powerpc: merge ptrace.c

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

1 files changed, 613 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
new file mode 100644
index 000000000000..336b8bf542d7
--- /dev/null
+++ b/arch/powerpc/kernel/ptrace.c
@@ -0,0 +1,613 @@
+/*
+ *  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/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 <linux/security.h>
+#include <linux/signal.h>
+#include <linux/seccomp.h>
+#include <linux/audit.h>
+#ifdef CONFIG_PPC32
+#include <linux/module.h>
+#endif
+
+#include <asm/uaccess.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#ifdef CONFIG_PPC64
+#include <asm/ptrace-common.h>
+#endif
+
+#ifdef CONFIG_PPC32
+/*
+ * Set of msr bits that gdb can change on behalf of a process.
+ */
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+#define MSR_DEBUGCHANGE	0
+#else
+#define MSR_DEBUGCHANGE	(MSR_SE | MSR_BE)
+#endif
+#endif /* CONFIG_PPC32 */
+
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+#ifdef CONFIG_PPC32
+/*
+ * Get contents of register REGNO in task TASK.
+ */
+static inline unsigned long get_reg(struct task_struct *task, int regno)
+{
+	if (regno < sizeof(struct pt_regs) / sizeof(unsigned long)
+	    && task->thread.regs != NULL)
+		return ((unsigned long *)task->thread.regs)[regno];
+	return (0);
+}
+
+/*
+ * Write contents of register REGNO in task TASK.
+ */
+static inline int put_reg(struct task_struct *task, int regno,
+			  unsigned long data)
+{
+	if (regno <= PT_MQ && task->thread.regs != NULL) {
+		if (regno == PT_MSR)
+			data = (data & MSR_DEBUGCHANGE)
+				| (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
+		((unsigned long *)task->thread.regs)[regno] = data;
+		return 0;
+	}
+	return -EIO;
+}
+
+#ifdef CONFIG_ALTIVEC
+/*
+ * Get contents of AltiVec register state in task TASK
+ */
+static inline int get_vrregs(unsigned long __user *data, struct task_struct *task)
+{
+	int i, j;
+
+	if (!access_ok(VERIFY_WRITE, data, 133 * sizeof(unsigned long)))
+		return -EFAULT;
+
+	/* copy AltiVec registers VR[0] .. VR[31] */
+	for (i = 0; i < 32; i++)
+		for (j = 0; j < 4; j++, data++)
+			if (__put_user(task->thread.vr[i].u[j], data))
+				return -EFAULT;
+
+	/* copy VSCR */
+	for (i = 0; i < 4; i++, data++)
+		if (__put_user(task->thread.vscr.u[i], data))
+			return -EFAULT;
+
+        /* copy VRSAVE */
+	if (__put_user(task->thread.vrsave, data))
+		return -EFAULT;
+
+	return 0;
+}
+
+/*
+ * Write contents of AltiVec register state into task TASK.
+ */
+static inline int set_vrregs(struct task_struct *task, unsigned long __user *data)
+{
+	int i, j;
+
+	if (!access_ok(VERIFY_READ, data, 133 * sizeof(unsigned long)))
+		return -EFAULT;
+
+	/* copy AltiVec registers VR[0] .. VR[31] */
+	for (i = 0; i < 32; i++)
+		for (j = 0; j < 4; j++, data++)
+			if (__get_user(task->thread.vr[i].u[j], data))
+				return -EFAULT;
+
+	/* copy VSCR */
+	for (i = 0; i < 4; i++, data++)
+		if (__get_user(task->thread.vscr.u[i], data))
+			return -EFAULT;
+
+	/* copy VRSAVE */
+	if (__get_user(task->thread.vrsave, data))
+		return -EFAULT;
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_SPE
+
+/*
+ * For get_evrregs/set_evrregs functions 'data' has the following layout:
+ *
+ * struct {
+ *   u32 evr[32];
+ *   u64 acc;
+ *   u32 spefscr;
+ * }
+ */
+
+/*
+ * Get contents of SPE register state in task TASK.
+ */
+static inline int get_evrregs(unsigned long *data, struct task_struct *task)
+{
+	int i;
+
+	if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long)))
+		return -EFAULT;
+
+	/* copy SPEFSCR */
+	if (__put_user(task->thread.spefscr, &data[34]))
+		return -EFAULT;
+
+	/* copy SPE registers EVR[0] .. EVR[31] */
+	for (i = 0; i < 32; i++, data++)
+		if (__put_user(task->thread.evr[i], data))
+			return -EFAULT;
+
+	/* copy ACC */
+	if (__put_user64(task->thread.acc, (unsigned long long *)data))
+		return -EFAULT;
+
+	return 0;
+}
+
+/*
+ * Write contents of SPE register state into task TASK.
