parisc: convert to generic compat_sys_ptrace

This patch does the compat_sys_ptrace conversion for parisc.
In addition it does convert the parisc ptrace code to use the
architecture-independent ptrace infrastructure instead of own coding.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

3 files changed, 183 insertions, 258 deletions

diff --git a/arch/parisc/include/asm/ptrace.h b/arch/parisc/include/asm/ptrace.h
index 3e94c5d85ff..afa5333187b 100644
--- a/arch/parisc/include/asm/ptrace.h
+++ b/arch/parisc/include/asm/ptrace.h
@@ -47,6 +47,16 @@ struct pt_regs {
 
 #define task_regs(task) ((struct pt_regs *) ((char *)(task) + TASK_REGS))
 
+#define __ARCH_WANT_COMPAT_SYS_PTRACE
+
+struct task_struct;
+#define arch_has_single_step()	1
+void user_disable_single_step(struct task_struct *task);
+void user_enable_single_step(struct task_struct *task);
+
+#define arch_has_block_step()	1
+void user_enable_block_step(struct task_struct *task);
+
 /* XXX should we use iaoq[1] or iaoq[0] ? */
 #define user_mode(regs)			(((regs)->iaoq[0] & 3) ? 1 : 0)
 #define user_space(regs)		(((regs)->iasq[1] != 0) ? 1 : 0)
diff --git a/arch/parisc/kernel/ptrace.c b/arch/parisc/kernel/ptrace.c
index 49c63797078..90904f9dfc5 100644
--- a/arch/parisc/kernel/ptrace.c
+++ b/arch/parisc/kernel/ptrace.c
@@ -4,6 +4,7 @@
  * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc.
  * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx>
  * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
+ * Copyright (C) 2008 Helge Deller <deller@gmx.de>
  */
 
 #include <linux/kernel.h>
@@ -27,15 +28,149 @@
 /* PSW bits we allow the debugger to modify */
 #define USER_PSW_BITS	(PSW_N | PSW_V | PSW_CB)
 
-#undef DEBUG_PTRACE
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure single step bits etc are not set.
+ */
+void ptrace_disable(struct task_struct *task)
+{
+	task->ptrace &= ~(PT_SINGLESTEP|PT_BLOCKSTEP);
 
-#ifdef DEBUG_PTRACE
-#define DBG(x...)	printk(x)
-#else
-#define DBG(x...)
-#endif
+	/* make sure the trap bits are not set */
+	pa_psw(task)->r = 0;
+	pa_psw(task)->t = 0;
+	pa_psw(task)->h = 0;
+	pa_psw(task)->l = 0;
+}
+
+/*
+ * The following functions are called by ptrace_resume() when
+ * enabling or disabling single/block tracing.
+ */
+void user_disable_single_step(struct task_struct *task)
+{
+	ptrace_disable(task);
+}
+
+void user_enable_single_step(struct task_struct *task)
+{
+	task->ptrace &= ~PT_BLOCKSTEP;
+	task->ptrace |= PT_SINGLESTEP;
+
+	if (pa_psw(task)->n) {
+		struct siginfo si;
+
+		/* Nullified, just crank over the queue. */
+		task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
+		task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
+		task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
+		pa_psw(task)->n = 0;
+		pa_psw(task)->x = 0;
+		pa_psw(task)->y = 0;
+		pa_psw(task)->z = 0;
+		pa_psw(task)->b = 0;
+		ptrace_disable(task);
+		/* Don't wake up the task, but let the
+		   parent know something happened. */
+		si.si_code = TRAP_TRACE;
+		si.si_addr = (void __user *) (task_regs(task)->iaoq[0] & ~3);
+		si.si_signo = SIGTRAP;
+		si.si_errno = 0;
+		force_sig_info(SIGTRAP, &si, task);
+		/* notify_parent(task, SIGCHLD); */
+		return;
+	}
+
+	/* Enable recovery counter traps.  The recovery counter
+	 * itself will be set to zero on a task switch.  If the
+	 * task is suspended on a syscall then the syscall return
+	 * path will overwrite the recovery counter with a suitable
+	 * value such that it traps once back in user space.  We
+	 * disable interrupts in the tasks PSW here also, to avoid
+	 * interrupts while the recovery counter is decrementing.
+	 */
+	pa_psw(task)->r = 1;
+	pa_psw(task)->t = 0;
+	pa_psw(task)->h = 0;
+	pa_psw(task)->l = 0;
+}
+
+void user_enable_block_step(struct task_struct *task)
+{
+	task->ptrace &= ~PT_SINGLESTEP;
+	task->ptrace |= PT_BLOCKSTEP;
+
+	/* Enable taken branch trap. */
+	pa_psw(task)->r = 0;
+	pa_psw(task)->t = 1;
+	pa_psw(task)->h = 0;
+	pa_psw(task)->l = 0;
+}
+
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
+{
+	unsigned long tmp;
+	long ret = -EIO;
 
