| Message ID | 20190220115934.15517-1-ard.biesheuvel@linaro.org |
|---|---|
| State | Accepted |
| Headers | show |
| Series | acpi/fadt: reject 5.0 tables with ARM specific attributes set | expand |
On 2019-02-20 12:59 p.m., Ard Biesheuvel wrote: > In ACPI 5.1, two reserved FADT fields were put to use, and renamed > to minor_version and arm_boot_flags, respectively. So compliant FADT > tables should either have a zero value in both fields, or have a > minor_version of at least 1 if the arm_boot_flags field is non-zero. > > Since ACPI 5.1 is the lowest version of the spec that actually reasons > about ARM systems at all, the Linux arm64 ACPI layer rejects 5.0 or > earlier implementations of the FADT. However, FADT implementations have > been observed in the wild that do define all the ARM specific pieces > that did not exist in ACPI 5.0, but still keep the minor_version field > at zero. So let's flag these implementations by only permitting a > non-zero value of arm_boot_flags if the minor_version is >=1. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > src/acpi/fadt/fadt.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/src/acpi/fadt/fadt.c b/src/acpi/fadt/fadt.c > index 14db51acda51..d7d6e3b862d1 100644 > --- a/src/acpi/fadt/fadt.c > +++ b/src/acpi/fadt/fadt.c > @@ -412,6 +412,13 @@ static void acpi_table_check_fadt_reserved(fwts_framework *fw) > fwts_failed(fw, LOG_LEVEL_MEDIUM, "FADTReservedZero", > "FADT second reserved field is not zero: 0x%02x", > fadt->reserved1); > + > + if (fadt->header.revision == 5 && > + fadt->minor_version == 0 && > + fadt->arm_boot_flags != 0) > + fwts_failed(fw, LOG_LEVEL_MEDIUM, "FADTReservedZero", > + "FADT 5.0 reserved field 'arm_boot_flags' is not zero: 0x%04x", > + fadt->arm_boot_flags); > } > > static void acpi_table_check_fadt_pm_profile(fwts_framework *fw) > Acked-by: Alex Hung <alex.hung@canonical.com>
On 20/02/2019 11:59, Ard Biesheuvel wrote: > In ACPI 5.1, two reserved FADT fields were put to use, and renamed > to minor_version and arm_boot_flags, respectively. So compliant FADT > tables should either have a zero value in both fields, or have a > minor_version of at least 1 if the arm_boot_flags field is non-zero. > > Since ACPI 5.1 is the lowest version of the spec that actually reasons > about ARM systems at all, the Linux arm64 ACPI layer rejects 5.0 or > earlier implementations of the FADT. However, FADT implementations have > been observed in the wild that do define all the ARM specific pieces > that did not exist in ACPI 5.0, but still keep the minor_version field > at zero. So let's flag these implementations by only permitting a > non-zero value of arm_boot_flags if the minor_version is >=1. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > src/acpi/fadt/fadt.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/src/acpi/fadt/fadt.c b/src/acpi/fadt/fadt.c > index 14db51acda51..d7d6e3b862d1 100644 > --- a/src/acpi/fadt/fadt.c > +++ b/src/acpi/fadt/fadt.c > @@ -412,6 +412,13 @@ static void acpi_table_check_fadt_reserved(fwts_framework *fw) > fwts_failed(fw, LOG_LEVEL_MEDIUM, "FADTReservedZero", > "FADT second reserved field is not zero: 0x%02x", > fadt->reserved1); > + > + if (fadt->header.revision == 5 && > + fadt->minor_version == 0 && > + fadt->arm_boot_flags != 0) > + fwts_failed(fw, LOG_LEVEL_MEDIUM, "FADTReservedZero", > + "FADT 5.0 reserved field 'arm_boot_flags' is not zero: 0x%04x", > + fadt->arm_boot_flags); > } > > static void acpi_table_check_fadt_pm_profile(fwts_framework *fw) > Thanks for this fix. Acked-by: Colin Ian King <colin.king@canonical.com>
diff --git a/src/acpi/fadt/fadt.c b/src/acpi/fadt/fadt.c index 14db51acda51..d7d6e3b862d1 100644 --- a/src/acpi/fadt/fadt.c +++ b/src/acpi/fadt/fadt.c @@ -412,6 +412,13 @@ static void acpi_table_check_fadt_reserved(fwts_framework *fw) fwts_failed(fw, LOG_LEVEL_MEDIUM, "FADTReservedZero", "FADT second reserved field is not zero: 0x%02x", fadt->reserved1); + + if (fadt->header.revision == 5 && + fadt->minor_version == 0 && + fadt->arm_boot_flags != 0) + fwts_failed(fw, LOG_LEVEL_MEDIUM, "FADTReservedZero", + "FADT 5.0 reserved field 'arm_boot_flags' is not zero: 0x%04x", + fadt->arm_boot_flags); } static void acpi_table_check_fadt_pm_profile(fwts_framework *fw)
In ACPI 5.1, two reserved FADT fields were put to use, and renamed to minor_version and arm_boot_flags, respectively. So compliant FADT tables should either have a zero value in both fields, or have a minor_version of at least 1 if the arm_boot_flags field is non-zero. Since ACPI 5.1 is the lowest version of the spec that actually reasons about ARM systems at all, the Linux arm64 ACPI layer rejects 5.0 or earlier implementations of the FADT. However, FADT implementations have been observed in the wild that do define all the ARM specific pieces that did not exist in ACPI 5.0, but still keep the minor_version field at zero. So let's flag these implementations by only permitting a non-zero value of arm_boot_flags if the minor_version is >=1. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- src/acpi/fadt/fadt.c | 7 +++++++ 1 file changed, 7 insertions(+)