patch-2.4.22 linux-2.4.22/arch/sh64/kernel/ptrace.c

• Lines: 375
• Date: 2003-08-25 04:44:40.000000000 -0700
• Orig file: linux-2.4.21/arch/sh64/kernel/ptrace.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.21/arch/sh64/kernel/ptrace.c linux-2.4.22/arch/sh64/kernel/ptrace.c
@@ -0,0 +1,374 @@
+/*
+ * 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
+ *
+ * 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/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 off of the process kernel stack.
+ */
+static inline int get_stack_long(struct task_struct *task, int offset)
+{
+	unsigned char *stack;
+
+	stack = (unsigned char *)(task->thread.kregs);
+	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 (!task->used_math) {
+		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 on 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.kregs);
+	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 (!task->used_math) {
+		fpinit(&task->thread.fpu.hard);
+		task->used_math = 1;
+	} 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, *tsk = current;
+	int ret;
+
+	lock_kernel();
+	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 = -ESRCH;
+	if (!(child->ptrace & PT_PTRACED))
+		goto out_tsk;
+	if (child->state != TASK_STOPPED) {
+		if (request != PTRACE_KILL)
+			goto out_tsk;
+	}
+	if (child->p_pptr != tsk)
+		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 = child->used_math;
+		} 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)
+			child->ptrace |= PT_TRACESYS;
+		else
+			child->ptrace &= ~PT_TRACESYS;
+		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->state == TASK_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;
+		child->ptrace &= ~PT_TRACESYS;
+		if ((child->ptrace & PT_DTRACE) == 0) {
+			/* Spurious delayed TF traps may occur */
+			child->ptrace |= PT_DTRACE;
+		}
+
+		regs = child->thread.kregs;
+
+		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;
+
+	case PTRACE_SETOPTIONS: {
+		if (data & PTRACE_O_TRACESYSGOOD)
+			child->ptrace |= PT_TRACESYSGOOD;
+		else
+			child->ptrace &= ~PT_TRACESYSGOOD;
+
+
+
+		ret = 0;
+		break;
+	}
+	default:
+		ret = -EIO;
+		break;
+	}
+out_tsk:
+	free_task_struct(child);
+out:
+	unlock_kernel();
+	return ret;
+}
+
+asmlinkage void syscall_trace(void)
+{
+	struct task_struct *tsk = current;
+
+	if ((tsk->ptrace & (PT_PTRACED|PT_TRACESYS))
+	    != (PT_PTRACED|PT_TRACESYS))
+		return;
+	tsk->exit_code = SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
+				    ? 0x80 : 0);
+	tsk->state = TASK_STOPPED;
+	notify_parent(tsk, SIGCHLD);
+	schedule();
+	/*
+	 * 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. */
+	__sti();
+	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. */
+	__sti();
+	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.. */
+}