From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3018518DF68; Mon, 28 Oct 2024 06:38:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730097488; cv=none; b=YFt7C4O6QCTlNSs3ekFRW2LewByxkvuUiG+Khv7Ai0N+NqPUyrsXXH6SWYxMxyqBk7LgiYseMm77aajcWazFtC9lAPCZtf7LEhAfEW1fQdn3hFI9cfjnqBPLYJE5LSNcD3R9g8mw85nUf1xUqDwLCEBcAhDqg2QkiHgWJh+ufB4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730097488; c=relaxed/simple; bh=rlLpASJxwf2vnndc4uZWy61h0eTWXMuUNT4c7nPNyN0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XYjZw9h0wRVmDitCEwpeUIqMP4at0d8VQAD3D3qsgu48Rul7XmI3dA5ymoQWYksrF1dmkCaQqpCe35TsyzlVxRBpjJjEeEFSfTTD2Xhe7k2rosYjr9Ebb0lnrV0DIGMXW0mawNzIMkf8oodqzPKB7e2QniWsEFQ7ZZRnQ8HOSPw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BB+Q9ySS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="BB+Q9ySS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75A33C4CEC3; Mon, 28 Oct 2024 06:38:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730097487; bh=rlLpASJxwf2vnndc4uZWy61h0eTWXMuUNT4c7nPNyN0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BB+Q9ySSuBqqMGirp5XLl1mUBx/ITCtgYtFAtoA/Si5611blDxYaurFCmgLKyXmuz d5ii5LqMGUYMpu8CGL9pWEBq6L9XDidE0++UO3LU23KhXgt27J1O+hZpMovlTjSKoF toATSNSl7NPwSWNc5uHO7iy/h3OfyM/ApH53r7rE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tyrone Wu , Jiri Olsa , Yafang Shao , Alexei Starovoitov , Sasha Levin Subject: [PATCH 6.6 015/208] bpf: fix unpopulated name_len field in perf_event link info Date: Mon, 28 Oct 2024 07:23:15 +0100 Message-ID: <20241028062307.033315165@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241028062306.649733554@linuxfoundation.org> References: <20241028062306.649733554@linuxfoundation.org> User-Agent: quilt/0.67 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tyrone Wu [ Upstream commit 4deecdd29cf29844c7bd164d72dc38d2e672f64e ] Previously when retrieving `bpf_link_info.perf_event` for kprobe/uprobe/tracepoint, the `name_len` field was not populated by the kernel, leaving it to reflect the value initially set by the user. This behavior was inconsistent with how other input/output string buffer fields function (e.g. `raw_tracepoint.tp_name_len`). This patch fills `name_len` with the actual size of the string name. Fixes: 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event") Signed-off-by: Tyrone Wu Acked-by: Jiri Olsa Acked-by: Yafang Shao Link: https://lore.kernel.org/r/20241008164312.46269-1-wudevelops@gmail.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- kernel/bpf/syscall.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 1d04d098f57db..b43302c80cac5 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3442,15 +3442,16 @@ static void bpf_perf_link_dealloc(struct bpf_link *link) } static int bpf_perf_link_fill_common(const struct perf_event *event, - char __user *uname, u32 ulen, + char __user *uname, u32 *ulenp, u64 *probe_offset, u64 *probe_addr, u32 *fd_type, unsigned long *missed) { const char *buf; - u32 prog_id; + u32 prog_id, ulen; size_t len; int err; + ulen = *ulenp; if (!ulen ^ !uname) return -EINVAL; @@ -3458,10 +3459,17 @@ static int bpf_perf_link_fill_common(const struct perf_event *event, probe_offset, probe_addr, missed); if (err) return err; + + if (buf) { + len = strlen(buf); + *ulenp = len + 1; + } else { + *ulenp = 1; + } if (!uname) return 0; + if (buf) { - len = strlen(buf); err = bpf_copy_to_user(uname, buf, ulen, len); if (err) return err; @@ -3486,7 +3494,7 @@ static int bpf_perf_link_fill_kprobe(const struct perf_event *event, uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); ulen = info->perf_event.kprobe.name_len; - err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr, + err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, &type, &missed); if (err) return err; @@ -3494,7 +3502,7 @@ static int bpf_perf_link_fill_kprobe(const struct perf_event *event, info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; else info->perf_event.type = BPF_PERF_EVENT_KPROBE; - + info->perf_event.kprobe.name_len = ulen; info->perf_event.kprobe.offset = offset; info->perf_event.kprobe.missed = missed; if (!kallsyms_show_value(current_cred())) @@ -3516,7 +3524,7 @@ static int bpf_perf_link_fill_uprobe(const struct perf_event *event, uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); ulen = info->perf_event.uprobe.name_len; - err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr, + err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, &type, NULL); if (err) return err; @@ -3525,6 +3533,7 @@ static int bpf_perf_link_fill_uprobe(const struct perf_event *event, info->perf_event.type = BPF_PERF_EVENT_URETPROBE; else info->perf_event.type = BPF_PERF_EVENT_UPROBE; + info->perf_event.uprobe.name_len = ulen; info->perf_event.uprobe.offset = offset; info->perf_event.uprobe.cookie = event->bpf_cookie; return 0; @@ -3550,12 +3559,18 @@ static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, { char __user *uname; u32 ulen; + int err; uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); ulen = info->perf_event.tracepoint.name_len; + err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); + if (err) + return err; + info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; + info->perf_event.tracepoint.name_len = ulen; info->perf_event.tracepoint.cookie = event->bpf_cookie; - return bpf_perf_link_fill_common(event, uname, ulen, NULL, NULL, NULL, NULL); + return 0; } static int bpf_perf_link_fill_perf_event(const struct perf_event *event, -- 2.43.0