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 51C3F3B059F; Tue, 13 Oct 2026 12:22:34 +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=1791894155; cv=none; b=ZF5Z086scI8sYSXIrfpDXUuoocWk1LOAeoMxU+HVFwjS8pse6Mxn44Puvt+/VjPlihIYqd5ykyEtZKCWIuKehKeY/oZqaYzFMes9smAR6gGrESDcFcbYu2ZJcbUstKl7ed7cHAIZBdCcAZOnK1Hvzh4qSXP1cqxAMbjAIpMQlS4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791894155; c=relaxed/simple; bh=FxJXaBZKSmwHGYoDecuAt0fPJn+TNAbNh/PkfKC+R80=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cRTgLJrWvhZ2vKwvPBMoi3jIvL3qwptFGkAjMQns68SgZaB6gcrGnfM/peJBBNgdS6oWJem7Md3UPbx2FRhJmAb6bkJzM3fUtkcu1eenLDuqi5J0UxmKA0tnwmvP4hp32Qetr2+qWD2XUamb7jxi2sVhDvm7albabNc3HwK53Xw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NxXIEAPe; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="NxXIEAPe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A586B1F000FF; Tue, 13 Oct 2026 12:22:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791894154; bh=Rucm0rBeQev4lHjERVDrhJi4QRorvKkgntO9LC3PmXI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NxXIEAPe4md3tUi9DRfSt6Lg95WdPUvsPhoRNlfFSM4g/CZvD6UN57fSexMtZ+3+k Sx9EaTYI9D8116CBdsEGtoB0JxOuYeGgw83TsR+VkB8LcbhJ8agqH01ouQNAfECEyh 07Jxdrw5671gsFlkm5sFoy+06WUFpemOcnrcSUK4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiri Olsa , Andrii Nakryiko , Sasha Levin Subject: [PATCH 6.18 438/621] bpf: Factor callchain_store function from __bpf_get_stack Date: Tue, 13 Oct 2026 13:37:13 +0200 Message-ID: <20261013112931.226825685@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112920.855194808@linuxfoundation.org> References: <20261013112920.855194808@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Olsa [ Upstream commit cbb99938e7935c9f62c891573a4b09690e5e22de ] The new callchain_store function stores trace entries buffer into user supplied buffer. It covers both just-ip and buildid data. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260803210149.296496-7-jolsa@kernel.org Stable-dep-of: f5d242825ca4 ("bpf: Clear buf on error in __bpf_get_task_stack") Signed-off-by: Sasha Levin --- kernel/bpf/stackmap.c | 39 +++++++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 14 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index c479f649596f9..933edcbb92f56 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -621,6 +621,29 @@ const struct bpf_func_proto bpf_get_stackid_proto_pe = { .arg3_type = ARG_ANYTHING, }; +static u32 callchain_store(struct perf_callchain_entry *trace, void *buf, + u32 elem_size, u64 flags) +{ + bool user_build_id = flags & BPF_F_USER_BUILD_ID; + u32 skip = flags & BPF_F_SKIP_FIELD_MASK; + u32 trace_nr, copy_len; + u64 *ips; + + trace_nr = trace->nr - skip; + copy_len = trace_nr * elem_size; + + ips = trace->ip + skip; + if (user_build_id) { + struct bpf_stack_build_id *id_offs = buf; + + for (u32 i = 0; i < trace_nr; i++) + id_offs[i].ip = ips[i]; + } else { + memcpy(buf, ips, copy_len); + } + return trace_nr; +} + 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) @@ -633,7 +656,6 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, struct perf_callchain_entry *trace; bool kernel = !user; int err = -EINVAL; - u64 *ips; if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | BPF_F_USER_BUILD_ID))) @@ -680,21 +702,10 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, goto err_fault; } - trace_nr = trace->nr - skip; + trace_nr = callchain_store(trace, buf, elem_size, flags); copy_len = trace_nr * elem_size; - ips = trace->ip + skip; - if (user_build_id) { - struct bpf_stack_build_id *id_offs = buf; - u32 i; - - for (i = 0; i < trace_nr; i++) - id_offs[i].ip = ips[i]; - } else { - memcpy(buf, ips, copy_len); - } - - /* trace/ips should not be dereferenced after this point */ + /* trace should not be dereferenced after this point */ if (may_fault) rcu_read_unlock(); preempt_enable(); -- 2.53.0