From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D1585472762 for ; Tue, 8 Sep 2026 13:21:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788873714; cv=none; b=pw7Q/micDnyWwiUpZpbn2rJxk98/7LBSmWyWCWsOQS2qbgqUvSm60dAXH8lxSy/nP8Wf2nHzFgAtNq9v7BNKC0Ub7+Wl/LamvZplRhM0BnCugql3mNzOpCormwD2gQBldW3WvNbjOKWHPC5buQlt3wPkvoxld9/ZOy3motUuZYA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788873714; c=relaxed/simple; bh=6IGpnx2+NstMtHXB3GJEfT8X9NSBVP1DtB9ME9xMcwc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TeEEZgX2eELUr9SjQK38cFmQ/1AwxWknedcXfAP8Vp15YvsYBU1PMtP56a7EKuQxVGAmtIjjGF+WZjQ6mwlQtKmqHBuW0+0kd3NI61Qsf5AdC9BtrTWE9sdhOOwMpu+PkUxzu5sm6jEpEqhpzQiGGD0GjwlZ79C04nHdm3lklM0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06C341F00A3E; Tue, 8 Sep 2026 13:21:51 +0000 (UTC) From: Sasha Levin To: stable@vger.kernel.org Cc: Jiri Olsa , Andrii Nakryiko , Sasha Levin Subject: [PATCH 6.12.y 3/5] bpf: Factor stackid_new_bucket from __bpf_get_stackid Date: Tue, 8 Sep 2026 09:21:46 -0400 Message-ID: <20260908132148.2288072-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260908132148.2288072-1-sashal@kernel.org> References: <2026090349-donor-crunching-700c@gregkh> <20260908132148.2288072-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Jiri Olsa [ Upstream commit bb4e6f4e1b68fe60c04ca04c564c6624e837dbf4 ] The new stackid_new_bucket allocates the new bucket and initializes it with the trace data. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260803210149.296496-4-jolsa@kernel.org Stable-dep-of: 15f1bd857466 ("bpf: Disable preemption in bpf_get_stackid") Signed-off-by: Sasha Levin --- kernel/bpf/stackmap.c | 48 +++++++++++++++++++++++++++---------------- 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 605543688c81b..b9ed6256d6307 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -301,31 +301,52 @@ static int stackid_fastpath(struct stackid *stackid, struct bpf_map *map, return -ENOENT; } +static struct stack_map_bucket * +stackid_new_bucket(struct stackid *stackid, struct bpf_map *map) +{ + struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); + struct bpf_stack_build_id *id_offs; + struct stack_map_bucket *bucket; + u32 i; + + bucket = (struct stack_map_bucket *) pcpu_freelist_pop(&smap->freelist); + if (unlikely(!bucket)) + return NULL; + + if (stack_map_use_build_id(map)) { + id_offs = (struct bpf_stack_build_id *)bucket->data; + for (i = 0; i < stackid->nr; i++) + id_offs[i].ip = stackid->ips[i]; + } else { + memcpy(bucket->data, stackid->ips, stackid->len); + } + + bucket->hash = stackid->hash; + bucket->nr = stackid->nr; + return bucket; +} + static long __bpf_get_stackid(struct stackid *stackid, struct bpf_map *map, struct perf_callchain_entry *trace, u64 flags) { struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); struct stack_map_bucket *new_bucket, *old_bucket; bool user = flags & BPF_F_USER_STACK; - u32 trace_len, i; + u32 trace_len; int err; err = stackid_fastpath(stackid, map, trace, flags); if (err != -ENOENT) return err; + new_bucket = stackid_new_bucket(stackid, map); + if (!new_bucket) + return -ENOMEM; + if (stack_map_use_build_id(map)) { struct bpf_stack_build_id *id_offs; - /* for build_id+offset, pop a bucket before slow cmp */ - new_bucket = (struct stack_map_bucket *) - pcpu_freelist_pop(&smap->freelist); - if (unlikely(!new_bucket)) - return -ENOMEM; - new_bucket->nr = stackid->nr; id_offs = (struct bpf_stack_build_id *)new_bucket->data; - for (i = 0; i < stackid->nr; i++) - id_offs[i].ip = stackid->ips[i]; stack_map_get_build_id_offset(id_offs, stackid->nr, user, false /* !may_fault */); trace_len = stackid->nr * sizeof(struct bpf_stack_build_id); if (stackid->hash_matches && stackid->bucket->nr == stackid->nr && @@ -337,17 +358,8 @@ static long __bpf_get_stackid(struct stackid *stackid, struct bpf_map *map, pcpu_freelist_push(&smap->freelist, &new_bucket->fnode); return -EEXIST; } - } else { - new_bucket = (struct stack_map_bucket *) - pcpu_freelist_pop(&smap->freelist); - if (unlikely(!new_bucket)) - return -ENOMEM; - memcpy(new_bucket->data, stackid->ips, stackid->len); } - new_bucket->hash = stackid->hash; - new_bucket->nr = stackid->nr; - old_bucket = xchg(&smap->buckets[stackid->id], new_bucket); if (old_bucket) pcpu_freelist_push(&smap->freelist, &old_bucket->fnode); -- 2.53.0