pids: introduce find_get_task_by_vpid() helper
There are several functions that do find_task_by_vpid() followed by
get_task_struct(). We can use a helper function instead.
Link: http://lkml.kernel.org/r/1509602027-11337-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 5e1d713..21fec73 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -1103,21 +1103,6 @@ int ptrace_request(struct task_struct *child, long request,
return ret;
}
-static struct task_struct *ptrace_get_task_struct(pid_t pid)
-{
- struct task_struct *child;
-
- rcu_read_lock();
- child = find_task_by_vpid(pid);
- if (child)
- get_task_struct(child);
- rcu_read_unlock();
-
- if (!child)
- return ERR_PTR(-ESRCH);
- return child;
-}
-
#ifndef arch_ptrace_attach
#define arch_ptrace_attach(child) do { } while (0)
#endif
@@ -1135,9 +1120,9 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
goto out;
}
- child = ptrace_get_task_struct(pid);
- if (IS_ERR(child)) {
- ret = PTR_ERR(child);
+ child = find_get_task_by_vpid(pid);
+ if (!child) {
+ ret = -ESRCH;
goto out;
}
@@ -1281,9 +1266,9 @@ COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
goto out;
}
- child = ptrace_get_task_struct(pid);
- if (IS_ERR(child)) {
- ret = PTR_ERR(child);
+ child = find_get_task_by_vpid(pid);
+ if (!child) {
+ ret = -ESRCH;
goto out;
}
