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 20A382BE7BE for ; Mon, 20 Jul 2026 08:54:36 +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=1784537678; cv=none; b=R8BHmZTeGHBBfIDlAgwsF6TUb19j8EUJpASO6vlnMFJ5mZ7wch9KfEkJfR7/bxWr4cIkLq7fER/WpQpOyXkGCRTikIdXMNhVpa/hWt/FsU8zEDqSMACmN2+IJJ5guuhVDagNeCzxJ8zkcZwa2TxQFgqZPIm9PWc2rgeWtSmuu94= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784537678; c=relaxed/simple; bh=XNlnREfHcYTheY4kcJ5CH8RUuNP7iSz9TBCabs/xRPs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hsuU8fh5sI+qzqi9bTg08R2ie/mBZr0WwXPjQV7BU45fa1y2KjBiUTNHFm171W7tbaOiRsxz4S+H2HDBrlPoFwLxokN/8CzESRrdeMiZbH78bmw/a1gCizYMBPmCoTVxX03rCHgj+ZK68L6rrtxbljojBrM4U4jkUjuT3VlLVr4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lCLYQwLw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lCLYQwLw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCD421F00A3A; Mon, 20 Jul 2026 08:54:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784537676; bh=luHXdK0ONN/kIETxNSUBhuj6n3kur92DmD1HIS4utoU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lCLYQwLw7VW5Bo3bY3Zb4AqC+h77cu2nxW/r8bblBDTyVe+O3mKR5f4GElS4p7EY/ 1hK4P8bq+Kq60wJxnK3r/QInX+dTbv5m3iqTOg4c6XhzbhjEqJ7GzIjL8TI6fbk/GR cAnYr6xNs0BYN5+tBQ/L8g70AgRMsXetyuCTYOXolIDt+oaWIPHV4iPT4MgylaukpW 4Mr3XJDnN7y9nVaMNF1/F280W353AxbzN8SM0dolgW3u3Oxf8wl+V+7oFH+DFY2Q1q GafQWZuNz9RYKe5aA+jcUZt5Mb1JtbE6NER+9SyH0WS6FHltclwKibBJMyE4wE10x9 aRAGIYlpT1V1Q== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: bpf@vger.kernel.org, Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , Quentin Monnet , Tao Chen , STAR Labs SG Subject: [PATCH bpf-next 4/9] bpf: Use stack id functions instead of __bpf_get_stackid Date: Mon, 20 Jul 2026 10:53:46 +0200 Message-ID: <20260720085351.655075-5-jolsa@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260720085351.655075-1-jolsa@kernel.org> References: <20260720085351.655075-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Replacing __bpf_get_stackid calls with sequence of following functions: stackid_fastpath stackid_new_bucket stackid_install This makes code more structured and allows us to easily disable preemption only in bpf_get_stackid in following changes. Signed-off-by: Jiri Olsa --- kernel/bpf/stackmap.c | 43 +++++++++++++++++++++++++++---------------- 1 file changed, 27 insertions(+), 16 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 48a2e28f0c68..83efd5892d90 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -585,22 +585,13 @@ stackid_new_bucket(struct stackid *stackid, struct bpf_map *map, return bucket; } -static long __bpf_get_stackid(struct stackid *stackid, struct bpf_map *map, - struct perf_callchain_entry *trace, u64 flags) +static long stackid_install(struct stackid *stackid, struct bpf_map *map, + struct stack_map_bucket *new_bucket, 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; + struct stack_map_bucket *old_bucket; u32 trace_len; - int err; - - err = stackid_fastpath(stackid, map, trace, flags); - if (err != -ENOENT) - return err; - - new_bucket = stackid_new_bucket(stackid, map, trace, flags); - if (!new_bucket) - return -ENOMEM; if (stack_map_use_build_id(map)) { struct bpf_stack_build_id *id_offs; @@ -630,10 +621,12 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, { u32 elem_size = stack_map_data_size(map); bool user = flags & BPF_F_USER_STACK; + struct stack_map_bucket *new_bucket; struct perf_callchain_entry *trace; struct stackid stackid; bool kernel = !user; u32 max_depth; + int err; if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID))) @@ -647,7 +640,15 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, /* couldn't fetch the stack trace */ return -EFAULT; - return __bpf_get_stackid(&stackid, map, trace, flags); + err = stackid_fastpath(&stackid, map, trace, flags); + if (err != -ENOENT) + return err; + + new_bucket = stackid_new_bucket(&stackid, map, trace, flags); + if (!new_bucket) + return -ENOMEM; + + return stackid_install(&stackid, map, new_bucket, flags); } const struct bpf_func_proto bpf_get_stackid_proto = { @@ -675,6 +676,7 @@ BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx, struct bpf_map *, map, u64, flags) { struct perf_event *event = ctx->event; + struct stack_map_bucket *new_bucket; struct perf_callchain_entry *trace; struct stackid stackid; bool kernel, user; @@ -702,7 +704,6 @@ BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx, if (kernel) { trace->nr = nr_kernel; - ret = __bpf_get_stackid(&stackid, map, trace, flags); } else { /* user */ u64 skip = flags & BPF_F_SKIP_FIELD_MASK; @@ -711,12 +712,22 @@ BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx, return -EFAULT; flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip; - ret = __bpf_get_stackid(&stackid, map, trace, flags); } + ret = stackid_fastpath(&stackid, map, trace, flags); + if (ret != -ENOENT) + goto error; + + new_bucket = stackid_new_bucket(&stackid, map, trace, flags); + if (new_bucket) { + trace->nr = nr; + return stackid_install(&stackid, map, new_bucket, flags); + } + ret = -ENOMEM; + +error: /* restore nr */ trace->nr = nr; - return ret; } -- 2.54.0