[PATCH] efi_selftest: fix guid comparison

[PATCH] efi_selftest: fix guid comparison

[Vincent Stehlé]

The `loaded image' efi selftest is comparing protocol GUIDs with the wrong
polarity.
This can be verified on the sandbox, where two protocols GUIDs are
retrieved by the test from the image handle in the following order:

1. Loaded Image Device Path Protocol GUID
2. Loaded Image Protocol GUID

The test matches on the first GUID, while it is in fact looking for the
second one; fix the comparison polarity.

While at it, use guidcmp() instead of memcmp() to spare the size parameter,
and use the Loaded Image Protocol GUID definition from efi_api.h instead or
redefining it locally.

Fixes: efe79a7c0de0 ("efi_selftest: test for loaded image protocol")
Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Alexander Graf <agraf@suse.de>
---
 lib/efi_selftest/efi_selftest_loaded_image.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/lib/efi_selftest/efi_selftest_loaded_image.c b/lib/efi_selftest/efi_selftest_loaded_image.c
index 5889ab12617..48890a66db7 100644
--- a/lib/efi_selftest/efi_selftest_loaded_image.c
+++ b/lib/efi_selftest/efi_selftest_loaded_image.c
@@ -9,9 +9,7 @@
 
 #include <efi_selftest.h>
 
-static efi_guid_t loaded_image_protocol_guid =
-	EFI_GUID(0x5b1b31a1, 0x9562, 0x11d2,
-		 0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b);
+static efi_guid_t loaded_image_protocol_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID;
 static struct efi_boot_services *boottime;
 efi_handle_t image_handle;
 
@@ -60,8 +58,7 @@ static int execute(void)
 	efi_st_printf("%u protocols installed on image handle\n",
 		      (unsigned int)protocol_buffer_count);
 	for (i = 0; i < protocol_buffer_count; ++i) {
-		if (memcmp(protocol_buffer[i], &loaded_image_protocol_guid,
-			   sizeof(efi_guid_t)))
+		if (!guidcmp(protocol_buffer[i], &loaded_image_protocol_guid))
 			found = true;
 	}
 	if (!found) {
-- 
2.53.0

Re: [PATCH] efi_selftest: fix guid comparison

[Ilias Apalodimas]

On Thu, 11 Jun 2026 at 12:29, Vincent Stehlé <vincent.stehle@arm.com> wrote:
>
> The `loaded image' efi selftest is comparing protocol GUIDs with the wrong
> polarity.
> This can be verified on the sandbox, where two protocols GUIDs are
> retrieved by the test from the image handle in the following order:
>
> 1. Loaded Image Device Path Protocol GUID
> 2. Loaded Image Protocol GUID
>
> The test matches on the first GUID, while it is in fact looking for the
> second one; fix the comparison polarity.
>
> While at it, use guidcmp() instead of memcmp() to spare the size parameter,
> and use the Loaded Image Protocol GUID definition from efi_api.h instead or
> redefining it locally.
>
> Fixes: efe79a7c0de0 ("efi_selftest: test for loaded image protocol")
> Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
> Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Alexander Graf <agraf@suse.de>
> ---

Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

>  lib/efi_selftest/efi_selftest_loaded_image.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/lib/efi_selftest/efi_selftest_loaded_image.c b/lib/efi_selftest/efi_selftest_loaded_image.c
> index 5889ab12617..48890a66db7 100644
> --- a/lib/efi_selftest/efi_selftest_loaded_image.c
> +++ b/lib/efi_selftest/efi_selftest_loaded_image.c
> @@ -9,9 +9,7 @@
>
>  #include <efi_selftest.h>
>
> -static efi_guid_t loaded_image_protocol_guid =
> -       EFI_GUID(0x5b1b31a1, 0x9562, 0x11d2,
> -                0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b);
> +static efi_guid_t loaded_image_protocol_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID;
>  static struct efi_boot_services *boottime;
>  efi_handle_t image_handle;
>
> @@ -60,8 +58,7 @@ static int execute(void)
>         efi_st_printf("%u protocols installed on image handle\n",
>                       (unsigned int)protocol_buffer_count);
>         for (i = 0; i < protocol_buffer_count; ++i) {
> -               if (memcmp(protocol_buffer[i], &loaded_image_protocol_guid,
> -                          sizeof(efi_guid_t)))
> +               if (!guidcmp(protocol_buffer[i], &loaded_image_protocol_guid))
>                         found = true;
>         }
>         if (!found) {
> --
> 2.53.0
>

