Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 282 insertions, 0 deletions

diff --git a/arch/v850/kernel/ptrace.c b/arch/v850/kernel/ptrace.c
new file mode 100644
index 00000000000..8fa780757dc
--- /dev/null
+++ b/arch/v850/kernel/ptrace.c
@@ -0,0 +1,282 @@
+/*
+ * arch/v850/kernel/ptrace.c -- `ptrace' system call
+ *
+ *  Copyright (C) 2002,03,04  NEC Electronics Corporation
+ *  Copyright (C) 2002,03,04  Miles Bader <miles@gnu.org>
+ *
+ * Derived from arch/mips/kernel/ptrace.c:
+ *
+ *  Copyright (C) 1992 Ross Biro
+ *  Copyright (C) Linus Torvalds
+ *  Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
+ *  Copyright (C) 1996 David S. Miller
+ *  Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
+ *  Copyright (C) 1999 MIPS Technologies, Inc.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#include <linux/ptrace.h>
+
+#include <asm/errno.h>
+#include <asm/ptrace.h>
+#include <asm/processor.h>
+#include <asm/uaccess.h>
+
+/* Returns the address where the register at REG_OFFS in P is stashed away.  */
+static v850_reg_t *reg_save_addr (unsigned reg_offs, struct task_struct *t)
+{
+	struct pt_regs *regs;
+
+	/* Three basic cases:
+
+	   (1) A register normally saved before calling the scheduler, is
+	       available in the kernel entry pt_regs structure at the top
+	       of the kernel stack.  The kernel trap/irq exit path takes
+	       care to save/restore almost all registers for ptrace'd
+	       processes.
+
+	   (2) A call-clobbered register, where the process P entered the
+	       kernel via [syscall] trap, is not stored anywhere; that's
+	       OK, because such registers are not expected to be preserved
+	       when the trap returns anyway (so we don't actually bother to
+	       test for this case).
+
+	   (3) A few registers not used at all by the kernel, and so
+	       normally never saved except by context-switches, are in the
+	       context switch state.  */
+
+	if (reg_offs == PT_CTPC || reg_offs == PT_CTPSW || reg_offs == PT_CTBP)
+		/* Register saved during context switch.  */
+		regs = thread_saved_regs (t);
+	else
+		/* Register saved during kernel entry (or not available).  */
+		regs = task_regs (t);
+
+	return (v850_reg_t *)((char *)regs + reg_offs);
+}
+
+/* Set the bits SET and clear the bits CLEAR in the v850e DIR
+   (`debug information register').  Returns the new value of DIR.  */
+static inline v850_reg_t set_dir (v850_reg_t set, v850_reg_t clear)
+{
+	register v850_reg_t rval asm ("r10");
+	register v850_reg_t arg0 asm ("r6") = set;
+	register v850_reg_t arg1 asm ("r7") = clear;
+
+	/* The dbtrap handler has exactly this functionality when called
+	   from kernel mode.  0xf840 is a `dbtrap' insn.  */
+	asm (".short 0xf840" : "=r" (rval) : "r" (arg0), "r" (arg1));
+
+	return rval;
+}
+
+/* Makes sure hardware single-stepping is (globally) enabled.
