From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
linux-hardening@vger.kernel.org
Subject: [PATCH v2][next] cgroup: Avoid -Wstringop-overflow warnings
Date: Wed, 16 Aug 2023 14:50:16 -0600 [thread overview]
Message-ID: <ZN02iLcZYgxHFrEN@work> (raw)
Change the notation from pointer-to-array to pointer-to-pointer.
With this, we avoid the compiler complaining about trying
to access a region of size zero as an argument during function
calls.
Address the following -Wstringop-overflow warnings seen when
built with ARM architecture and aspeed_g4_defconfig configuration
(notice that under this configuration CGROUP_SUBSYS_COUNT == 0):
kernel/cgroup/cgroup.c:1208:16: warning: 'find_existing_css_set' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
kernel/cgroup/cgroup.c:1258:15: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
kernel/cgroup/cgroup.c:6089:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
kernel/cgroup/cgroup.c:6153:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
This results in no differences in binary output.
Link: https://github.com/KSPP/linux/issues/316
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
Changes in v2:
- Use pointer-to-pointer instead of pointer-to-array.
- Update changelog text.
v1:
- Link: https://lore.kernel.org/linux-hardening/ZIpm3pcs3iCP9UaR@work/
kernel/cgroup/cgroup.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index ccbbba06da5b..68e2d9812e3f 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -929,7 +929,7 @@ static void css_set_move_task(struct task_struct *task,
#define CSS_SET_HASH_BITS 7
static DEFINE_HASHTABLE(css_set_table, CSS_SET_HASH_BITS);
-static unsigned long css_set_hash(struct cgroup_subsys_state *css[])
+static unsigned long css_set_hash(struct cgroup_subsys_state **css)
{
unsigned long key = 0UL;
struct cgroup_subsys *ss;
@@ -1070,7 +1070,7 @@ static bool compare_css_sets(struct css_set *cset,
*/
static struct css_set *find_existing_css_set(struct css_set *old_cset,
struct cgroup *cgrp,
- struct cgroup_subsys_state *template[])
+ struct cgroup_subsys_state **template)
{
struct cgroup_root *root = cgrp->root;
struct cgroup_subsys *ss;
--
2.34.1
next reply other threads:[~2023-08-16 20:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-16 20:50 Gustavo A. R. Silva [this message]
2023-08-16 20:51 ` [PATCH v2][next] cgroup: Avoid -Wstringop-overflow warnings Tejun Heo
2023-08-16 20:57 ` Kees Cook
2023-08-16 21:01 ` Tejun Heo
2023-08-17 17:23 ` Gustavo A. R. Silva
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