diff options
Diffstat (limited to 'arch/sh64/kernel/ptrace.c')
| -rw-r--r-- | arch/sh64/kernel/ptrace.c | 376 |
1 files changed, 376 insertions, 0 deletions
diff --git a/arch/sh64/kernel/ptrace.c b/arch/sh64/kernel/ptrace.c new file mode 100644 index 00000000000..800288c1562 --- /dev/null +++ b/arch/sh64/kernel/ptrace.c @@ -0,0 +1,376 @@ +/* + * 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 <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 ((unsigned long) data > _NSIG) + 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 ((unsigned long) data > _NSIG) + 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.. */ +} |