On 2/11/21 8:42 PM, Nathan Chancellor wrote:
> fw_cfg_showrev() is called by an indirect call in kobj_attr_show(),
> which violates clang's CFI checking because fw_cfg_showrev()'s second
> parameter is 'struct attribute', whereas the ->show() member of 'struct
> kobj_structure' expects the second parameter to be of type 'struct
> kobj_attribute'.
>
> $ cat /sys/firmware/qemu_fw_cfg/rev
> 3
>
> $ dmesg | grep "CFI failure"
> [ 26.016832] CFI failure (target: fw_cfg_showrev+0x0/0x8):
>
> Fix this by converting fw_cfg_rev_attr to 'struct kobj_attribute' where
> this would have been caught automatically by the incompatible pointer
> types compiler warning. Update fw_cfg_showrev() accordingly.
>
> Fixes: 75f3e8e47f38 ("firmware: introduce sysfs driver for QEMU's fw_cfg
> device")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1299
> Signed-off-by: Nathan Chancellor <nat...@kernel.org>
> ---
> drivers/firmware/qemu_fw_cfg.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
