On 18/04/2024 12:06 pm, Jan Beulich wrote:
> On 17.04.2024 09:14, Roger Pau Monné wrote:
>> On Tue, Apr 16, 2024 at 04:52:51PM +0100, Andrew Cooper wrote:
>>> --- a/xen/common/efi/pe.c
>>> +++ b/xen/common/efi/pe.c
>>> @@ -111,7 +111,8 @@ const void *__init pe_find_section(const void *image,
>>> const UINTN image_size,
>>> UINTN offset, i;
>>>
>>> if ( image_size < sizeof(*dos) ||
>>> - memcmp(dos->Magic, "MZ", 2) != 0 )
>>> + dos->Magic[0] != 'M' ||
>>> + dos->Magic[1] != 'Z' )
>> For this one you could likely use strncmp()?
> strncmp() against UINT8[2] wouldn't be liked by the compiler, I guess.
Indeed. And this MISRA rule is very much "you are mixing string and
non-string types. Don't do that."
This is a very rare patten, where we are looking for a binary marker
than just happens to also make sense when expressed as an ASCII string.
Although the MISRA complaint does raise a good point. The memcmp()
form would malfunction on any system with CHAR_BIT != 8, in a way that
the {u,}int8_t-at-a-time form wouldn't.
~Andrew
