diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2023-07-25 22:26:40 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-07-25 17:14:18 -0700 |
| commit | 63e2da3b7f7f63f881aa508825b0c4241e9910e1 (patch) | |
| tree | f9165139f432a4abf2a82afb9af74e9f41840fa6 /kernel | |
| parent | 13fd5e14afa57ba82189d5fd9ceb0435e5693bcc (diff) | |
bpf: work around -Wuninitialized warning
Splitting these out into separate helper functions means that we
actually pass an uninitialized variable into another function call
if dec_active() happens to not be inlined, and CONFIG_PREEMPT_RT
is disabled:
kernel/bpf/memalloc.c: In function 'add_obj_to_free_list':
kernel/bpf/memalloc.c:200:9: error: 'flags' is used uninitialized [-Werror=uninitialized]
200 | dec_active(c, flags);
Avoid this by passing the flags by reference, so they either get
initialized and dereferenced through a pointer, or the pointer never
gets accessed at all.
Fixes: 18e027b1c7c6d ("bpf: Factor out inc/dec of active flag into helpers.")
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230725202653.2905259-1-arnd@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/memalloc.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index 51d6389e5152..14d9b1a9a4ca 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -183,11 +183,11 @@ static void inc_active(struct bpf_mem_cache *c, unsigned long *flags) WARN_ON_ONCE(local_inc_return(&c->active) != 1); } -static void dec_active(struct bpf_mem_cache *c, unsigned long flags) +static void dec_active(struct bpf_mem_cache *c, unsigned long *flags) { local_dec(&c->active); if (IS_ENABLED(CONFIG_PREEMPT_RT)) - local_irq_restore(flags); + local_irq_restore(*flags); } static void add_obj_to_free_list(struct bpf_mem_cache *c, void *obj) @@ -197,7 +197,7 @@ static void add_obj_to_free_list(struct bpf_mem_cache *c, void *obj) inc_active(c, &flags); __llist_add(obj, &c->free_llist); c->free_cnt++; - dec_active(c, flags); + dec_active(c, &flags); } /* Mostly runs from irq_work except __init phase. */ @@ -344,7 +344,7 @@ static void free_bulk(struct bpf_mem_cache *c) cnt = --c->free_cnt; else cnt = 0; - dec_active(c, flags); + dec_active(c, &flags); if (llnode) enque_to_free(tgt, llnode); } while (cnt > (c->high_watermark + c->low_watermark) / 2); @@ -384,7 +384,7 @@ static void check_free_by_rcu(struct bpf_mem_cache *c) llist_for_each_safe(llnode, t, llist_del_all(&c->free_llist_extra_rcu)) if (__llist_add(llnode, &c->free_by_rcu)) c->free_by_rcu_tail = llnode; - dec_active(c, flags); + dec_active(c, &flags); } if (llist_empty(&c->free_by_rcu)) @@ -408,7 +408,7 @@ static void check_free_by_rcu(struct bpf_mem_cache *c) inc_active(c, &flags); WRITE_ONCE(c->waiting_for_gp.first, __llist_del_all(&c->free_by_rcu)); c->waiting_for_gp_tail = c->free_by_rcu_tail; - dec_active(c, flags); + dec_active(c, &flags); if (unlikely(READ_ONCE(c->draining))) { free_all(llist_del_all(&c->waiting_for_gp), !!c->percpu_size); |