[Qemu-devel] [PULL 18/21] linux-user: Fix epoll on ARM hosts

[riku . voipio]

From: Alexander Graf <address@hidden>

The epoll emulation uses data structures without packing them, so the
compiler might choose to add padding inside.

This patch makes the most offending one (target_epoll_event) a packed
structure to make sure we don't pad it by accident. ARM would pad it,
so declare the padding mandatory for ARM targets.

This fixes i386-on-ARM epoll emulation for me.

Signed-off-by: Alexander Graf <address@hidden>
Signed-off-by: Riku Voipio <address@hidden>
---
 linux-user/syscall_defs.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index cb6341f..086fbff 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -2459,8 +2459,11 @@ typedef union target_epoll_data {
 
 struct target_epoll_event {
     uint32_t events;
+#ifdef TARGET_ARM
+    uint32_t __pad;
+#endif
     target_epoll_data_t data;
-};
+} QEMU_PACKED;
 #endif
 struct target_rlimit64 {
     uint64_t rlim_cur;
-- 
1.8.1.2