tests/acpi: don't pack a structure

[Qemu-devel] [PATCH] tests/acpi: don't pack a structure

Posted by Michael S. Tsirkin 7 years ago

There's no reason to pack structures where we don't care about size or
padding, this applies to AcpiStdTable in tests/acpi-utils.h.

OTOH bios-tables-test happens to be passing the address of a field in
this  struct to a function that expects a pointer to normally aligned
data which results in a SIGBUS on architectures like SPARC that have
strict alignment requirements.

Fixes: 9e8458c02 ("acpi unit-test: compare DSDT and SSDT tables against expected values")
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 tests/acpi-utils.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/acpi-utils.h b/tests/acpi-utils.h
index 9f9a2d5..348e4d7 100644
--- a/tests/acpi-utils.h
+++ b/tests/acpi-utils.h
@@ -26,7 +26,7 @@ typedef struct {
     gsize asl_len;
     gchar *asl_file;
     bool tmp_files_retain;   /* do not delete the temp asl/aml */
-} QEMU_PACKED AcpiSdtTable;
+} AcpiSdtTable;
 
 #define ACPI_READ_FIELD(field, addr)           \
     do {                                       \
-- 
MST

Re: [Qemu-devel] [PATCH] tests/acpi: don't pack a structure

Posted by Peter Maydell 7 years ago

On 30 March 2017 at 16:35, Michael S. Tsirkin <mst@redhat.com> wrote:
> There's no reason to pack structures where we don't care about size or
> padding, this applies to AcpiStdTable in tests/acpi-utils.h.
>
> OTOH bios-tables-test happens to be passing the address of a field in
> this  struct to a function that expects a pointer to normally aligned
> data which results in a SIGBUS on architectures like SPARC that have
> strict alignment requirements.
>
> Fixes: 9e8458c02 ("acpi unit-test: compare DSDT and SSDT tables against expected values")
> Reported-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  tests/acpi-utils.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tests/acpi-utils.h b/tests/acpi-utils.h
> index 9f9a2d5..348e4d7 100644
> --- a/tests/acpi-utils.h
> +++ b/tests/acpi-utils.h
> @@ -26,7 +26,7 @@ typedef struct {
>      gsize asl_len;
>      gchar *asl_file;
>      bool tmp_files_retain;   /* do not delete the temp asl/aml */
> -} QEMU_PACKED AcpiSdtTable;
> +} AcpiSdtTable;
>
>  #define ACPI_READ_FIELD(field, addr)           \
>      do {                                       \

Yes, this fixes the SPARC crashes.

Tested-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM