[PATCH 4/6] epoll: deduplicate compat logic

[Willem de Bruijn]

From: Willem de Bruijn <will...@google.com>

Apply the same compat deduplication strategy to epoll that was
previously applied to (p)select and ppoll.

Make do_epoll_wait handle both variants of sigmask. This removes
the need for near duplicate do_compat_epoll_pwait.

Signed-off-by: Willem de Bruijn <will...@google.com>
---
 fs/eventpoll.c | 38 +++++++++-----------------------------
 1 file changed, 9 insertions(+), 29 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index a829af074eb5..c9dcffba2da1 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -2239,7 +2239,7 @@ SYSCALL_DEFINE4(epoll_wait, int, epfd, struct epoll_event 
__user *, events,
  */
 static int do_epoll_pwait(int epfd, struct epoll_event __user *events,
                          int maxevents, struct timespec64 *to,
-                         const sigset_t __user *sigmask, size_t sigsetsize)
+                         const void __user *sigmask, size_t sigsetsize)
 {
        int error;
 
@@ -2247,7 +2247,10 @@ static int do_epoll_pwait(int epfd, struct epoll_event 
__user *events,
         * If the caller wants a certain signal mask to be set during the wait,
         * we apply it here.
         */
-       error = set_user_sigmask(sigmask, sigsetsize);
+       if (!in_compat_syscall())
+               error = set_user_sigmask(sigmask, sigsetsize);
+       else
+               error = set_compat_user_sigmask(sigmask, sigsetsize);
        if (error)
                return error;
 
@@ -2288,28 +2291,6 @@ SYSCALL_DEFINE6(epoll_pwait2, int, epfd, struct 
epoll_event __user *, events,
 }
 
 #ifdef CONFIG_COMPAT
-static int do_compat_epoll_pwait(int epfd, struct epoll_event __user *events,
-                                int maxevents, struct timespec64 *timeout,
-                                const compat_sigset_t __user *sigmask,
-                                compat_size_t sigsetsize)
-{
-       long err;
-
-       /*
-        * If the caller wants a certain signal mask to be set during the wait,
-        * we apply it here.
-        */
-       err = set_compat_user_sigmask(sigmask, sigsetsize);
-       if (err)
-               return err;
-
-       err = do_epoll_wait(epfd, events, maxevents, timeout);
-
-       restore_saved_sigmask_unless(err == -EINTR);
-
-       return err;
-}
-
 COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd,
                       struct epoll_event __user *, events,
                       int, maxevents, int, timeout,
@@ -2318,9 +2299,9 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd,
 {
        struct timespec64 to;
 
-       return do_compat_epoll_pwait(epfd, events, maxevents,
-                                    ep_timeout_to_timespec(&to, timeout),
-                                    sigmask, sigsetsize);
+       return do_epoll_pwait(epfd, events, maxevents,
+                             ep_timeout_to_timespec(&to, timeout),
+                             sigmask, sigsetsize);
 }
 
 COMPAT_SYSCALL_DEFINE6(epoll_pwait2, int, epfd,
@@ -2340,8 +2321,7 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait2, int, epfd,
                        return -EINVAL;
        }
 
-       return do_compat_epoll_pwait(epfd, events, maxevents, to,
-                                    sigmask, sigsetsize);
+       return do_epoll_pwait(epfd, events, maxevents, to, sigmask, sigsetsize);
 }
 
 #endif
-- 
2.30.0.284.gd98b1dd5eaa7-goog