adb push Permission denied

在adb shell下执行如下步骤：

1 获取用户权限

shell@android:/ $ su

2 查看mount信息

/ # mount

rootfs / rootfs ro,relatime 0 0
tmpfs /dev tmpfs rw,nosuid,relatime,mode=755 0 0
devpts /dev/pts devpts rw,relatime,mode=600 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
tmpfs /mnt/asec tmpfs rw,relatime,mode=755,gid=1000 0 0
tmpfs /mnt/obb tmpfs rw,relatime,mode=755,gid=1000 0 0
/dev/block/mtdblock8 /system yaffs2 ro,relatime 0 0
/dev/block/mtdblock10 /data yaffs2 rw,nosuid,nodev,relatime 0 0
/dev/block/mtdblock9 /cache yaffs2 rw,nosuid,nodev,relatime 0 0
/dev/fuse /mnt/local fuse rw,nosuid,nodev,relatime,user_id=1023,group_id=1023,de
fault_permissions,allow_other 0 0
none /proc/bus/usb usbfs rw,relatime 0 0

3 重新mount

/ # mount -o rw,remount -t yaffs2 /dev/block/mtdblock8 /system

4 更改权限

/ # chmod 777 /system/