From 227f02143f269493543faf6908318c17abd725cd Mon Sep 17 00:00:00 2001
From: Peter Maydell <peter.maydell@linaro.org>
Date: Mon, 6 Jun 2016 19:58:11 +0100
Subject: [PATCH] linux-user: Use safe_syscall wrapper for epoll_wait syscalls

Use the safe_syscall wrapper for epoll_wait and epoll_pwait syscalls.

Since we now directly use the host epoll_pwait syscall for both
epoll_wait and epoll_pwait, we don't need the configure machinery
to check whether glibc supports epoll_pwait(). (The kernel has
supported the syscall since 2.6.19 so we can assume it's always there.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
---
 configure            | 21 ++-------------------
 linux-user/syscall.c | 18 ++++++++++--------
 2 files changed, 12 insertions(+), 27 deletions(-)

diff --git a/configure b/configure
index d1dbc4b099..e995ddd7c9 100755
--- a/configure
+++ b/configure
@@ -3798,8 +3798,8 @@ if compile_prog "" "" ; then
   epoll=yes
 fi
 
-# epoll_create1 and epoll_pwait are later additions
-# so we must check separately for their presence
+# epoll_create1 is a later addition
+# so we must check separately for its presence
 epoll_create1=no
 cat > $TMPC << EOF
 #include <sys/epoll.h>
@@ -3821,20 +3821,6 @@ if compile_prog "" "" ; then
   epoll_create1=yes
 fi
 
-epoll_pwait=no
-cat > $TMPC << EOF
-#include <sys/epoll.h>
-
-int main(void)
-{
-    epoll_pwait(0, 0, 0, 0, 0);
-    return 0;
-}
-EOF
-if compile_prog "" "" ; then
-  epoll_pwait=yes
-fi
-
 # check for sendfile support
 sendfile=no
 cat > $TMPC << EOF
@@ -5125,9 +5111,6 @@ fi
 if test "$epoll_create1" = "yes" ; then
   echo "CONFIG_EPOLL_CREATE1=y" >> $config_host_mak
 fi
-if test "$epoll_pwait" = "yes" ; then
-  echo "CONFIG_EPOLL_PWAIT=y" >> $config_host_mak
-fi
 if test "$sendfile" = "yes" ; then
   echo "CONFIG_SENDFILE=y" >> $config_host_mak
 fi
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 8bb9adff1a..a193849494 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -699,6 +699,9 @@ safe_syscall6(int, pselect6, int, nfds, fd_set *, readfds, fd_set *, writefds, \
 safe_syscall5(int, ppoll, struct pollfd *, ufds, unsigned int, nfds,
               struct timespec *, tsp, const sigset_t *, sigmask,
               size_t, sigsetsize)
+safe_syscall6(int, epoll_pwait, int, epfd, struct epoll_event *, events,
+              int, maxevents, int, timeout, const sigset_t *, sigmask,
+              size_t, sigsetsize)
 safe_syscall6(int,futex,int *,uaddr,int,op,int,val, \
               const struct timespec *,timeout,int *,uaddr2,int,val3)
 safe_syscall2(int, rt_sigsuspend, sigset_t *, newset, size_t, sigsetsize)
@@ -10835,14 +10838,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
     }
 #endif
 
-#if defined(TARGET_NR_epoll_pwait) && defined(CONFIG_EPOLL_PWAIT)
-#define IMPLEMENT_EPOLL_PWAIT
-#endif
-#if defined(TARGET_NR_epoll_wait) || defined(IMPLEMENT_EPOLL_PWAIT)
+#if defined(TARGET_NR_epoll_wait) || defined(TARGET_NR_epoll_pwait)
 #if defined(TARGET_NR_epoll_wait)
     case TARGET_NR_epoll_wait:
 #endif
-#if defined(IMPLEMENT_EPOLL_PWAIT)
+#if defined(TARGET_NR_epoll_pwait)
     case TARGET_NR_epoll_pwait:
 #endif
     {
@@ -10861,7 +10861,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
         ep = alloca(maxevents * sizeof(struct epoll_event));
 
         switch (num) {
-#if defined(IMPLEMENT_EPOLL_PWAIT)
+#if defined(TARGET_NR_epoll_pwait)
         case TARGET_NR_epoll_pwait:
         {
             target_sigset_t *target_set;
@@ -10880,13 +10880,15 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
                 set = NULL;
             }
 
-            ret = get_errno(epoll_pwait(epfd, ep, maxevents, timeout, set));
+            ret = get_errno(safe_epoll_pwait(epfd, ep, maxevents, timeout,
+                                             set, SIGSET_T_SIZE));
             break;
         }
 #endif
 #if defined(TARGET_NR_epoll_wait)
         case TARGET_NR_epoll_wait:
-            ret = get_errno(epoll_wait(epfd, ep, maxevents, timeout));
+            ret = get_errno(safe_epoll_pwait(epfd, ep, maxevents, timeout,
+                                             NULL, 0));
             break;
 #endif
         default: