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-rw-r--r--arch/sh64/kernel/ptrace.c376
1 files changed, 376 insertions, 0 deletions
diff --git a/arch/sh64/kernel/ptrace.c b/arch/sh64/kernel/ptrace.c
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+++ b/arch/sh64/kernel/ptrace.c
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+/*
+ * 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.. */
+}