Re: [PATCH 1/4] counter: Adjust final parameter type in function and signal callbacks

On Wed, Nov 02, 2022 at 01:23:51PM -0700, Nathan Chancellor wrote:

Right, I am not the biggest fan of this change myself and it is entirely
possible that I am misreading the warnings from the commit message but I
do not see how

        comp_node.comp.signal_u32_read = counter->ops->signal_read;

and

        comp_node.comp.count_u32_read = counter->ops->function_read;

in counter_add_watch(),

        comp.signal_u32_read = counter->ops->signal_read;

in counter_signal_attrs_create(), and

        comp.count_u32_read = counter->ops->function_read;
        comp.count_u32_write = counter->ops->function_write;

in counter_count_attrs_create() are currently safe under kCFI, since the
final parameter type of the prototypes in 'struct counter_ops' does not
match the final parameter type of the prototypes in 'struct
counter_comp'. I would expect the indirect calls in counter_get_data()
and counter_comp_u32_show() to fail currently.

Ah! Thank you -- those were the places I couldn't find.

-- 
Kees Cook

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