |
| send_sig(current->exit_code, current, 1); |
| current->exit_code = 0; |
| } |
| } |