-#ifdef CONFIG_64BIT
+	switch (request) {
+
+	/* Read the word at location addr in the USER area.  For ptraced
+	   processes, the kernel saves all regs on a syscall. */
+	case PTRACE_PEEKUSR:
+		if ((addr & (sizeof(long)-1)) ||
+		    (unsigned long) addr >= sizeof(struct pt_regs))
+			break;
+		tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
+		ret = put_user(tmp, (unsigned long *) data);
+		break;
+
+	/* Write the word at location addr in the USER area.  This will need
+	   to change when the kernel no longer saves all regs on a syscall.
+	   FIXME.  There is a problem at the moment in that r3-r18 are only
+	   saved if the process is ptraced on syscall entry, and even then
+	   those values are overwritten by actual register values on syscall
+	   exit. */
+	case PTRACE_POKEUSR:
+		/* Some register values written here may be ignored in
+		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
+		 * r31/r31+4, and not with the values in pt_regs.
+		 */
+		if (addr == PT_PSW) {
+			/* Allow writing to Nullify, Divide-step-correction,
+			 * and carry/borrow bits.
+			 * BEWARE, if you set N, and then single step, it won't
+			 * stop on the nullified instruction.
+			 */
+			data &= USER_PSW_BITS;
+			task_regs(child)->gr[0] &= ~USER_PSW_BITS;
+			task_regs(child)->gr[0] |= data;
+			ret = 0;
+			break;
+		}
+
+		if ((addr & (sizeof(long)-1)) ||
+		    (unsigned long) addr >= sizeof(struct pt_regs))
+			break;
+		if ((addr >= PT_GR1 && addr <= PT_GR31) ||
+				addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
+				(addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
+				addr == PT_SAR) {
+			*(unsigned long *) ((char *) task_regs(child) + addr) = data;
+			ret = 0;
+		}
+		break;
+
+	default:
+		ret = ptrace_request(child, request, addr, data);
+		break;
+	}
+
+	return ret;
+}
+
+
+#ifdef CONFIG_COMPAT
 
 /* This function is needed to translate 32 bit pt_regs offsets in to
  * 64 bit pt_regs offsets.  For example, a 32 bit gdb under a 64 bit kernel
@@ -61,106 +196,25 @@ static long translate_usr_offset(long offset)
 	else
 		return -1;
 }
-#endif
 
-/*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure single step bits etc are not set.
- */
-void ptrace_disable(struct task_struct *child)
+long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
+			compat_ulong_t addr, compat_ulong_t data)
 {
-	/* make sure the trap bits are not set */
-	pa_psw(child)->r = 0;
-	pa_psw(child)->t = 0;
-	pa_psw(child)->h = 0;
-	pa_psw(child)->l = 0;
-}
-
-long arch_ptrace(struct task_struct *child, long request, long addr, long data)
-{
-	long ret;
-#ifdef DEBUG_PTRACE
-	long oaddr=addr, odata=data;
-#endif
+	compat_uint_t tmp;
+	long ret = -EIO;
 
 	switch (request) {
-	case PTRACE_PEEKTEXT: /* read word at location addr. */ 
-	case PTRACE_PEEKDATA: {
-#ifdef CONFIG_64BIT
-		if (__is_compat_task(child)) {
-			int copied;
-			unsigned int tmp;
-
-			addr &= 0xffffffffL;
-			copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
-			ret = -EIO;
-			if (copied != sizeof(tmp))
-				goto out_tsk;
-			ret = put_user(tmp,(unsigned int *) data);
-			DBG("sys_ptrace(PEEK%s, %d, %lx, %lx) returning %ld, data %x\n",
-				request == PTRACE_PEEKTEXT ? "TEXT" : "DATA",
-				pid, oaddr, odata, ret, tmp);
-		}
-		else
-#endif
-			ret = generic_ptrace_peekdata(child, addr, data);
-		goto out_tsk;
-	}
 
