From: Willy Tarreau <w@1wt.eu>
Date: Wed, 22 Oct 2025 07:01:54 +0000 (+0200)
Subject: BUG/MAJOR: pools: fix default pool alignment
X-Git-Tag: v3.3-dev11~72
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f936feb3a97d9c576a5e38671a5678225ab7997e;p=thirdparty%2Fhaproxy.git

BUG/MAJOR: pools: fix default pool alignment

The doc in commit 977feb5617 ("DOC: api: update the pools API with the
alignment and typed declarations") says that alignment of zero means
the type's alignment. And this is followed by the DECLARE_TYPED_POOL()
macro. Yet this is not what is done in create_pool_from_reg() which
only raises the alignment to a void* if lower, while it should start
from the type's. The effect is haproxy refusing to start on some 32-bit
platforms since that commit, displaying an error such as:

   "BUG in the code: at src/mux_h2.c:454, requested creation of pool
    'h2s' aligned to 4 while type requires alignment of 8! Please
    report to developers. Aborting."

Let's just apply the default type's alignment.

Thanks to @tianon for reporting this in GH issue #3168. No backport is
needed since aligned pools are 3.3-only.
---

diff --git a/src/pool.c b/src/pool.c
index 9d247eb58..5108a81e6 100644
--- a/src/pool.c
+++ b/src/pool.c
@@ -344,6 +344,10 @@ struct pool_head *create_pool_from_reg(const char *name, struct pool_registratio
 	unsigned int best_diff;
 	int thr __maybe_unused;
 
+	/* alignment of zero means type alignment */
+	if (!alignment)
+		alignment = reg->type_align;
+
 	/* extend alignment if needed */
 	if (alignment < sizeof(void*))
 		alignment = sizeof(void*);