/* * 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. * * arch/sh64/kernel/ptrace.c * * Copyright (C) 2000, 2001 Paolo Alberelli * * Started from SH3/4 version: * SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka * * Original x86 implementation: * By Ross Biro 1/23/92 * edited by Linus Torvalds * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* This mask defines the bits of the SR which the user is not allowed to change, which are everything except S, Q, M, PR, SZ, FR. */ #define SR_MASK (0xffff8cfd) /* * does not yet catch signals sent when the child dies. * in exit.c or in signal.c. */ /* * This routine will get a word off of the process kernel stack. */ static inline int get_stack_long(struct task_struct *task, int offset) { unsigned char *stack; stack = (unsigned char *)(task->thread.kregs); stack += offset; return (*((int *)stack)); } static inline unsigned long get_fpu_long(struct task_struct *task, unsigned long addr) { unsigned long tmp; struct pt_regs *regs; regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1; if (!task->used_math) { if (addr == offsetof(struct user_fpu_struct, fpscr)) { tmp = FPSCR_INIT; } else { tmp = 0xffffffffUL; /* matches initial value in fpu.c */ } return tmp; } if (last_task_used_math == task) { grab_fpu(); fpsave(&task->thread.fpu.hard); release_fpu(); last_task_used_math = 0; regs->sr |= SR_FD; } tmp = ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)]; return tmp; } /* * This routine will put a word on the process kernel stack. */ static inline int put_stack_long(struct task_struct *task, int offset, unsigned long data) { unsigned char *stack; stack = (unsigned char *)(task->thread.kregs); stack += offset; *(unsigned long *) stack = data; return 0; } static inline int put_fpu_long(struct task_struct *task, unsigned long addr, unsigned long data) { struct pt_regs *regs; regs = (struct pt_regs*)((unsigned char *)task + THREAD_SIZE) - 1; if (!task->used_math) { fpinit(&task->thread.fpu.hard); task->used_math = 1; } else if (last_task_used_math == task) { grab_fpu(); fpsave(&task->thread.fpu.hard); release_fpu(); last_task_used_math = 0; regs->sr |= SR_FD; } ((long *)&task->thread.fpu)[addr / sizeof(unsigned long)] = data; return 0; } asmlinkage int sys_ptrace(long request, long pid, long addr, long data) { struct task_struct *child, *tsk = current; 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 != tsk) 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) break; if (addr < sizeof(struct pt_regs)) tmp = get_stack_long(child, addr); else if ((addr >= offsetof(struct user, fpu)) && (addr < offsetof(struct user, u_fpvalid))) { tmp = get_fpu_long(child, addr - offsetof(struct user, fpu)); } else if (addr == offsetof(struct user, u_fpvalid)) { tmp = child->used_math; } else { break; } 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. We must disallow any changes to certain SR bits or u_fpvalid, since this could crash the kernel or result in a security loophole. */ ret = -EIO; if ((addr & 3) || addr < 0) break; if (addr < sizeof(struct pt_regs)) { /* Ignore change of top 32 bits of SR */ if (addr == offsetof (struct pt_regs, sr)+4) { ret = 0; break; } /* If lower 32 bits of SR, ignore non-user bits */ if (addr == offsetof (struct pt_regs, sr)) { long cursr = get_stack_long(child, addr); data &= ~(SR_MASK); data |= (cursr & SR_MASK); } ret = put_stack_long(child, addr, data); } else if ((addr >= offsetof(struct user, fpu)) && (addr < offsetof(struct user, u_fpvalid))) { ret = put_fpu_long(child, addr - offsetof(struct user, fpu), data); } 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; 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; wake_up_process(child); break; } case PTRACE_SINGLESTEP: { /* set the trap flag. */ struct pt_regs *regs; ret = -EIO; if ((unsigned long) data > _NSIG) break; child->ptrace &= ~PT_TRACESYS; if ((child->ptrace & PT_DTRACE) == 0) { /* Spurious delayed TF traps may occur */ child->ptrace |= PT_DTRACE; } regs = child->thread.kregs; regs->sr |= SR_SSTEP; /* auto-resetting upon exception */ child->exit_code = data; /* give it a chance to run. */ wake_up_process(child); ret = 0; break; } case PTRACE_DETACH: /* detach a process that was attached. */ ret = ptrace_detach(child, data); break; case PTRACE_SETOPTIONS: { if (data & PTRACE_O_TRACESYSGOOD) child->ptrace |= PT_TRACESYSGOOD; else child->ptrace &= ~PT_TRACESYSGOOD; ret = 0; break; } default: ret = -EIO; break; } out_tsk: free_task_struct(child); out: unlock_kernel(); return ret; } asmlinkage void syscall_trace(void) { struct task_struct *tsk = current; if ((tsk->ptrace & (PT_PTRACED|PT_TRACESYS)) != (PT_PTRACED|PT_TRACESYS)) return; tsk->exit_code = SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0); tsk->state = TASK_STOPPED; notify_parent(tsk, 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 (tsk->exit_code) { send_sig(tsk->exit_code, tsk, 1); tsk->exit_code = 0; } } /* Called with interrupts disabled */ asmlinkage void do_single_step(unsigned long long vec, struct pt_regs *regs) { /* This is called after a single step exception (DEBUGSS). There is no need to change the PC, as it is a post-execution exception, as entry.S does not do anything to the PC for DEBUGSS. We need to clear the Single Step setting in SR to avoid continually stepping. */ __sti(); regs->sr &= ~SR_SSTEP; force_sig(SIGTRAP, current); } /* Called with interrupts disabled */ asmlinkage void do_software_break_point(unsigned long long vec, struct pt_regs *regs) { /* We need to forward step the PC, to counteract the backstep done in signal.c. */ __sti(); force_sig(SIGTRAP, current); regs->pc += 4; } /* * Called by kernel/ptrace.c when detaching.. * * Make sure single step bits etc are not set. */ void ptrace_disable(struct task_struct *child) { /* nothing to do.. */ }