On 4/6/23 01:48, Tom Rini wrote:
When building with clang we see this warning: field guid within 'struct efi_hii_keyboard_layout' is less aligned than 'efi_guid_t' and is usually due to 'struct efi_hii_keyboard_layout' being packed, which can lead to unaligned accesses [-Wunaligned-access]
Which is correct and true as EFI payloads are by specification allowed to do unaligned access. And so to silence the warning here and only here, we make use of #pragma to push/pop turning off the warning.
Signed-off-by: Tom Rini trini@konsulko.com
Cc: Heinrich Schuchardt xypron.glpk@gmx.de Cc: Ilias Apalodimas ilias.apalodimas@linaro.org
include/efi_api.h | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/include/efi_api.h b/include/efi_api.h index dc6e5ce236c9..f3bcbf593bea 100644 --- a/include/efi_api.h +++ b/include/efi_api.h @@ -1168,9 +1168,21 @@ struct efi_key_descriptor { u16 affected_attribute; } __packed;
+/* The warniing:
- field guid within 'struct efi_hii_keyboard_layout' is less aligned than 'efi_guid_t' and is usually due to 'struct efi_hii_keyboard_layout' being packed, which can lead to unaligned accesses [-Wunaligned-access]
- is intentional due to EFI requiring unaligned access to be supported.
- */ struct efi_hii_keyboard_layout { u16 layout_length;
+#ifdef CONFIG_CC_IS_CLANG +#pragma clang diagnostic push +#pragma clang diagnostic ignored "-Wunaligned-access" +#endif efi_guid_t guid; +#ifdef CONFIG_CC_IS_CLANG +#pragma clang diagnostic pop +#endif
I don't think that the clang warning should be suppressed. We should replace efi_guid_t by u8[16] instead. This will force us to take the missing alignment into account when accessing the component in future.
- efi_guid_t guid; + u8 guid[16];
Best regards
Heinrich
- u32 layout_descriptor_string_offset; u8 descriptor_count; struct efi_key_descriptor descriptors[];