lkml.org 
[lkml]   [2021]   [Feb]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] qemu_fw_cfg: Make fw_cfg_rev_attr a proper kobj_attribute
Did this happen to get picked up already? EOM

On Thu, Feb 11, 2021 at 11:43 AM Nathan Chancellor <nathan@kernel.org> 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 <nathan@kernel.org>
> ---
> drivers/firmware/qemu_fw_cfg.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
> index 0078260fbabe..172c751a4f6c 100644
> --- a/drivers/firmware/qemu_fw_cfg.c
> +++ b/drivers/firmware/qemu_fw_cfg.c
> @@ -299,15 +299,13 @@ static int fw_cfg_do_platform_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static ssize_t fw_cfg_showrev(struct kobject *k, struct attribute *a, char *buf)
> +static ssize_t fw_cfg_showrev(struct kobject *k, struct kobj_attribute *a,
> + char *buf)
> {
> return sprintf(buf, "%u\n", fw_cfg_rev);
> }
>
> -static const struct {
> - struct attribute attr;
> - ssize_t (*show)(struct kobject *k, struct attribute *a, char *buf);
> -} fw_cfg_rev_attr = {
> +static const struct kobj_attribute fw_cfg_rev_attr = {
> .attr = { .name = "rev", .mode = S_IRUSR },
> .show = fw_cfg_showrev,
> };
>
> base-commit: 92bf22614b21a2706f4993b278017e437f7785b3
> --
> 2.30.1
>
> --
> You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20210211194258.4137998-1-nathan%40kernel.org.



--
Thanks,
~Nick Desaulniers

\
 
 \ /
  Last update: 2021-02-22 20:06    [W:0.072 / U:24.788 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site