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.