1. 22 Mar, 2013 1 commit
  2. 04 Nov, 2012 1 commit
    • Jan Beulich's avatar
      xen/hypercall: fix hypercall fallback code for very old hypervisors · cf47a83f
      Jan Beulich authored
      While copying the argument structures in HYPERVISOR_event_channel_op()
      and HYPERVISOR_physdev_op() into the local variable is sufficiently
      safe even if the actual structure is smaller than the container one,
      copying back eventual output values the same way isn't: This may
      collide with on-stack variables (particularly "rc") which may change
      between the first and second memcpy() (i.e. the second memcpy() could
      discard that change).
      
      Move the fallback code into out-of-line functions, and handle all of
      the operations known by this old a hypervisor individually: Some don't
      require copying back anything at all, and for the rest use the
      individual argument structures' sizes rather than the container's.
      Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
      [v2: Reduce #define/#undef usage in HYPERVISOR_physdev_op_compat().]
      [v3: Fix compile errors when modules use said hypercalls]
      [v4: Add xen_ prefix to the HYPERCALL_..]
      [v5: Alter the name and only EXPORT_SYMBOL_GPL one of them]
      Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      cf47a83f