[exim-cvs] Fix unaligned access (more cleanly) in DNS regat…

Gitweb: https://git.exim.org/exim.git/commitdiff/3a2feed81419853e1288bd63b7887363a0c267b7

Commit:     3a2feed81419853e1288bd63b7887363a0c267b7
Parent:     927e32d4e26593314c5c287b3033ed550d648706
Author:     Jeremy Harris <jgh146exb@???>
AuthorDate: Sun Sep 8 14:41:48 2019 +0100
Committer:  Jeremy Harris <jgh146exb@???>
CommitDate: Sun Sep 8 14:41:48 2019 +0100

    Fix unaligned access (more cleanly) in DNS regative-caching
---
 src/src/dns.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/src/src/dns.c b/src/src/dns.c
index 04cb046..4465435 100644
--- a/src/src/dns.c
+++ b/src/src/dns.c
@@ -616,14 +616,10 @@ Arguments:
 Returns:     the return code
 */

-/*XXX the derivation of this value needs explaining */
+/* we need: 255 +1 + (max(typetext) == 5) +1 + max(chars_for_long-max) +1 */
#define DNS_FAILTAG_MAX 290
-#define alignment \
- (sizeof(void *) > sizeof(double) ? sizeof(void *) : sizeof(double))
-#define align(n) \
- (((((intptr_t)n) + (alignment-1)) / alignment) * alignment)
#define DNS_FAILNODE_SIZE \
- align(sizeof(tree_node) + DNS_FAILTAG_MAX + sizeof(expiring_data))
+ (sizeof(expiring_data) + sizeof(tree_node) + DNS_FAILTAG_MAX)

static int
dns_fail_return(const uschar * name, int type, time_t expiry, int rc)
@@ -637,10 +633,9 @@ if ((previous = tree_search(tree_dns_fails, node_name)))
e = previous->data.ptr;
else
{
- new = store_get_perm(DNS_FAILNODE_SIZE, is_tainted(name));
-
+ e = store_get_perm(DNS_FAILNODE_SIZE, is_tainted(name));
+ new = (void *)(e+1);
dns_fail_tag(new->name, name, type);
- e = (expiring_data *) align((char *)new + sizeof(tree_node) + DNS_FAILTAG_MAX);
new->data.ptr = e;
(void)tree_insertnode(&tree_dns_fails, new);
}