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 D769F3AFCEE for ; Wed, 29 Jul 2026 08:39:20 +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=1785314361; cv=none; b=n7ZBTVK+NeiuF5c7sBtqCgd6xNaIJR5UtTe7VAqV6G3Chq+zrAPhzTr4WLkkB42K6nBS/s3WN1GhVS9qT2t21sQI2LZE8uGBpz9NbPCpR/L3Yk7vYXxGwu1eqAZWKXqKVSs/8LOLgAQljpZQIYFhXS8kwdB8aAGUb4GzxdZtvyk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785314361; c=relaxed/simple; bh=7gPggpOEzIIOWetD28ict+mXupJuQ8GNpxjfXqhYe0k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PZrtdmEJqif6/Bn65rudOfpbAdzhTSzj11wXhX0otKIyldCJ0vjAUlHUDoNhJSZY6IyZ/V/4CsTPPXfmw/hx5OvWmm/VYRxGjkUv29d3tDPvWtFhChW3QuJk5jUvXA7z/VfSIfc7fw/U7LWRqYbdnGKn8UOyRMHwGwc3fvBg/Og= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Hr0dTr0U; 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="Hr0dTr0U" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4E421F000E9; Wed, 29 Jul 2026 08:39:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785314360; bh=nFKnQSyfbszVGlApGE1MbY6DC03BTB8G3TcwLdX+rbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Hr0dTr0UkszXzqHj2kLCTR6rguDdtxc+X/qxw4cLMfINf5YcFTfC5+gpFqWgbDAJ9 VbrShP0CqA10OB6eqI/8iucohKOoPoFbTdifd5K4MGAwHeS78XLAoXTnqkl/JOGlUC 0K2YvJ3Q8AS2bFLNjd8fFtRqDR83lmpZyX/ejz5bKTGsEWgom2Y1cumn7gNsWul5vs pfmaQdWw3lJ4Y1R32mZIeK7NRs1G+m6UQiKTxFvjMtPAXsi6fw6orU6mKb7oO0F8nE dyH10S+car2v+tyFgdyNLaGxyZcOoP6PEfX/IO1pVAfitdodGojZhiYnDoMg6m70T+ iRIm0AqjW3LXQ== 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 , Arnaud Lecomte Subject: [PATCHv2 bpf-next 07/11] bpf: Factor callchain_finalize function from __bpf_get_stack Date: Wed, 29 Jul 2026 10:38:03 +0200 Message-ID: <20260729083807.1588544-8-jolsa@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260729083807.1588544-1-jolsa@kernel.org> References: <20260729083807.1588544-1-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 The new callchain_finalize function calls the build-id retrieval (if needed) and zeroes the buffer. Signed-off-by: Jiri Olsa --- kernel/bpf/stackmap.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 18b3db5c1fb9..05269f2a9e08 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -769,16 +769,29 @@ static u32 callchain_store(struct perf_callchain_entry *trace, void *buf, return trace_nr; } +static long callchain_finalize(void *buf, u32 size, u32 trace_nr, u32 elem_size, + bool user_build_id, bool user, bool may_fault) +{ + u32 copy_len = trace_nr * elem_size; + + if (user_build_id) + stack_map_get_build_id_offset(buf, trace_nr, user, may_fault); + + if (size > copy_len) + memset(buf + copy_len, 0, size - copy_len); + return copy_len; +} + static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, struct perf_callchain_entry *trace_in, void *buf, u32 size, u64 flags, bool may_fault) { - u32 trace_nr, copy_len, elem_size, max_depth; bool user_build_id = flags & BPF_F_USER_BUILD_ID; bool crosstask = task && task != current; u32 skip = flags & BPF_F_SKIP_FIELD_MASK; bool user = flags & BPF_F_USER_STACK; struct perf_callchain_entry *trace; + u32 trace_nr, elem_size, max_depth; bool kernel = !user; int err = -EINVAL; @@ -826,18 +839,12 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, } trace_nr = callchain_store(trace, buf, elem_size, flags); - copy_len = trace_nr * elem_size; /* trace should not be dereferenced after this point */ if (may_fault) rcu_read_unlock(); - if (user_build_id) - stack_map_get_build_id_offset(buf, trace_nr, user, may_fault); - - if (size > copy_len) - memset(buf + copy_len, 0, size - copy_len); - return copy_len; + return callchain_finalize(buf, size, trace_nr, elem_size, user_build_id, user, may_fault); err_fault: err = -EFAULT; -- 2.54.0