-	/* 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;
-#ifdef CONFIG_64BIT
-		if (__is_compat_task(child)) {
-			unsigned int tmp = (unsigned int)data;
-			DBG("sys_ptrace(POKE%s, %d, %lx, %lx)\n",
-				request == PTRACE_POKETEXT ? "TEXT" : "DATA",
-				pid, oaddr, odata);
-			addr &= 0xffffffffL;
-			if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1) == sizeof(tmp))
-				goto out_tsk;
-		}
-		else
-#endif
-		{
-			if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
-				goto out_tsk;
-		}
-		ret = -EIO;
-		goto out_tsk;
-
-	/* Read the word at location addr in the USER area.  For ptraced
-	   processes, the kernel saves all regs on a syscall. */
-	case PTRACE_PEEKUSR: {
-		ret = -EIO;
-#ifdef CONFIG_64BIT
-		if (__is_compat_task(child)) {
-			unsigned int tmp;
-
-			if (addr & (sizeof(int)-1))
-				goto out_tsk;
-			if ((addr = translate_usr_offset(addr)) < 0)
-				goto out_tsk;
-
-			tmp = *(unsigned int *) ((char *) task_regs(child) + addr);
-			ret = put_user(tmp, (unsigned int *) data);
-			DBG("sys_ptrace(PEEKUSR, %d, %lx, %lx) returning %ld, addr %lx, data %x\n",
-				pid, oaddr, odata, ret, addr, tmp);
-		}
-		else
-#endif
-		{
-			unsigned long tmp;
+	case PTRACE_PEEKUSR:
+		if (addr & (sizeof(compat_uint_t)-1))
+			break;
+		addr = translate_usr_offset(addr);
+		if (addr < 0)
+			break;
 
-			if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs))
-				goto out_tsk;
-			tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
-			ret = put_user(tmp, (unsigned long *) data);
-		}
-		goto out_tsk;
-	}
+		tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
+		ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
+		break;
 