Re: [PATCH] efi_selftest: fix guid comparison

[Heinrich Schuchardt]

On 6/11/26 11:29, Vincent Stehlé wrote:
> The `loaded image' efi selftest is comparing protocol GUIDs with the wrong
> polarity.
> This can be verified on the sandbox, where two protocols GUIDs are
> retrieved by the test from the image handle in the following order:
> 
> 1. Loaded Image Device Path Protocol GUID
> 2. Loaded Image Protocol GUID
> 
> The test matches on the first GUID, while it is in fact looking for the
> second one; fix the comparison polarity.
> 
> While at it, use guidcmp() instead of memcmp() to spare the size parameter,
> and use the Loaded Image Protocol GUID definition from efi_api.h instead or
> redefining it locally.

Hello Vincent,

Thank you for catching the issue with the incorrect checkout for the 
Loaded Image Protocol.

We never use U-Boot library functions in efi_selftest to allow 
converting it into a standalone EFI application.

> 
> Fixes: efe79a7c0de0 ("efi_selftest: test for loaded image protocol")
> Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
> Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Alexander Graf <agraf@suse.de>
> ---
>   lib/efi_selftest/efi_selftest_loaded_image.c | 7 ++-----
>   1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/efi_selftest/efi_selftest_loaded_image.c b/lib/efi_selftest/efi_selftest_loaded_image.c
> index 5889ab12617..48890a66db7 100644
> --- a/lib/efi_selftest/efi_selftest_loaded_image.c
> +++ b/lib/efi_selftest/efi_selftest_loaded_image.c
> @@ -9,9 +9,7 @@
>   
>   #include <efi_selftest.h>
>   
> -static efi_guid_t loaded_image_protocol_guid =
> -	EFI_GUID(0x5b1b31a1, 0x9562, 0x11d2,
> -		 0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b);
> +static efi_guid_t loaded_image_protocol_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID;

This change is not described in the commit message. With the change we 
no longer test if efi_api.h has the correct value of the GUID. Why would 
you prefer this?

>   static struct efi_boot_services *boottime;
>   efi_handle_t image_handle;
>   
> @@ -60,8 +58,7 @@ static int execute(void)
>   	efi_st_printf("%u protocols installed on image handle\n",
>   		      (unsigned int)protocol_buffer_count);
>   	for (i = 0; i < protocol_buffer_count; ++i) {
> -		if (memcmp(protocol_buffer[i], &loaded_image_protocol_guid,
> -			   sizeof(efi_guid_t)))
> +		if (!guidcmp(protocol_buffer[i], &loaded_image_protocol_guid))
>   			found = true;

Changing the polarity is correct.

Best regards

Heinrich

>   	}
>   	if (!found) {

Re: [PATCH] efi_selftest: fix guid comparison

[Vincent Stehlé]

On Sat, Jun 13, 2026 at 10:22:39AM +0200, Heinrich Schuchardt wrote:
> On 6/11/26 11:29, Vincent Stehlé wrote:
> > The `loaded image' efi selftest is comparing protocol GUIDs with the wrong
> > polarity.
> > This can be verified on the sandbox, where two protocols GUIDs are
> > retrieved by the test from the image handle in the following order:
> > 
> > 1. Loaded Image Device Path Protocol GUID
> > 2. Loaded Image Protocol GUID
> > 
> > The test matches on the first GUID, while it is in fact looking for the
> > second one; fix the comparison polarity.
> > 
> > While at it, use guidcmp() instead of memcmp() to spare the size parameter,
> > and use the Loaded Image Protocol GUID definition from efi_api.h instead or
> > redefining it locally.
> 
> Hello Vincent,
> 
> Thank you for catching the issue with the incorrect checkout for the Loaded
> Image Protocol.

Hi Heinrich,

Thanks for your review.

> We never use U-Boot library functions in efi_selftest to allow converting it
> into a standalone EFI application.

Ok, this makes sense.
I will send a v2 keeping memcmp().

Note that I see 4 calls to guidcmp() in the selftests already. I think this does
not harm in practice because guidcmp() this is marked inline.
I also see more than a dozen places where memcmp() is used to compare GUIDs in
the selftests.

Would you like me to send another series to add a local definition of guidcmp()
for the selftests and convert all memcmp() when appropriate?
Or should I rather send a series converting all uses of guidcmp() in the
selftests to memcmp(), maybe?

