1 files changed, 25 insertions, 41 deletions

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 00ab2ca5ed11..ee8d49b9c309 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -231,26 +231,22 @@ bool ptrace_may_access(struct task_struct *task, unsigned int mode)
 }
 
 static int ptrace_attach(struct task_struct *task, long request,
+			 unsigned long addr,
 			 unsigned long flags)
 {
 	bool seize = (request == PTRACE_SEIZE);
 	int retval;
 
-	/*
-	 * SEIZE will enable new ptrace behaviors which will be implemented
-	 * gradually.  SEIZE_DEVEL is used to prevent applications
-	 * expecting full SEIZE behaviors trapping on kernel commits which
-	 * are still in the process of implementing them.
-	 *
-	 * Only test programs for new ptrace behaviors being implemented
-	 * should set SEIZE_DEVEL.  If unset, SEIZE will fail with -EIO.
-	 *
-	 * Once SEIZE behaviors are completely implemented, this flag and
-	 * the following test will be removed.
-	 */
 	retval = -EIO;
-	if (seize && !(flags & PTRACE_SEIZE_DEVEL))
-		goto out;
+	if (seize) {
+		if (addr != 0)
+			goto out;
+		if (flags & ~(unsigned long)PTRACE_O_MASK)
+			goto out;
+		flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
+	} else {
+		flags = PT_PTRACED;
+	}
 
 	audit_ptrace(task);
 
@@ -262,7 +258,7 @@ static int ptrace_attach(struct task_struct *task, long request,
 
 	/*
 	 * Protect exec's credential calculations against our interference;
-	 * interference; SUID, SGID and LSM creds get determined differently
+	 * SUID, SGID and LSM creds get determined differently
 	 * under ptrace.
 	 */
 	retval = -ERESTARTNOINTR;
@@ -282,11 +278,11 @@ static int ptrace_attach(struct task_struct *task, long request,
 	if (task->ptrace)
 		goto unlock_tasklist;
 
-	task->ptrace = PT_PTRACED;
 	if (seize)
-		task->ptrace |= PT_SEIZED;
+		flags |= PT_SEIZED;
 	if (ns_capable(task_user_ns(task), CAP_SYS_PTRACE))
-		task->ptrace |= PT_PTRACE_CAP;
+		flags |= PT_PTRACE_CAP;
+	task->ptrace = flags;
 
 	__ptrace_link(task, current);
 
@@ -528,30 +524,18 @@ int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long ds
 
 static int ptrace_setoptions(struct task_struct *child, unsigned long data)
 {
-	child->ptrace &= ~PT_TRACE_MASK;
+	unsigned flags;
 
-	if (data & PTRACE_O_TRACESYSGOOD)
-		child->ptrace |= PT_TRACESYSGOOD;
-
-	if (data & PTRACE_O_TRACEFORK)
-		child->ptrace |= PT_TRACE_FORK;
-
-	if (data & PTRACE_O_TRACEVFORK)
-		child->ptrace |= PT_TRACE_VFORK;
-
-	if (data & PTRACE_O_TRACECLONE)
-		child->ptrace |= PT_TRACE_CLONE;
-
-	if (data & PTRACE_O_TRACEEXEC)
-		child->ptrace |= PT_TRACE_EXEC;
-
-	if (data & PTRACE_O_TRACEVFORKDONE)
-		child->ptrace |= PT_TRACE_VFORK_DONE;
+	if (data & ~(unsigned long)PTRACE_O_MASK)
+		return -EINVAL;
 
-	if (data & PTRACE_O_TRACEEXIT)
-		child->ptrace |= PT_TRACE_EXIT;
+	/* Avoid intermediate state when all opts are cleared */
+	flags = child->ptrace;
+	flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
+	flags |= (data << PT_OPT_FLAG_SHIFT);
+	child->ptrace = flags;
 
-	return (data & ~PTRACE_O_MASK) ? -EINVAL : 0;
+	return 0;
 }
 
 static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info)
@@ -891,7 +875,7 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
 	}
 
 	if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
-		ret = ptrace_attach(child, request, data);
+		ret = ptrace_attach(child, request, addr, data);
 		/*
 		 * Some architectures need to do book-keeping after
 		 * a ptrace attach.
@@ -1034,7 +1018,7 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid,
 	}
 
 	if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
-		ret = ptrace_attach(child, request, data);
+		ret = ptrace_attach(child, request, addr, data);
 		/*
 		 * Some architectures need to do book-keeping after
 		 * a ptrace attach.