1 files changed, 328 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/ptrace.c b/arch/ppc64/kernel/ptrace.c
new file mode 100644
index 000000000000..354a287c67eb
--- /dev/null
+++ b/arch/ppc64/kernel/ptrace.c
@@ -0,0 +1,328 @@
+/*
+ *  linux/arch/ppc64/kernel/ptrace.c
+ *
+ *  PowerPC version
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ *  Derived from "arch/m68k/kernel/ptrace.c"
+ *  Copyright (C) 1994 by Hamish Macdonald
+ *  Taken from linux/kernel/ptrace.c and modified for M680x0.
+ *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
+ *
+ * Modified by Cort Dougan (cort@hq.fsmlabs.com)
+ * and Paul Mackerras (paulus@linuxcare.com.au).
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file README.legal in the main directory of
+ * this archive for more details.
+ */
+
+#include <linux/kernel.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/security.h>
+#include <linux/audit.h>
+#include <linux/seccomp.h>
+
+#include <asm/uaccess.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/ptrace-common.h>
+
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure single step bits etc are not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+	/* make sure the single step bit is not set. */
+	clear_single_step(child);
+}
+
+int sys_ptrace(long request, long pid, long addr, long data)
+{
+	struct task_struct *child;
+	int ret = -EPERM;
+
+	lock_kernel();
+	if (request == PTRACE_TRACEME) {
+		/* are we already being traced? */
+		if (current->ptrace & PT_PTRACED)
+			goto out;
+		ret = security_ptrace(current->parent, current);
+		if (ret)
+			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 __user *) data);
+		break;
+	}
+
+	/* read the word at location addr in the USER area. */
+	case PTRACE_PEEKUSR: {
+		unsigned long index;
+		unsigned long tmp;
+
+		ret = -EIO;
+		/* convert to index and check */
+		index = (unsigned long) addr >> 3;
+		if ((addr & 7) || (index > PT_FPSCR))
+			break;
+
+		if (index < PT_FPR0) {
+			tmp = get_reg(child, (int)index);
+		} else {
+			flush_fp_to_thread(child);
+			tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
+		}
+		ret = put_user(tmp,(unsigned long __user *) data);
+		break;
+	}
+
+	/* If 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;
+
+	/* write the word at location addr in the USER area */
+	case PTRACE_POKEUSR: {
+		unsigned long index;
+
+		ret = -EIO;
+		/* convert to index and check */
+		index = (unsigned long) addr >> 3;
+		if ((addr & 7) || (index > PT_FPSCR))
+			break;
+
+		if (index == PT_ORIG_R3)
+			break;
+		if (index < PT_FPR0) {
+			ret = put_reg(child, index, data);
+		} else {
+			flush_fp_to_thread(child);
+			((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
+			ret = 0;
+		}
+		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;
+		/* make sure the single step bit is not set. */
+		clear_single_step(child);
+		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;
+		/* make sure the single step bit is not set. */
+		clear_single_step(child);
+		wake_up_process(child);
+		break;
+	}
+
+	case PTRACE_SINGLESTEP: {  /* set the trap flag. */
+		ret = -EIO;
+		if ((unsigned long) data > _NSIG)
+			break;
+		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+		set_single_step(child);
+		child->exit_code = data;
+		/* give it a chance to run. */
+		wake_up_process(child);
+		ret = 0;
+		break;
+	}
+
+	case PTRACE_DETACH:
+		ret = ptrace_detach(child, data);
+		break;
+
+	case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
+		int i;
+		unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
+		unsigned long __user *tmp = (unsigned long __user *)addr;
+
+		for (i = 0; i < 32; i++) {
+			ret = put_user(*reg, tmp);
+			if (ret)
+				break;
+			reg++;
+			tmp++;
+		}
+		break;
+	}
+
+	case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
+		int i;
+		unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
+		unsigned long __user *tmp = (unsigned long __user *)addr;
+
+		for (i = 0; i < 32; i++) {
+			ret = get_user(*reg, tmp);
+			if (ret)
+				break;
+			reg++;
+			tmp++;
+		}
+		break;
+	}
+
+	case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
+		int i;
+		unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
+		unsigned long __user *tmp = (unsigned long __user *)addr;
+
+		flush_fp_to_thread(child);
+
+		for (i = 0; i < 32; i++) {
+			ret = put_user(*reg, tmp);
+			if (ret)
+				break;
+			reg++;
+			tmp++;
+		}
+		break;
+	}
+
+	case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
+		int i;
+		unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
+		unsigned long __user *tmp = (unsigned long __user *)addr;
+
+		flush_fp_to_thread(child);
+
+		for (i = 0; i < 32; i++) {
+			ret = get_user(*reg, tmp);
+			if (ret)
+				break;
+			reg++;
+			tmp++;
+		}
+		break;
+	}
+
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+out_tsk:
+	put_task_struct(child);
+out:
+	unlock_kernel();
+	return ret;
+}
+
+static void do_syscall_trace(void)
+{
+	/* 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)
+				 ? 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 (current->exit_code) {
+		send_sig(current->exit_code, current, 1);
+		current->exit_code = 0;
+	}
+}
+
+void do_syscall_trace_enter(struct pt_regs *regs)
+{
+	if (unlikely(current->audit_context))
+		audit_syscall_entry(current, regs->gpr[0],
+				    regs->gpr[3], regs->gpr[4],
+				    regs->gpr[5], regs->gpr[6]);
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE)
+	    && (current->ptrace & PT_PTRACED))
+		do_syscall_trace();
+}
+
+void do_syscall_trace_leave(struct pt_regs *regs)
+{
+	secure_computing(regs->gpr[0]);
+
+	if (unlikely(current->audit_context))
+		audit_syscall_exit(current, regs->result);
+
+	if ((test_thread_flag(TIF_SYSCALL_TRACE)
+	     || test_thread_flag(TIF_SINGLESTEP))
+	    && (current->ptrace & PT_PTRACED))
+		do_syscall_trace();
+}