/* * linux/arch/sh/kernel/ptrace.c * * Original x86 implementation: * By Ross Biro 1/23/92 * edited by Linus Torvalds * * SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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_pt_regs(task); stack += offset; return (*((int *)stack)); } /* * 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_pt_regs(task); stack += offset; *(unsigned long *) stack = data; return 0; } static void ptrace_disable_singlestep(struct task_struct *child) { clear_tsk_thread_flag(child, TIF_SINGLESTEP); /* * Ensure the UBC is not programmed at the next context switch. * * Normally this is not needed but there are sequences such as * singlestep, signal delivery, and continue that leave the * ubc_pc non-zero leading to spurious SIGTRAPs. */ if (child->thread.ubc_pc != 0) { ubc_usercnt -= 1; child->thread.ubc_pc = 0; } } /* * Called by kernel/ptrace.c when detaching.. * * Make sure single step bits etc are not set. */ void ptrace_disable(struct task_struct *child) { ptrace_disable_singlestep(child); } long arch_ptrace(struct task_struct *child, long request, long addr, long data) { struct user * dummy = NULL; int ret; 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: ret = generic_ptrace_peekdata(child, addr, data); /* 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) - 3) break; if (addr < sizeof(struct pt_regs)) tmp = get_stack_long(child, addr); else if (addr >= (long) &dummy->fpu && addr < (long) &dummy->u_fpvalid) { if (!tsk_used_math(child)) { if (addr == (long)&dummy->fpu.fpscr) tmp = FPSCR_INIT; else tmp = 0; } else tmp = ((long *)&child->thread.fpu) [(addr - (long)&dummy->fpu) >> 2]; } else if (addr == (long) &dummy->u_fpvalid) tmp = !!tsk_used_math(child); else tmp = 0; ret = put_user(tmp, (unsigned long __user *)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 = generic_ptrace_pokedata(child, addr, data); 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) - 3) break; if (addr < sizeof(struct pt_regs)) ret = put_stack_long(child, addr, data); else if (addr >= (long) &dummy->fpu && addr < (long) &dummy->u_fpvalid) { set_stopped_child_used_math(child); ((long *)&child->thread.fpu) [(addr - (long)&dummy->fpu) >> 2] = data; ret = 0; } else if (addr == (long) &dummy->u_fpvalid) { conditional_stopped_child_used_math(data, child); ret = 0; } break; case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ case PTRACE_CONT: { /* restart after signal. */ ret = -EIO; if (!valid_signal(data)) break; if (request == PTRACE_SYSCALL) set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); else clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); ptrace_disable_singlestep(child); 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->exit_state == EXIT_ZOMBIE) /* already dead */ break; ptrace_disable_singlestep(child); child->exit_code = SIGKILL; wake_up_process(child); break; } case PTRACE_SINGLESTEP: { /* set the trap flag. */ long pc; struct pt_regs *regs = NULL; ret = -EIO; if (!valid_signal(data)) break; clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); if ((child->ptrace & PT_DTRACE) == 0) { /* Spurious delayed TF traps may occur */ child->ptrace |= PT_DTRACE; } pc = get_stack_long(child, (long)®s->pc); /* Next scheduling will set up UBC */ if (child->thread.ubc_pc == 0) ubc_usercnt += 1; child->thread.ubc_pc = pc; set_tsk_thread_flag(child, TIF_SINGLESTEP); 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; #ifdef CONFIG_SH_DSP case PTRACE_GETDSPREGS: { unsigned long dp; ret = -EIO; dp = ((unsigned long) child) + THREAD_SIZE - sizeof(struct pt_dspregs); if (*((int *) (dp - 4)) == SR_FD) { copy_to_user(addr, (void *) dp, sizeof(struct pt_dspregs)); ret = 0; } break; } case PTRACE_SETDSPREGS: { unsigned long dp; ret = -EIO; dp = ((unsigned long) child) + THREAD_SIZE - sizeof(struct pt_dspregs); if (*((int *) (dp - 4)) == SR_FD) { copy_from_user((void *) dp, addr, sizeof(struct pt_dspregs)); ret = 0; } break; } #endif default: ret = ptrace_request(child, request, addr, data); break; } return ret; } asmlinkage void do_syscall_trace(void) { struct task_struct *tsk = current; if (!test_thread_flag(TIF_SYSCALL_TRACE) && !test_thread_flag(TIF_SINGLESTEP)) return; if (!(tsk->ptrace & PT_PTRACED)) return; /* the 0x80 provides a way for the tracing parent to distinguish between a syscall stop and SIGTRAP delivery */ ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) && !test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0)); /* * 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; } }