From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-179.mta1.migadu.com (out-179.mta1.migadu.com [95.215.58.179]) (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 2273521FF3B for ; Fri, 5 Dec 2025 23:12:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764976339; cv=none; b=a3ba1ExSsjMFNWtijrtMHQrGBt8MzhzbQxGRoXk0240AeUIKO7GzSUK7wJDopvSS8tN7rvG4zkWAfL6le7EK4TsQ5fUy0doreP/gKbmxGCpEAhjC+pm/GYk89ZXS43sa2OsTRifYA5YqYENsyCZgPrCwsycvGuYUW9JUQlVQxCE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764976339; c=relaxed/simple; bh=jo3EcaFDbGYBlo3fqN/7e1jTrk1EwKAiT8S92LEdlSY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GnTRBySLSuj2SMAnHj/uAAfhx3nAIzl8BBaYFt8MbBsCozYV4UqyMTWCK5qqs28KIWzG8MRYJz65XvDUZykC5pOE+7eIJOuA02PXg56DBeHZ8Y0Q8EkAPzPvUG52ugfqkDYDp+UIT7L54Ocb0ZOQsOJgAdbgBe50lOoirDR8KA0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=b/YI44TB; arc=none smtp.client-ip=95.215.58.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="b/YI44TB" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1764976334; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=h/MYzAehkFQDpJ78ICQhSZnmM6tqkD8eXdkHrAUbgkQ=; b=b/YI44TBJcc1qJaLolT80ON1SvaUjaBRthAJmZ4EDH0aGrUV1Wm/UIiu1SnlxwdjGKF9hc JAFoaDi3PvlGyO/VL3+LjdQwtObbqce7xMmZO8cYSqRC7H31oBDAqeLRo/9SXSgbSBY7/0 Wo6/4I00FYrUNRII3QJ5/ruTQ1qeWBo= Date: Fri, 5 Dec 2025 15:12:01 -0800 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v3 2/6] resolve_btfids: Factor out load_btf() To: bot+bpf-ci@kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, akpm@linux-foundation.org, nathan@kernel.org, nsc@kernel.org, tj@kernel.org, void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, shuah@kernel.org, nick.desaulniers+lkml@gmail.com, morbo@google.com, justinstitt@google.com, alan.maguire@oracle.com, dolinux.peng@gmail.com Cc: bpf@vger.kernel.org, dwarves@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, martin.lau@kernel.org, clm@meta.com References: <20251205223046.4155870-3-ihor.solodrai@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Ihor Solodrai In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 12/5/25 2:57 PM, bot+bpf-ci@kernel.org wrote: >> diff --git a/tools/bpf/resolve_btfids/main.c b/tools/bpf/resolve_btfids/main.c >> index 164f0c941f04..b4caae1170dd 100644 >> --- a/tools/bpf/resolve_btfids/main.c >> +++ b/tools/bpf/resolve_btfids/main.c > > [ ... ] > >> @@ -529,16 +532,10 @@ static int symbols_collect(struct object *obj) >> return 0; >> } >> >> -static int symbols_resolve(struct object *obj) >> +static int load_btf(struct object *obj) >> { >> - int nr_typedefs = obj->nr_typedefs; >> - int nr_structs = obj->nr_structs; >> - int nr_unions = obj->nr_unions; >> - int nr_funcs = obj->nr_funcs; >> - struct btf *base_btf = NULL; >> - int err, type_id; >> - struct btf *btf; >> - __u32 nr_types; >> + struct btf *base_btf = NULL, *btf = NULL; >> + int err; >> >> if (obj->base_btf_path) { >> base_btf = btf__parse(obj->base_btf_path, NULL); >> err = libbpf_get_error(base_btf); >> if (err) { >> pr_err("FAILED: load base BTF from %s: %s\n", >> obj->base_btf_path, strerror(-err)); >> - return -1; >> + goto out_err; >> } >> } >> >> btf = btf__parse_split(obj->btf_path ?: obj->path, base_btf); >> err = libbpf_get_error(btf); >> if (err) { >> pr_err("FAILED: load BTF from %s: %s\n", >> obj->btf_path ?: obj->path, strerror(-err)); >> - goto out; >> + goto out_err; >> } >> >> + obj->base_btf = base_btf; >> + obj->btf = btf; >> + >> + return 0; >> + >> +out_err: >> + btf__free(base_btf); >> + btf__free(btf); >> + return err; > > Can btf__free() safely handle ERR_PTR values here? > > When btf__parse() fails on line 541, it returns ERR_PTR(-err), and > libbpf_get_error() extracts the error code, but base_btf still holds > the ERR_PTR value. The error path then calls btf__free(base_btf) > where base_btf is ERR_PTR rather than NULL or a valid pointer. > > The same issue occurs if btf__parse_split() fails on line 550, where > btf contains ERR_PTR when btf__free(btf) is called. > > In the old code at symbols_resolve(), if base_btf was ERR_PTR, the > function would return -1 immediately without calling btf__free(), > avoiding this issue. The new error handling with goto out_err changes > this behavior. That's a good observation. Interesting that AI noticed this only on third try, probably due to changes in prompts. btf__free() checks for error values [1], so this is not an issue. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/lib/bpf/btf.c?h=v6.18#n968 > >> +} >> + >> +static int symbols_resolve(struct object *obj) >> +{ >> + int nr_typedefs = obj->nr_typedefs; >> + int nr_structs = obj->nr_structs; >> + int nr_unions = obj->nr_unions; >> + int nr_funcs = obj->nr_funcs; >> + struct btf *btf = obj->btf; >> + int err, type_id; >> + __u32 nr_types; >> + >> err = -1; >> nr_types = btf__type_cnt(btf); > > [ ... ] > > > --- > AI reviewed your patch. Please fix the bug or email reply why it's not a bug. > See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md > > CI run summary: https://github.com/kernel-patches/bpf/actions/runs/19978081551