patch-2.1.23 linux/arch/i386/kernel/ptrace.c

• Lines: 269
• Date: Sun Jan 26 12:07:04 1997
• Orig file: v2.1.22/linux/arch/i386/kernel/ptrace.c
• Orig date: Thu Jan 2 15:55:15 1997

diff -u --recursive --new-file v2.1.22/linux/arch/i386/kernel/ptrace.c linux/arch/i386/kernel/ptrace.c
@@ -6,6 +6,8 @@
 #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>
@@ -362,26 +364,29 @@
 asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
 {
 	struct task_struct *child;
-	struct user * dummy;
-	int i;
-
-	dummy = NULL;
+	struct user * dummy = NULL;
+	int i, ret;
 
+	lock_kernel();
+	ret = -EPERM;
 	if (request == PTRACE_TRACEME) {
 		/* are we already being traced? */
 		if (current->flags & PF_PTRACED)
-			return -EPERM;
+			goto out;
 		/* set the ptrace bit in the process flags. */
 		current->flags |= PF_PTRACED;
-		return 0;
+		ret = 0;
+		goto out;
 	}
 	if (pid == 1)		/* you may not mess with init */
-		return -EPERM;
+		goto out;
+	ret = -ESRCH;
 	if (!(child = get_task(pid)))
-		return -ESRCH;
+		goto out;
+	ret = -EPERM;
 	if (request == PTRACE_ATTACH) {
 		if (child == current)
-			return -EPERM;
+			goto out;
 		if ((!child->dumpable ||
 		    (current->uid != child->euid) ||
 		    (current->uid != child->suid) ||
@@ -389,10 +394,10 @@
 	 	    (current->gid != child->egid) ||
 	 	    (current->gid != child->sgid) ||
 	 	    (current->gid != child->gid)) && !suser())
-			return -EPERM;
+			goto out;
 		/* the same process cannot be attached many times */
 		if (child->flags & PF_PTRACED)
-			return -EPERM;
+			goto out;
 		child->flags |= PF_PTRACED;
 		if (child->p_pptr != current) {
 			REMOVE_LINKS(child);
@@ -400,37 +405,39 @@
 			SET_LINKS(child);
 		}
 		send_sig(SIGSTOP, child, 1);
-		return 0;
+		ret = 0;
+		goto out;
 	}
+	ret = -ESRCH;
 	if (!(child->flags & PF_PTRACED))
-		return -ESRCH;
+		goto out;
 	if (child->state != TASK_STOPPED) {
 		if (request != PTRACE_KILL)
-			return -ESRCH;
+			goto out;
 	}
 	if (child->p_pptr != current)
-		return -ESRCH;
+		goto out;
 
 	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 res;
 
-			res = read_long(child, addr, &tmp);
-			if (res < 0)
-				return res;
-			return put_user(tmp,(unsigned long *) data);
+			ret = read_long(child, addr, &tmp);
+			if (ret >= 0)
+				ret = put_user(tmp,(unsigned long *) data);
+			goto out;
 		}
 
 	/* read the word at location addr in the USER area. */
 		case PTRACE_PEEKUSR: {
 			unsigned long tmp;
 
+			ret = -EIO;
 			if ((addr & 3) || addr < 0 || 
 			    addr > sizeof(struct user) - 3)
-				return -EIO;
+				goto out;
 
 			tmp = 0;  /* Default return condition */
 			if(addr < 17*sizeof(long))
@@ -441,21 +448,26 @@
 				addr = addr >> 2;
 				tmp = child->debugreg[addr];
 			};
-			return put_user(tmp,(unsigned long *) data);
+			ret = put_user(tmp,(unsigned long *) data);
+			goto out;
 		}
 
       /* 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:
-			return write_long(child,addr,data);
+			ret = write_long(child,addr,data);
+			goto out;
 
 		case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
+			ret = -EIO;
 			if ((addr & 3) || addr < 0 || 
 			    addr > sizeof(struct user) - 3)
-				return -EIO;
+				goto out;
 
-			if (addr < 17*sizeof(long))
-				return putreg(child, addr, data);
+			if (addr < 17*sizeof(long)) {
+				ret = putreg(child, addr, data);
+				goto out;
+			}
 
