Changeset 1075ac6 in mainline for kernel/genarch/src/acpi/acpi.c

Timestamp:

2009-08-27T10:56:18Z (15 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

5418217

Parents:

6c3d54e

Message:

compare signatures byte-by-byte (avoid dereferencing type-punned pointers, which breaks strict-aliasing rules)

File:

• kernel/genarch/src/acpi/acpi.c (modified) (3 diffs)

kernel/genarch/src/acpi/acpi.c

@@ -46 +46 @@
 #define RSDP_REVISION_OFFS      15
 
+#define CMP_SIGNATURE(left, right) \
+        (((left)[0] == (right)[0]) && \
+        ((left)[1] == (right)[1]) && \
+        ((left)[2] == (right)[2]) && \
+        ((left)[3] == (right)[3]))
+
 struct acpi_rsdp *acpi_rsdp = NULL;
 struct acpi_rsdt *acpi_rsdt = NULL;
@@ -105 +111 @@
                         struct acpi_sdt_header *h = (struct acpi_sdt_header *) (unative_t) acpi_rsdt->entry[i];
                 
-                        map_sdt(h);     
-                        if (*((uint32_t *) &h->signature[0]) == *((uint32_t *) &signature_map[j].signature[0])) {
+                        map_sdt(h);
+                        if (CMP_SIGNATURE(h->signature, signature_map[j].signature)) {
                                 if (!acpi_sdt_check((uint8_t *) h))
                                         goto next;
@@ -127 +133 @@
 
                         map_sdt(h);
-                        if (*((uint32_t *) &h->signature[0]) == *((uint32_t *) &signature_map[j].signature[0])) {
+                        if (CMP_SIGNATURE(h->signature, signature_map[j].signature)) {
                                 if (!acpi_sdt_check((uint8_t *) h))
                                         goto next;