 	/* Write the word at location addr in the USER area.  This will need
 	   to change when the kernel no longer saves all regs on a syscall.
@@ -169,185 +223,46 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 	   those values are overwritten by actual register values on syscall
 	   exit. */
 	case PTRACE_POKEUSR:
-		ret = -EIO;
 		/* Some register values written here may be ignored in
 		 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
 		 * r31/r31+4, and not with the values in pt_regs.
 		 */
-		 /* PT_PSW=0, so this is valid for 32 bit processes under 64
-		 * bit kernels.
-		 */
 		if (addr == PT_PSW) {
-			/* PT_PSW=0, so this is valid for 32 bit processes
-			 * under 64 bit kernels.
-			 *
-			 * Allow writing to Nullify, Divide-step-correction,
-			 * and carry/borrow bits.
-			 * BEWARE, if you set N, and then single step, it won't
-			 * stop on the nullified instruction.
+			/* Since PT_PSW==0, it is valid for 32 bit processes
+			 * under 64 bit kernels as well.
 			 */
-			DBG("sys_ptrace(POKEUSR, %d, %lx, %lx)\n",
-				pid, oaddr, odata);
-			data &= USER_PSW_BITS;
-			task_regs(child)->gr[0] &= ~USER_PSW_BITS;
-			task_regs(child)->gr[0] |= data;
-			ret = 0;
-			goto out_tsk;
-		}
-#ifdef CONFIG_64BIT
-		if (__is_compat_task(child)) {
-			if (addr & (sizeof(int)-1))
-				goto out_tsk;
-			if ((addr = translate_usr_offset(addr)) < 0)
-				goto out_tsk;
-			DBG("sys_ptrace(POKEUSR, %d, %lx, %lx) addr %lx\n",
-				pid, oaddr, odata, addr);
+			ret = arch_ptrace(child, request, addr, data);
+		} else {
+			if (addr & (sizeof(compat_uint_t)-1))
+				break;
+			addr = translate_usr_offset(addr);
+			if (addr < 0)
+				break;
 			if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
 				/* Special case, fp regs are 64 bits anyway */
-				*(unsigned int *) ((char *) task_regs(child) + addr) = data;
+				*(__u64 *) ((char *) task_regs(child) + addr) = data;
 				ret = 0;
 			}
 			else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
 					addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
 					addr == PT_SAR+4) {
 				/* Zero the top 32 bits */
-				*(unsigned int *) ((char *) task_regs(child) + addr - 4) = 0;
-				*(unsigned int *) ((char *) task_regs(child) + addr) = data;
+				*(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
+				*(__u32 *) ((char *) task_regs(child) + addr) = data;
 				ret = 0;
 			}
-			goto out_tsk;
 		}
-		else
-#endif
-		{
-			if ((addr & (sizeof(long)-1)) || (unsigned long) addr >= sizeof(struct pt_regs))
-				goto out_tsk;
-			if ((addr >= PT_GR1 && addr <= PT_GR31) ||
-					addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
-					(addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
-					addr == PT_SAR) {
-				*(unsigned long *) ((char *) task_regs(child) + addr) = data;
-				ret = 0;
-			}
-			goto out_tsk;
-		}
-
-	case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
-	case PTRACE_CONT:
-		ret = -EIO;
-		DBG("sys_ptrace(%s)\n",
-			request == PTRACE_SYSCALL ? "SYSCALL" : "CONT");
-		if (!valid_signal(data))
-			goto out_tsk;
-		child->ptrace &= ~(PT_SINGLESTEP|PT_BLOCKSTEP);
-		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;
-		goto out_wake_notrap;
-
-	case PTRACE_KILL:
-		/*
-		 * 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.
-		 */
-		ret = 0;
-		DBG("sys_ptrace(KILL)\n");
-		if (child->exit_state == EXIT_ZOMBIE)	/* already dead */
-			goto out_tsk;
-		child->exit_code = SIGKILL;
-		goto out_wake_notrap;
-
-	case PTRACE_SINGLEBLOCK:
-		DBG("sys_ptrace(SINGLEBLOCK)\n");
-		ret = -EIO;
-		if (!valid_signal(data))
-			goto out_tsk;
-		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-		child->ptrace &= ~PT_SINGLESTEP;
-		child->ptrace |= PT_BLOCKSTEP;
-		child->exit_code = data;
-
-		/* Enable taken branch trap. */
-		pa_psw(child)->r = 0;
-		pa_psw(child)->t = 1;
-		pa_psw(child)->h = 0;
-		pa_psw(child)->l = 0;
-		goto out_wake;
-
-	case PTRACE_SINGLESTEP:
-		DBG("sys_ptrace(SINGLESTEP)\n");
-		ret = -EIO;
-		if (!valid_signal(data))
-			goto out_tsk;
-
-		clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-		child->ptrace &= ~PT_BLOCKSTEP;
-		child->ptrace |= PT_SINGLESTEP;
-		child->exit_code = data;
-
-		if (pa_psw(child)->n) {
-			struct siginfo si;
-
-			/* Nullified, just crank over the queue. */
-			task_regs(child)->iaoq[0] = task_regs(child)->iaoq[1];
-			task_regs(child)->iasq[0] = task_regs(child)->iasq[1];
-			task_regs(child)->iaoq[1] = task_regs(child)->iaoq[0] + 4;
-			pa_psw(child)->n = 0;
-			pa_psw(child)->x = 0;
-			pa_psw(child)->y = 0;
-			pa_psw(child)->z = 0;
-			pa_psw(child)->b = 0;
-			ptrace_disable(child);
-			/* Don't wake up the child, but let the
-			   parent know something happened. */
-			si.si_code = TRAP_TRACE;
-			si.si_addr = (void __user *) (task_regs(child)->iaoq[0] & ~3);
-			si.si_signo = SIGTRAP;
-			si.si_errno = 0;
-			force_sig_info(SIGTRAP, &si, child);
-			//notify_parent(child, SIGCHLD);
-			//ret = 0;
-			goto out_wake;
-		}
-
-		/* Enable recovery counter traps.  The recovery counter
-		 * itself will be set to zero on a task switch.  If the
-		 * task is suspended on a syscall then the syscall return
-		 * path will overwrite the recovery counter with a suitable
-		 * value such that it traps once back in user space.  We
-		 * disable interrupts in the childs PSW here also, to avoid
-		 * interrupts while the recovery counter is decrementing.
-		 */
-		pa_psw(child)->r = 1;
-		pa_psw(child)->t = 0;
-		pa_psw(child)->h = 0;
-		pa_psw(child)->l = 0;
-		/* give it a chance to run. */
-		goto out_wake;
-
-	case PTRACE_GETEVENTMSG:
-                ret = put_user(child->ptrace_message, (unsigned int __user *) data);
-		goto out_tsk;
+		break;
 
 	default:
-		ret = ptrace_request(child, request, addr, data);
-		goto out_tsk;
+		ret = compat_ptrace_request(child, request, addr, data);
+		break;
 	}
 
-out_wake_notrap:
-	ptrace_disable(child);
-out_wake:
-	wake_up_process(child);
-	ret = 0;
-out_tsk:
-	DBG("arch_ptrace(%ld, %d, %lx, %lx) returning %ld\n",
-		request, pid, oaddr, odata, ret);
 	return ret;
 }
+#endif
+
 
 void syscall_trace(void)
 {
diff --git a/arch/parisc/kernel/syscall_table.S b/arch/parisc/kernel/syscall_table.S
index 6084667eacf..4ed01f2d655 100644
--- a/arch/parisc/kernel/syscall_table.S
+++ b/arch/parisc/kernel/syscall_table.S
@@ -87,7 +87,7 @@
 	ENTRY_SAME(setuid)
 	ENTRY_SAME(getuid)
 	ENTRY_COMP(stime)		/* 25 */
-	ENTRY_SAME(ptrace)
+	ENTRY_COMP(ptrace)
 	ENTRY_SAME(alarm)
 	/* see stat comment */
 	ENTRY_COMP(newfstat)