From: Luca Boccassi <luca.boccassi@gmail.com>
Date: Fri, 25 Jul 2025 14:16:22 +0000 (+0100)
Subject: cgroup-util: enforce alignment of f_handle
X-Git-Tag: v258-rc2~84
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a3eb0e99d32aadb7126fc898ede6dd748bbbc050;p=thirdparty%2Fsystemd.git

cgroup-util: enforce alignment of f_handle

The change in 4d2e61211df7244fae6aaeb8cae0916b4a0e78bd
broke armv7 where uintptr_t is 4 bytes:

/* test_id */
Assertion '((uintptr_t) _p) % alignof(uint64_t) == 0' failed at src/basic/cgroup-util.c:108, function cg_get_cgroupid_at(). Aborting.

(gdb) p (uintptr_t)fh.file_handle.f_handle % _Alignof(uint64_t)
$9 = 4

Enforce that the structure is aligned as expected

Follow-up for 4d2e61211df7244fae6aaeb8cae0916b4a0e78bd
---

diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index 0184cbffbec..0dc13bc958c 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -38,7 +38,7 @@
 typedef union {
         struct file_handle file_handle;
         uint8_t space[offsetof(struct file_handle, f_handle) + sizeof(uint64_t)];
-} cg_file_handle;
+} _alignas_(uint64_t) cg_file_handle;
 
 #define CG_FILE_HANDLE_INIT                                     \
         (cg_file_handle) {                                      \