[PATCH v2] hw/acpi: fix breakage due to missing aml stub definitions when acpi is off

[PATCH v2] hw/acpi: fix breakage due to missing aml stub definitions when acpi is off

[Ani Sinha]

Some HW architectures do not support acpi and CONFIG_ACPI is off for them. For
those architectures, dummy stub function definitions help to resolve symbols.
This change adds couple of dummy stub definitions so that symbols for those can
be resolved and failures such as the following can be fixed for or1k targets.

Configuration:
qemu/build $ ../configure --enable-werror --disable-docs --disable-nettle \
             --enable-gcrypt --enable-fdt=system --enable-modules \
             --enable-trace-backends=dtrace --enable-docs \
	     --enable-vfio-user-server \
             --target-list="ppc64-softmmu or1k-softmmu s390x-softmmu x86_64-softmmu
 rx-softmmu sh4-softmmu nios2-softmmu"

actual failure:

qemu/build $ QTEST_QEMU_BINARY=./qemu-system-or1k  ./tests/qtest/qos-test

failed to open module:
/build/qemu/qemu/build/qemu-bundle/usr/local/lib64/qemu/hw-display-virtio-vga.so:
undefined symbol: aml_return
qemu-system-or1k: ../util/error.c:59: error_setv: Assertion `*errp ==
NULL' failed.
Broken pipe
../tests/qtest/libqtest.c:188: kill_qemu() detected QEMU death from
signal 6 (Aborted) (core dumped)
Aborted (core dumped)

CC: Bernhard Beschow <shentey@gmail.com>
Signed-off-by: Ani Sinha <ani@anisinha.ca>
---
 hw/acpi/aml-build-stub.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

changelog:
v2: cosmetic commit description format update.

diff --git a/hw/acpi/aml-build-stub.c b/hw/acpi/aml-build-stub.c
index 8d8ad1a314..89a8fec4af 100644
--- a/hw/acpi/aml-build-stub.c
+++ b/hw/acpi/aml-build-stub.c
@@ -26,6 +26,16 @@ void aml_append(Aml *parent_ctx, Aml *child)
 {
 }
 
+Aml *aml_return(Aml *val)
+{
+    return NULL;
+}
+
+Aml *aml_method(const char *name, int arg_count, AmlSerializeFlag sflag)
+{
+    return NULL;
+}
+
 Aml *aml_resource_template(void)
 {
     return NULL;
-- 
2.34.1

Re: [PATCH v2] hw/acpi: fix breakage due to missing aml stub definitions when acpi is off

[Philippe Mathieu-Daudé]

On 7/11/22 16:27, Ani Sinha wrote:
> Some HW architectures do not support acpi and CONFIG_ACPI is off for them. For
> those architectures, dummy stub function definitions help to resolve symbols.
> This change adds couple of dummy stub definitions so that symbols for those can
> be resolved and failures such as the following can be fixed for or1k targets.
> 
> Configuration:
> qemu/build $ ../configure --enable-werror --disable-docs --disable-nettle \
>               --enable-gcrypt --enable-fdt=system --enable-modules \
>               --enable-trace-backends=dtrace --enable-docs \
> 	     --enable-vfio-user-server \
>               --target-list="ppc64-softmmu or1k-softmmu s390x-softmmu x86_64-softmmu
>   rx-softmmu sh4-softmmu nios2-softmmu"
> 
> actual failure:
> 
> qemu/build $ QTEST_QEMU_BINARY=./qemu-system-or1k  ./tests/qtest/qos-test
> 
> failed to open module:
> /build/qemu/qemu/build/qemu-bundle/usr/local/lib64/qemu/hw-display-virtio-vga.so:
> undefined symbol: aml_return
> qemu-system-or1k: ../util/error.c:59: error_setv: Assertion `*errp ==
> NULL' failed.
> Broken pipe
> ../tests/qtest/libqtest.c:188: kill_qemu() detected QEMU death from
> signal 6 (Aborted) (core dumped)
> Aborted (core dumped)
> 
> CC: Bernhard Beschow <shentey@gmail.com>
> Signed-off-by: Ani Sinha <ani@anisinha.ca>
> ---
>   hw/acpi/aml-build-stub.c | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> changelog:
> v2: cosmetic commit description format update.
> 
> diff --git a/hw/acpi/aml-build-stub.c b/hw/acpi/aml-build-stub.c
> index 8d8ad1a314..89a8fec4af 100644
> --- a/hw/acpi/aml-build-stub.c
> +++ b/hw/acpi/aml-build-stub.c
> @@ -26,6 +26,16 @@ void aml_append(Aml *parent_ctx, Aml *child)
>   {
>   }
>   
> +Aml *aml_return(Aml *val)
> +{
> +    return NULL;

