[PATCH] xen/efi: Rewrite DOS/PE magic checking without memcmp()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Misra Rule 21.16 doesn't like the use of memcmp() between a string literal and
a UINT8 array.  Rewrite using plain compares.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: consulting@xxxxxxxxxxx <consulting@xxxxxxxxxxx>
CC: Roberto Bagnara <roberto.bagnara@xxxxxxxxxxx>
CC: Federico Serafini <federico.serafini@xxxxxxxxxxx>
CC: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
---
 xen/common/efi/pe.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/xen/common/efi/pe.c b/xen/common/efi/pe.c
index a84992df9afe..ef8a2543e0a1 100644
--- 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' )
         return NULL;
 
     offset = dos->ExeHeader;
@@ -119,7 +120,10 @@ const void *__init pe_find_section(const void *image, 
const UINTN image_size,
 
     offset += sizeof(*pe);
     if ( image_size < offset ||
-         memcmp(pe->Magic, "PE\0\0", 4) != 0 )
+         pe->Magic[0] != 'P' ||
+         pe->Magic[1] != 'E' ||
+         pe->Magic[2] != '\0' ||
+         pe->Magic[3] != '\0' )
         return NULL;
 
     if ( pe->FileHeader.Machine != PE_HEADER_MACHINE )

base-commit: c0f890cd9d5fd2c17a1e3110cb26f98c90ce8429
-- 
2.30.2