| /* |
| * 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 |
| * Copyright (C) 2003 Paul Mundt |
| * |
| * 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 <linux/config.h> |
| #include <linux/kernel.h> |
| #include <linux/rwsem.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 <linux/signal.h> |
| |
| #include <asm/io.h> |
| #include <asm/uaccess.h> |
| #include <asm/pgtable.h> |
| #include <asm/system.h> |
| #include <asm/processor.h> |
| #include <asm/mmu_context.h> |
| |
| /* 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 from the user area in the process kernel stack. |
| */ |
| static inline int get_stack_long(struct task_struct *task, int offset) |
| { |
| unsigned char *stack; |
| |
| stack = (unsigned char *)(task->thread.uregs); |
| 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 (!tsk_used_math(task)) { |
| 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 into the user area in 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.uregs); |
| 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 (!tsk_used_math(task)) { |
| fpinit(&task->thread.fpu.hard); |
| set_stopped_child_used_math(task); |
| } 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; |
| extern void poke_real_address_q(unsigned long long addr, unsigned long long data); |
| #define WPC_DBRMODE 0x0d104008 |
| static int first_call = 1; |
| int ret; |
| |
| lock_kernel(); |
| |
| if (first_call) { |
| /* Set WPC.DBRMODE to 0. This makes all debug events get |
| * delivered through RESVEC, i.e. into the handlers in entry.S. |
| * (If the kernel was downloaded using a remote gdb, WPC.DBRMODE |
| * would normally be left set to 1, which makes debug events get |
| * delivered through DBRVEC, i.e. into the remote gdb's |
| * handlers. This prevents ptrace getting them, and confuses |
| * the remote gdb.) */ |
| printk("DBRMODE set to 0 to permit native debugging\n"); |
| poke_real_address_q(WPC_DBRMODE, 0); |
| first_call = 0; |
| } |
| |
| 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 = ptrace_check_attach(child, request == PTRACE_KILL); |
| if (ret < 0) |
| 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 = !!tsk_used_math(child); |
| } 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 (!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); |
| 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; |
| child->exit_code = SIGKILL; |
| wake_up_process(child); |
| break; |
| } |
| |
| case PTRACE_SINGLESTEP: { /* set the trap flag. */ |
| struct pt_regs *regs; |
| |
| 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; |
| } |
| |
| regs = child->thread.uregs; |
| |
| 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; |
| |
| default: |
| ret = ptrace_request(child, request, addr, data); |
| break; |
| } |
| out_tsk: |
| put_task_struct(child); |
| out: |
| unlock_kernel(); |
| return ret; |
| } |
| |
| asmlinkage void syscall_trace(void) |
| { |
| struct task_struct *tsk = current; |
| |
| if (!test_thread_flag(TIF_SYSCALL_TRACE)) |
| return; |
| if (!(tsk->ptrace & PT_PTRACED)) |
| return; |
| |
| ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) |
| ? 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; |
| } |
| } |
| |
| /* 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. */ |
| local_irq_enable(); |
| 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. */ |
| local_irq_enable(); |
| 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.. */ |
| } |