printk() format %pS wrong symbol

[Valentin Vidić]

On Tue, Jul 07, 2020 at 08:39:27PM +0200, Valentin Vidić wrote:
> From what I understand print_backtrace() tries to handle the case when
> call is the last instruction in a function:
> 
> func1: ...
>        ...
>        ...
>        call noret_func3()
> func2: ...
>        ...
>        ...
> 
> Return value on the stack points to the next instruction after the call. 
> But in this case a new function already starts on that address so they
> add -1 to make the address point back to func1.
> 
> Not sure what goes wrong in your case, could you share an example and
> more info on the port?

This could go wrong if the return address on the stack points to the
first instruction of ret_for_syscall:

kernel_init:     ...
                 ...
                 ...
ret_for_syscall: ... <-- return address
                 ...
                 ...

In this case kernel_init would be printed instead. Not sure how this
address would end up on the stack unless ret_for_syscall is placed
directly on the stack for some reason?

-- 
Valentin