From: Maria Matejka <mq@ucw.cz>
Date: Wed, 11 Dec 2024 16:51:46 +0000 (+0100)
Subject: Fix alignment requirements to include atomic u64.
X-Git-Tag: v3.0.0~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=28b0adc15f82996a737fd832ef4a934dbbf29d93;p=thirdparty%2Fbird.git

Fix alignment requirements to include atomic u64.

Not having this led to bus errors on unaligned atomic u64 access
on architectures with 4B pointers.
---

diff --git a/lib/mempool.c b/lib/mempool.c
index 5940e5712..6de44b6bd 100644
--- a/lib/mempool.c
+++ b/lib/mempool.c
@@ -29,6 +29,7 @@ struct lp_chunk {
   struct lp_chunk *next;
   struct linpool *lp;
   uintptr_t data_align[0];
+  _Atomic u64 data_align_atomic[0];
   byte data[0];
 };
 
diff --git a/lib/resource.c b/lib/resource.c
index b89f772c1..17af79d75 100644
--- a/lib/resource.c
+++ b/lib/resource.c
@@ -373,7 +373,10 @@ tmp_flush(void)
 struct mblock {
   resource r;
   unsigned size;
-  uintptr_t data_align[0];
+  union {
+    uintptr_t bigint;
+    _Atomic u64 atom;
+  } _align[0];
   byte data[0];
 };
 
diff --git a/lib/slab.c b/lib/slab.c
index ab913f0cd..276ea8d09 100644
--- a/lib/slab.c
+++ b/lib/slab.c
@@ -171,6 +171,8 @@ struct sl_head {
 struct sl_alignment {			/* Magic structure for testing of alignment */
   byte data;
   int x[0];
+  _Atomic u64 y[0];
+  void *z[0];
 };
 
 #define TLIST_PREFIX sl_head