The checksums should be calculated using unsigned 32bit integers, as they are
intended to overflow and end at 0. Replace some other signed integers with
unsigned ones, to avoid mixed-sign comparisons.
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com>
---
CC: Jan Beulich <jbeul...@suse.com>
CC: Kevin Tian <kevin.t...@intel.com>
CC: Jun Nakajima <jun.nakaj...@intel.com>
v2:
* Include the extended checksum
* Swap more integers to being unsigned
---
xen/arch/x86/microcode_intel.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/xen/arch/x86/microcode_intel.c b/xen/arch/x86/microcode_intel.c
index 6949c25..93d9d0f 100644
--- a/xen/arch/x86/microcode_intel.c
+++ b/xen/arch/x86/microcode_intel.c
@@ -143,7 +143,8 @@ static int microcode_sanity_check(void *mc)
struct extended_sigtable *ext_header = NULL;
struct extended_signature *ext_sig;
unsigned long total_size, data_size, ext_table_size;
- int sum, orig_sum, ext_sigcount = 0, i;
+ unsigned int ext_sigcount = 0, i;
+ uint32_t sum, orig_sum;
total_size = get_totalsize(mc_header);
data_size = get_datasize(mc_header);
@@ -183,8 +184,8 @@ static int microcode_sanity_check(void *mc)
/* check extended table checksum */
if ( ext_table_size )
{
- int ext_table_sum = 0;
- int *ext_tablep = (int *)ext_header;
+ uint32_t ext_table_sum = 0;
+ uint32_t *ext_tablep = (uint32_t *)ext_header;
i = ext_table_size / DWSIZE;
while ( i-- )
@@ -201,7 +202,7 @@ static int microcode_sanity_check(void *mc)
orig_sum = 0;
i = (MC_HEADER_SIZE + data_size) / DWSIZE;
while ( i-- )
- orig_sum += ((int *)mc)[i];
+ orig_sum += ((uint32_t *)mc)[i];
if ( orig_sum )
{
printk(KERN_ERR "microcode: aborting, bad checksum\n");
--
2.1.4
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