+   Returns true if successful.  */
+static inline int enable_single_stepping (void)
+{
+	static int enabled = 0;	/* Remember whether we already did it.  */
+	if (! enabled) {
+		/* Turn on the SE (`single-step enable') bit, 0x100, in the
+		   DIR (`debug information register').  This may fail if a
+		   processor doesn't support it or something.  We also try
+		   to clear bit 0x40 (`INI'), which is necessary to use the
+		   debug stuff on the v850e2; on the v850e, clearing 0x40
+		   shouldn't cause any problem.  */
+		v850_reg_t dir = set_dir (0x100, 0x40);
+		/* Make sure it really got set.  */
+		if (dir & 0x100)
+			enabled = 1;
+	}
+	return enabled;
+}
+
+/* Try to set CHILD's single-step flag to VAL.  Returns true if successful.  */
+static int set_single_step (struct task_struct *t, int val)
+{
+	v850_reg_t *psw_addr = reg_save_addr(PT_PSW, t);
+	if (val) {
+		/* Make sure single-stepping is enabled.  */
+		if (! enable_single_stepping ())
+			return 0;
+		/* Set T's single-step flag.  */
+		*psw_addr |= 0x800;
+	} else
+		*psw_addr &= ~0x800;
+	return 1;
+}
+
+int sys_ptrace(long request, long pid, long addr, long data)
+{
+	struct task_struct *child;
+	int rval;
+
+	lock_kernel();
+
+	if (request == PTRACE_TRACEME) {
+		/* are we already being traced? */
+		if (current->ptrace & PT_PTRACED) {
+			rval = -EPERM;
+			goto out;
+		}
+		/* set the ptrace bit in the process flags. */
+		current->ptrace |= PT_PTRACED;
+		rval = 0;
+		goto out;
+	}
+	rval = -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;
+
+	rval = -EPERM;
+	if (pid == 1)		/* you may not mess with init */
+		goto out_tsk;
+
+	if (request == PTRACE_ATTACH) {
+		rval = ptrace_attach(child);
+		goto out_tsk;
+	}
+	rval = ptrace_check_attach(child, request == PTRACE_KILL);
+	if (rval < 0)
+		goto out_tsk;
+
+	switch (request) {
+		unsigned long val, copied;
+
+	case PTRACE_PEEKTEXT: /* read word at location addr. */
+	case PTRACE_PEEKDATA:
+		copied = access_process_vm(child, addr, &val, sizeof(val), 0);
+		rval = -EIO;
+		if (copied != sizeof(val))
+			break;
+		rval = put_user(val, (unsigned long *)data);
+		goto out;
+
+	case PTRACE_POKETEXT: /* write the word at location addr. */
+	case PTRACE_POKEDATA:
+		rval = 0;
+		if (access_process_vm(child, addr, &data, sizeof(data), 1)
+		    == sizeof(data))
+			break;
+		rval = -EIO;
+		goto out;
+
+	/* Read/write the word at location ADDR in the registers.  */
+	case PTRACE_PEEKUSR:
+	case PTRACE_POKEUSR:
+		rval = 0;
+		if (addr >= PT_SIZE && request == PTRACE_PEEKUSR) {
+			/* Special requests that don't actually correspond
+			   to offsets in struct pt_regs.  */
+			if (addr == PT_TEXT_ADDR)
+				val = child->mm->start_code;
+			else if (addr == PT_DATA_ADDR)
+				val = child->mm->start_data;
+			else if (addr == PT_TEXT_LEN)
+				val = child->mm->end_code
+					- child->mm->start_code;
+			else
+				rval = -EIO;
+		} else if (addr >= 0 && addr < PT_SIZE && (addr & 0x3) == 0) {
+			v850_reg_t *reg_addr = reg_save_addr(addr, child);
+			if (request == PTRACE_PEEKUSR)
+				val = *reg_addr;
+			else
+				*reg_addr = data;
+		} else
+			rval = -EIO;
+
+		if (rval == 0 && request == PTRACE_PEEKUSR)
+			rval = put_user (val, (unsigned long *)data);
+		goto out;
+
+	/* Continue and stop at next (return from) syscall */
+	case PTRACE_SYSCALL:
+	/* Restart after a signal.  */
+	case PTRACE_CONT:
+	/* Execute a single instruction. */
+	case PTRACE_SINGLESTEP:
+		rval = -EIO;
+		if ((unsigned long) data > _NSIG)
+			break;
+
+		/* Turn CHILD's single-step flag on or off.  */
+		if (! set_single_step (child, request == PTRACE_SINGLESTEP))
+			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);
+		rval = 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:
+		rval = 0;
+		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
+			break;
+		child->exit_code = SIGKILL;
+		wake_up_process(child);
+		break;
+
+	case PTRACE_DETACH: /* detach a process that was attached. */
+		set_single_step (child, 0);  /* Clear single-step flag */
+		rval = ptrace_detach(child, data);
+		break;
+
+	default:
+		rval = -EIO;
+		goto out;
+	}
+
+out_tsk:
+	put_task_struct(child);
+out:
+	unlock_kernel();
+	return rval;
+}
+
+asmlinkage void syscall_trace(void)
+{
+	if (!test_thread_flag(TIF_SYSCALL_TRACE))
+		return;
+	if (!(current->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)
+				 ? 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 ptrace_disable (struct task_struct *child)
+{
+	/* nothing to do */
+}