 		  /* We need to be very careful here.  We implicitly
 		     want to modify a portion of the task_struct, and we
@@ -470,26 +482,30 @@
 			  if(addr < (long) &dummy->u_debugreg[4] &&
 			     ((unsigned long) data) >= 0xbffffffd) return -EIO;
 			  
+			  ret = -EIO;
 			  if(addr == (long) &dummy->u_debugreg[7]) {
 				  data &= ~DR_CONTROL_RESERVED;
 				  for(i=0; i<4; i++)
 					  if ((0x5f54 >> ((data >> (16 + 4*i)) & 0xf)) & 1)
-						  return -EIO;
+						  goto out;
 			  };
 
 			  addr -= (long) &dummy->u_debugreg;
 			  addr = addr >> 2;
 			  child->debugreg[addr] = data;
-			  return 0;
+			  ret = 0;
+			  goto out;
 		  };
-		  return -EIO;
+		  ret = -EIO;
+		  goto out;
 
 		case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 		case PTRACE_CONT: { /* restart after signal. */
 			long tmp;
 
+			ret = -EIO;
 			if ((unsigned long) data > NSIG)
-				return -EIO;
+				goto out;
 			if (request == PTRACE_SYSCALL)
 				child->flags |= PF_TRACESYS;
 			else
@@ -499,7 +515,8 @@
 	/* make sure the single step bit is not set. */
 			tmp = get_stack_long(child, EFL_OFFSET) & ~TRAP_FLAG;
 			put_stack_long(child, EFL_OFFSET,tmp);
-			return 0;
+			ret = 0;
+			goto out;
 		}
 
 /*
@@ -510,35 +527,39 @@
 		case PTRACE_KILL: {
 			long tmp;
 
+			ret = 0;
 			if (child->state == TASK_ZOMBIE)	/* already dead */
-				return 0;
+				goto out;
 			wake_up_process(child);
 			child->exit_code = SIGKILL;
 	/* make sure the single step bit is not set. */
 			tmp = get_stack_long(child, EFL_OFFSET) & ~TRAP_FLAG;
 			put_stack_long(child, EFL_OFFSET, tmp);
-			return 0;
+			goto out;
 		}
 
 		case PTRACE_SINGLESTEP: {  /* set the trap flag. */
 			long tmp;
 
+			ret = -EIO;
 			if ((unsigned long) data > NSIG)
-				return -EIO;
+				goto out;
 			child->flags &= ~PF_TRACESYS;
 			tmp = get_stack_long(child, EFL_OFFSET) | TRAP_FLAG;
 			put_stack_long(child, EFL_OFFSET, tmp);
 			wake_up_process(child);
 			child->exit_code = data;
 	/* give it a chance to run. */
-			return 0;
+			ret = 0;
+			goto out;
 		}
 
 		case PTRACE_DETACH: { /* detach a process that was attached. */
 			long tmp;
 
+			ret = -EIO;
 			if ((unsigned long) data > NSIG)
-				return -EIO;
+				goto out;
 			child->flags &= ~(PF_PTRACED|PF_TRACESYS);
 			wake_up_process(child);
 			child->exit_code = data;
@@ -548,19 +569,25 @@
 			/* make sure the single step bit is not set. */
 			tmp = get_stack_long(child, EFL_OFFSET) & ~TRAP_FLAG;
 			put_stack_long(child, EFL_OFFSET, tmp);
-			return 0;
+			ret = 0;
+			goto out;
 		}
 
 		default:
-			return -EIO;
+			ret = -EIO;
+			goto out;
 	}
+out:
+	unlock_kernel();
+	return ret;
 }
 
 asmlinkage void syscall_trace(void)
 {
+	lock_kernel();
 	if ((current->flags & (PF_PTRACED|PF_TRACESYS))
 			!= (PF_PTRACED|PF_TRACESYS))
-		return;
+		goto out;
 	current->exit_code = SIGTRAP;
 	current->state = TASK_STOPPED;
 	notify_parent(current);
@@ -573,4 +600,6 @@
 	if (current->exit_code)
 		current->signal |= (1 << (current->exit_code - 1));
 	current->exit_code = 0;
+out:
+	unlock_kernel();
 }