Can't return NULL, otherwise aml_append() will crash.

We just want the symbol to be defined, so instead:

       g_assert_not_reached();

> +}

Re: [PATCH v2] hw/acpi: fix breakage due to missing aml stub definitions when acpi is off

[Michael S. Tsirkin]

On Mon, Nov 07, 2022 at 06:08:49PM +0100, Philippe Mathieu-Daudé wrote:
> On 7/11/22 16:27, Ani Sinha wrote:
> > Some HW architectures do not support acpi and CONFIG_ACPI is off for them. For
> > those architectures, dummy stub function definitions help to resolve symbols.
> > This change adds couple of dummy stub definitions so that symbols for those can
> > be resolved and failures such as the following can be fixed for or1k targets.
> > 
> > Configuration:
> > qemu/build $ ../configure --enable-werror --disable-docs --disable-nettle \
> >               --enable-gcrypt --enable-fdt=system --enable-modules \
> >               --enable-trace-backends=dtrace --enable-docs \
> > 	     --enable-vfio-user-server \
> >               --target-list="ppc64-softmmu or1k-softmmu s390x-softmmu x86_64-softmmu
> >   rx-softmmu sh4-softmmu nios2-softmmu"
> > 
> > actual failure:
> > 
> > qemu/build $ QTEST_QEMU_BINARY=./qemu-system-or1k  ./tests/qtest/qos-test
> > 
> > failed to open module:
> > /build/qemu/qemu/build/qemu-bundle/usr/local/lib64/qemu/hw-display-virtio-vga.so:
> > undefined symbol: aml_return
> > qemu-system-or1k: ../util/error.c:59: error_setv: Assertion `*errp ==
> > NULL' failed.
> > Broken pipe
> > ../tests/qtest/libqtest.c:188: kill_qemu() detected QEMU death from
> > signal 6 (Aborted) (core dumped)
> > Aborted (core dumped)
> > 
> > CC: Bernhard Beschow <shentey@gmail.com>
> > Signed-off-by: Ani Sinha <ani@anisinha.ca>
> > ---
> >   hw/acpi/aml-build-stub.c | 10 ++++++++++
> >   1 file changed, 10 insertions(+)
> > 
> > changelog:
> > v2: cosmetic commit description format update.
> > 
> > diff --git a/hw/acpi/aml-build-stub.c b/hw/acpi/aml-build-stub.c
> > index 8d8ad1a314..89a8fec4af 100644
> > --- a/hw/acpi/aml-build-stub.c
> > +++ b/hw/acpi/aml-build-stub.c
> > @@ -26,6 +26,16 @@ void aml_append(Aml *parent_ctx, Aml *child)
> >   {
> >   }
> > +Aml *aml_return(Aml *val)
> > +{
> > +    return NULL;
> 
> Can't return NULL, otherwise aml_append() will crash.

This is what rest of functions do.

> We just want the symbol to be defined, so instead:
> 
>       g_assert_not_reached();
> 
> > +}

NULL derefs are actually somewhat easier to debug than asserts.

-- 
MST