> 
> > 
> > Fixes: efe79a7c0de0 ("efi_selftest: test for loaded image protocol")
> > Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
> > Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
> > Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
> > Cc: Tom Rini <trini@konsulko.com>
> > Cc: Alexander Graf <agraf@suse.de>
> > ---
> >   lib/efi_selftest/efi_selftest_loaded_image.c | 7 ++-----
> >   1 file changed, 2 insertions(+), 5 deletions(-)
> > 
> > diff --git a/lib/efi_selftest/efi_selftest_loaded_image.c b/lib/efi_selftest/efi_selftest_loaded_image.c
> > index 5889ab12617..48890a66db7 100644
> > --- a/lib/efi_selftest/efi_selftest_loaded_image.c
> > +++ b/lib/efi_selftest/efi_selftest_loaded_image.c
> > @@ -9,9 +9,7 @@
> >   #include <efi_selftest.h>
> > -static efi_guid_t loaded_image_protocol_guid =
> > -	EFI_GUID(0x5b1b31a1, 0x9562, 0x11d2,
> > -		 0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b);
> > +static efi_guid_t loaded_image_protocol_guid = EFI_LOADED_IMAGE_PROTOCOL_GUID;
> 
> This change is not described in the commit message.

It was a bit hidden, but it was mentioned:

  (..) and use the Loaded Image Protocol GUID definition from efi_api.h instead
  or redefining it locally.

> With the change we no
> longer test if efi_api.h has the correct value of the GUID. Why would you
> prefer this?

Sure, it could make sense to duplicate the GUIDs definitions for test purposes.
I will keep the definition as it is in the v2.

Note that we have a dozen places in the selftests using the common GUID
definitions from efi_api.h; shall I send a patch series to replace those?

Best regards,
Vincent.

> 
> >   static struct efi_boot_services *boottime;
> >   efi_handle_t image_handle;
> > @@ -60,8 +58,7 @@ static int execute(void)
> >   	efi_st_printf("%u protocols installed on image handle\n",
> >   		      (unsigned int)protocol_buffer_count);
> >   	for (i = 0; i < protocol_buffer_count; ++i) {
> > -		if (memcmp(protocol_buffer[i], &loaded_image_protocol_guid,
> > -			   sizeof(efi_guid_t)))
> > +		if (!guidcmp(protocol_buffer[i], &loaded_image_protocol_guid))
> >   			found = true;
> 
> Changing the polarity is correct.
> 
> Best regards
> 
> Heinrich
> 
> >   	}
> >   	if (!found) {

-- 
Vincent.

[PATCH v2] efi_selftest: fix guid comparison

[Vincent Stehlé]

The `loaded image' efi selftest is comparing protocol GUIDs with the wrong
polarity.
This can be verified on the sandbox, where two protocols GUIDs are
retrieved by the test from the image handle in the following order:

1. Loaded Image Device Path Protocol GUID
2. Loaded Image Protocol GUID

The test matches on the first GUID, while it is in fact looking for the
second one; fix the comparison polarity.

Fixes: efe79a7c0de0 ("efi_selftest: test for loaded image protocol")
Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Alexander Graf <agraf@csgraf.de>
---

Changes for v2:
- Continue using memcmp() and not guidcmp()
- Keep the Loaded Image Protocol GUID definition
- Fix Alexander's e-mail address

 lib/efi_selftest/efi_selftest_loaded_image.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/efi_selftest/efi_selftest_loaded_image.c b/lib/efi_selftest/efi_selftest_loaded_image.c
index 5889ab12617..e0668f60ebd 100644
--- a/lib/efi_selftest/efi_selftest_loaded_image.c
+++ b/lib/efi_selftest/efi_selftest_loaded_image.c
@@ -60,8 +60,8 @@ static int execute(void)
 	efi_st_printf("%u protocols installed on image handle\n",
 		      (unsigned int)protocol_buffer_count);
 	for (i = 0; i < protocol_buffer_count; ++i) {
-		if (memcmp(protocol_buffer[i], &loaded_image_protocol_guid,
-			   sizeof(efi_guid_t)))
+		if (!memcmp(protocol_buffer[i], &loaded_image_protocol_guid,
+			    sizeof(efi_guid_t)))
 			found = true;
 	}
 	if (!found) {
-- 
2.53.0