| Message ID | 20210511205449.1676407-1-linux@roeck-us.net (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | faa5f5da809b690542e1108ba66886574ac57d2c |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net/sched: taprio: Drop unnecessary NULL check after container_of | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Guessed tree name to be net-next |
| netdev/subject_prefix | warning | Target tree name not specified in the subject |
| netdev/cc_maintainers | success | CCed 6 of 6 maintainers |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 2 this patch: 2 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 9 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 2 this patch: 2 |
| netdev/header_inline | success | Link |
Hello: This patch was applied to netdev/net-next.git (refs/heads/master): On Tue, 11 May 2021 13:54:49 -0700 you wrote: > The rcu_head pointer passed to taprio_free_sched_cb is never NULL. > That means that the result of container_of() operations on it is also > never NULL, even though rcu_head is the first element of the structure > embedding it. On top of that, it is misleading to perform a NULL check > on the result of container_of() because the position of the contained > element could change, which would make the check invalid. Remove the > unnecessary NULL check. > > [...] Here is the summary with links: - net/sched: taprio: Drop unnecessary NULL check after container_of https://git.kernel.org/netdev/net-next/c/faa5f5da809b You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 5c91df52b8c2..71e8a7a84841 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -114,9 +114,6 @@ static void taprio_free_sched_cb(struct rcu_head *head) struct sched_gate_list *sched = container_of(head, struct sched_gate_list, rcu); struct sched_entry *entry, *n; - if (!sched) - return; - list_for_each_entry_safe(entry, n, &sched->entries, list) { list_del(&entry->list); kfree(entry);
The rcu_head pointer passed to taprio_free_sched_cb is never NULL. That means that the result of container_of() operations on it is also never NULL, even though rcu_head is the first element of the structure embedding it. On top of that, it is misleading to perform a NULL check on the result of container_of() because the position of the contained element could change, which would make the check invalid. Remove the unnecessary NULL check. This change was made automatically with the following Coccinelle script. @@ type t; identifier v; statement s; @@ <+... ( t v = container_of(...); | v = container_of(...); ) ... when != v - if (\( !v \| v == NULL \) ) s ...+> Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- net/sched/sch_taprio.c | 3 --- 1 file changed, 3 deletions(-)