+ */
+static inline int set_evrregs(struct task_struct *task, unsigned long *data)
+{
+	int i;
+
+	if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long)))
+		return -EFAULT;
+
+	/* copy SPEFSCR */
+	if (__get_user(task->thread.spefscr, &data[34]))
+		return -EFAULT;
+
+	/* copy SPE registers EVR[0] .. EVR[31] */
+	for (i = 0; i < 32; i++, data++)
+		if (__get_user(task->thread.evr[i], data))
+			return -EFAULT;
+	/* copy ACC */
+	if (__get_user64(task->thread.acc, (unsigned long long*)data))
+		return -EFAULT;
+
+	return 0;
+}
+#endif /* CONFIG_SPE */
+
+static inline void
+set_single_step(struct task_struct *task)
+{
+	struct pt_regs *regs = task->thread.regs;
+
+	if (regs != NULL) {
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+		task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC;
+		regs->msr |= MSR_DE;
+#else
+		regs->msr |= MSR_SE;
+#endif
+	}
+}
+
+static inline void
+clear_single_step(struct task_struct *task)
+{
+	struct pt_regs *regs = task->thread.regs;
+
+	if (regs != NULL) {
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+		task->thread.dbcr0 = 0;
+		regs->msr &= ~MSR_DE;
+#else
+		regs->msr &= ~MSR_SE;
+#endif
+	}
+}
+#endif /* CONFIG_PPC32 */
+
+/*
+ * 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, tmp;
+
+		ret = -EIO;
+		/* convert to index and check */
+#ifdef CONFIG_PPC32
+		index = (unsigned long) addr >> 2;
+		if ((addr & 3) || (index > PT_FPSCR)
+		    || (child->thread.regs == NULL))
+#else
+		index = (unsigned long) addr >> 3;
+		if ((addr & 7) || (index > PT_FPSCR))
+#endif
+			break;
+
+#ifdef CONFIG_PPC32
+		CHECK_FULL_REGS(child->thread.regs);
+#endif
+		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 */
+#ifdef CONFIG_PPC32
+		index = (unsigned long) addr >> 2;
+		if ((addr & 3) || (index > PT_FPSCR)
+		    || (child->thread.regs == NULL))
+#else
+		index = (unsigned long) addr >> 3;
+		if ((addr & 7) || (index > PT_FPSCR))
+#endif
+			break;
+
+#ifdef CONFIG_PPC32
+		CHECK_FULL_REGS(child->thread.regs);
+#endif
+		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 (!valid_signal(data))
+			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 (!valid_signal(data))
+			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;
+	}
+
+#ifdef CONFIG_PPC64
+	case PTRACE_GET_DEBUGREG: {
+		ret = -EINVAL;
+		/* We only support one DABR and no IABRS at the moment */
+		if (addr > 0)
+			break;
+		ret = put_user(child->thread.dabr,
+			       (unsigned long __user *)data);
+		break;
+	}
+
+	case PTRACE_SET_DEBUGREG:
+		ret = ptrace_set_debugreg(child, addr, data);
+		break;
+#endif
+
+	case PTRACE_DETACH:
+		ret = ptrace_detach(child, data);
+		break;
+
+#ifdef CONFIG_PPC64
+	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;
+	}
+#endif /* CONFIG_PPC64 */
+
+#ifdef CONFIG_ALTIVEC
+	case PTRACE_GETVRREGS:
+		/* Get the child altivec register state. */
+		flush_altivec_to_thread(child);
+		ret = get_vrregs((unsigned long __user *)data, child);
+		break;
+
+	case PTRACE_SETVRREGS:
+		/* Set the child altivec register state. */
+		flush_altivec_to_thread(child);
+		ret = set_vrregs(child, (unsigned long __user *)data);
+		break;
+#endif
+#ifdef CONFIG_SPE
+	case PTRACE_GETEVRREGS:
+		/* Get the child spe register state. */
+		if (child->thread.regs->msr & MSR_SPE)
+			giveup_spe(child);
+		ret = get_evrregs((unsigned long __user *)data, child);
+		break;
+
+	case PTRACE_SETEVRREGS:
+		/* Set the child spe register state. */
+		/* this is to clear the MSR_SPE bit to force a reload
+		 * of register state from memory */
+		if (child->thread.regs->msr & MSR_SPE)
+			giveup_spe(child);
+		ret = set_evrregs(child, (unsigned long __user *)data);
+		break;
+#endif
+
+	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)
+{
+#ifdef CONFIG_PPC64
+	secure_computing(regs->gpr[0]);
+#endif
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE)
+	    && (current->ptrace & PT_PTRACED))
+		do_syscall_trace();
+
+	if (unlikely(current->audit_context))
+		audit_syscall_entry(current,
+#ifdef CONFIG_PPC32
+				    AUDIT_ARCH_PPC,
+#else
+				    test_thread_flag(TIF_32BIT)?AUDIT_ARCH_PPC:AUDIT_ARCH_PPC64,
+#endif
+				    regs->gpr[0],
+				    regs->gpr[3], regs->gpr[4],
+				    regs->gpr[5], regs->gpr[6]);
+}
+
+void do_syscall_trace_leave(struct pt_regs *regs)
+{
+#ifdef CONFIG_PPC32
+	secure_computing(regs->gpr[0]);
+#endif
+
+	if (unlikely(current->audit_context))
+		audit_syscall_exit(current,
+				   (regs->ccr&0x1000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
+				   regs->result);
+
+	if ((test_thread_flag(TIF_SYSCALL_TRACE)
+#ifdef CONFIG_PPC64
+	     || test_thread_flag(TIF_SINGLESTEP)
+#endif
+	     )
+	    && (current->ptrace & PT_PTRACED))
+		do_syscall_trace();
+}
+
+#ifdef CONFIG_PPC32
+EXPORT_SYMBOL(do_syscall_trace_enter);
+EXPORT_SYMBOL(do_syscall_trace_leave);
+#endif