From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753551AbbJSM7W (ORCPT ); Mon, 19 Oct 2015 08:59:22 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:50793 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752035AbbJSM65 (ORCPT ); Mon, 19 Oct 2015 08:58:57 -0400 X-AuditID: cbfec7f4-f79c56d0000012ee-a4-5624e907367b From: Paul Osmialowski To: Jonathan Corbet , Arnd Bergmann , Andrew Morton , Petr Mladek , Greg Kroah-Hartman , Daniel Mack , Kay Sievers , Joe Perches , Tejun Heo , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-api@vger.kernel.org Cc: Marcin Niesluchowski , Karol Lewandowski , Paul Osmialowski , Bartlomiej Zolnierkiewicz , Shuah Khan Subject: [RFC v3 8/9] kmsg: add predefined _PID, _TID, _COMM keywords to kmsg* log dict Date: Mon, 19 Oct 2015 14:58:22 +0200 Message-id: <1445259503-18158-9-git-send-email-p.osmialowsk@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1445259503-18158-1-git-send-email-p.osmialowsk@samsung.com> References: <1445259503-18158-1-git-send-email-p.osmialowsk@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrBLMWRmVeSWpSXmKPExsVy+t/xa7rsL1XCDM6/1bWYs34Nm8XfScfY LTbOWM9q8eRAO6NF099XLBbNi9ezWcy+/5jFovHTXGaLyxvOsVls/t7BZrGwbQmLxeVdc9gs Dp39wWIx4c0BZouF/zczWUz98oHF4tfyo4wOgh6/f01i9Ni0qpPN48SM3ywe++euYfdY3DeZ 1WNL/112jy+rrjF79G1ZxehxZsERdo/Pm+Q8Pq739Ni+ezlLAE8Ul01Kak5mWWqRvl0CV8ba vY+ZC9rEKw5uPcTSwLhRqIuRk0NCwETiw4357BC2mMSFe+vZuhi5OIQEljJK3GldwwLhNDJJ TPkwkwmkik3AUOLm/8OMIAkRgbnMEs2/FrCCOMwCnxglfqxdDjZLWCBSYt3jTWAdLAKqEj8W H2TuYuTg4BXwkDh4MRxinZzEyWOTWUFsTgFPiXmfJrKDlAgBlfyf6TiBkXcBI8MqRtHU0uSC 4qT0XEO94sTc4tK8dL3k/NxNjJDw/7KDcfExq0OMAhyMSjy8N+pVwoRYE8uKK3MPMUpwMCuJ 8F6+ARTiTUmsrEotyo8vKs1JLT7EKM3BoiTOO3fX+xAhgfTEktTs1NSC1CKYLBMHp1QDo82l rYm1eotjExX5newPM9uqLdopuPj2jiOB0dlb936z2HO/4FjsvBfGlzUOHLnoGe44M+rnmljT qyc772anOLlJX5a3Z9/dsCci3DPnUcH0u5ZfQjiNdlmoFZ95m7HQZJtKg+iZf+eZ77CU+PdY V83YLuddvIbbeuY5iavBfE8PhvkejfrzSImlOCPRUIu5qDgRAE04cfl7AgAA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marcin Niesluchowski kmsg* devices write operation wrote no dict along with message Due to usage of kmsg devices in userspace dict has been added identifying pid, tid and comm of writing process. Signed-off-by: Marcin Niesluchowski Signed-off-by: Paul Osmialowski --- kernel/printk/kmsg.c | 40 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) diff --git a/kernel/printk/kmsg.c b/kernel/printk/kmsg.c index 0f56fc9..8c904fe 100644 --- a/kernel/printk/kmsg.c +++ b/kernel/printk/kmsg.c @@ -28,6 +28,17 @@ #define KMSG_MAX_MINOR_LEN 20 +#define MAX_PID_LEN 20 +#define MAX_TID_LEN 20 +/* + * Fromat below describes dict appended to message written from userspace: + * "_PID=\0_TID=\0_COMM=" + * KMSG_DICT_MAX_LEN definition represents maximal length of this dict. + */ +#define KMSG_DICT_MAX_LEN (5 + MAX_PID_LEN + 1 + \ + 5 + MAX_TID_LEN + 1 + \ + 6 + TASK_COMM_LEN) + /* /dev/kmsg - userspace message inject/listen interface */ struct devkmsg_user { u64 seq; @@ -37,7 +48,23 @@ struct devkmsg_user { char buf[CONSOLE_EXT_LOG_MAX]; }; -static int kmsg_sys_write(int minor, int level, const char *fmt, ...) +static size_t set_kmsg_dict(char *buf) +{ + size_t len; + + len = sprintf(buf, "_PID=%d", task_tgid_nr(current)) + 1; + len += sprintf(buf + len, "_TID=%d", task_pid_nr(current)) + 1; + memcpy(buf + len, "_COMM=", 6); + len += 6; + get_task_comm(buf + len, current); + while (buf[len] != '\0') + len++; + return len; +} + +static int kmsg_sys_write(int minor, int level, + const char *dict, size_t dictlen, + const char *fmt, ...) { va_list args; int ret = -ENXIO; @@ -52,7 +79,7 @@ static int kmsg_sys_write(int minor, int level, const char *fmt, ...) va_start(args, fmt); log_format_and_store(log_b, 1 /* LOG_USER */, level, - NULL, 0, fmt, args); + dict, dictlen, fmt, args); va_end(args); wake_up_interruptible(&log_b->wait); @@ -72,6 +99,8 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from) int level = default_message_loglevel; int facility = 1; /* LOG_USER */ size_t len = iov_iter_count(from); + char dict[KMSG_DICT_MAX_LEN]; + size_t dictlen; ssize_t ret = len; int minor = iminor(iocb->ki_filp->f_inode); @@ -111,10 +140,13 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from) } } + dictlen = set_kmsg_dict(dict); + if (minor == log_buf.minor) { - printk_emit(facility, level, NULL, 0, "%s", line); + printk_emit(facility, level, dict, dictlen, "%s", line); } else { - int error = kmsg_sys_write(minor, level, "%s", line); + int error = kmsg_sys_write(minor, level, dict, dictlen, + "%s", line); if (error) ret = error; -- 1.9.1