Re: [PATCH v2] efi_loader: fix missing EFI_EXIT in efi_disconnect_controller

["Vincent Stehlé" <vincent.stehle@arm.com>]

On Fri, Jun 19, 2026 at 11:22:22AM +0300, Ilias Apalodimas wrote:
> Thanks Vincent, 
> On Thu, 18 Jun 2026 at 19:09, Vincent Stehlé <[1]vincent.stehle@arm.com> wrote:
> 
> > We are missing a call to EFI_EXIT() when returning from
> > efi_disconnect_controller(), which we need after having called EFI_ENTRY().
> 
> > Fix this by jumping to the common error path, which does call EFI_EXIT().
> 
> > Even though the common error path may try to free child_handle_buffer, this
> > cannot harm in our case as it always NULL.
> 
> > This is inspired by a barebox fix. [1]
> 
> There's more in that link and some of them are still valid. Do you plan to send
> more?

Hi Ilias,

I am trying to, but... I have looked at the barebox fixes and I think they
necessitate a triaging and verification effort.

- Some fixes are not applicable to U-Boot (e.g. [1]).
- Some fixes look applicable to U-Boot but in fact are not (I tried to reproduce
  [2] on U-Boot with a unit test for example, but I could not make the test
  fail).
- Some fixes look applicable but I would like to verify completeness (I am
  looking at [3] for example).
- And last but not least, some fixes are difficult for me to review.

This makes me think that we should try to create a "reproducer" in
lib/efi_selftest/ systematically for each fix to the EFI Loader.

Best regards,
Vincent.

[1] https://git.pengutronix.de/cgit/barebox/commit/efi/loader?id=f34f05ff87cf3a0a9f7345227f9a080ddcf3ec48
[2] https://git.pengutronix.de/cgit/barebox/commit/efi/loader?id=cbe4bd04edec9c1d3c843fcc22e1a7ae5c9c4551
[3] https://git.pengutronix.de/cgit/barebox/commit/efi/loader?id=4e9944e5cd1170cb5c54f97f4e12ddeccba53e55

> 
> > Link:
> > [2]https://git.pengutronix.de/cgit/barebox/commit/?id=080db65e39a877b000baaf843c997a69821dfe69
> > [1]
> > Fixes: 314bed6c854e ("efi_loader: fix DisconnectController() for sole child")
> > Signed-off-by: Vincent Stehlé <[3]vincent.stehle@arm.com>
> > Cc: Heinrich Schuchardt <[4]xypron.glpk@gmx.de>
> > Cc: Ilias Apalodimas <[5]ilias.apalodimas@linaro.org>
> > Cc: Tom Rini <[6]trini@konsulko.com>
> > ---
> 
> Reviewed-by: Ilias Apalodimas <[7]ilias.apalodimas@linaro.org>
>  
> 
> > Changes for v2:
> > - Drop the return and jump to the common error path with a goto instead
> 
> >  lib/efi_loader/efi_boottime.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> > diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> > index de57823bd44..bcb01c92cf4 100644
> > --- a/lib/efi_loader/efi_boottime.c
> > +++ b/lib/efi_loader/efi_boottime.c
> > @@ -3895,7 +3895,7 @@ efi_status_t EFIAPI efi_disconnect_controller(
> >                                       &number_of_children,
> >                                       &child_handle_buffer);
> >         if (r != EFI_SUCCESS)
> > -               return r;
> > +               goto out;
> >         sole_child = (number_of_children == 1);
> 
> >         if (child_handle) {
> > --
> > 2.53.0
> 
> References
> 
>    Visible links
>    1. mailto:vincent.stehle@arm.com
>    2. https://git.pengutronix.de/cgit/barebox/commit/?id=080db65e39a877b000baaf843c997a69821dfe69
>    3. mailto:vincent.stehle@arm.com
>    4. mailto:xypron.glpk@gmx.de
>    5. mailto:ilias.apalodimas@linaro.org
>    6. mailto:trini@konsulko.com
>    7. mailto:ilias.apalodimas@linaro.org

-- 
Vincent.