From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751892AbbJLJbs (ORCPT ); Mon, 12 Oct 2015 05:31:48 -0400 Received: from mailout3.w1.samsung.com ([210.118.77.13]:13816 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752056AbbJLJ3x (ORCPT ); Mon, 12 Oct 2015 05:29:53 -0400 X-AuditID: cbfec7f4-f79c56d0000012ee-a7-561b7d8da2d3 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 v2 6/9] kmsg: add predefined _PID, _TID, _COMM keywords to kmsg* log dict Date: Mon, 12 Oct 2015 11:29:14 +0200 Message-id: <1444642157-32618-7-git-send-email-p.osmialowsk@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1444642157-32618-1-git-send-email-p.osmialowsk@samsung.com> References: <1444642157-32618-1-git-send-email-p.osmialowsk@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrBLMWRmVeSWpSXmKPExsVy+t/xy7q9tdJhBvO2iFjMWb+GzeLvpGPs FhtnrGe1eHKgndGi6e8rFovmxevZLGbff8xi0fhpLrPF5Q3n2Cw2f+9gs1jYtoTF4vKuOWwW h87+YLGY8OYAs8XC/5uZLKZ++cBi8Wv5UUYHQY/fvyYxemxa1cnmcWLGbxaP/XPXsHss7pvM 6rGl/y67x5dV15g9+rasYvQ4s+AIu8fnTXIeH9d7emzfvZwlgCeKyyYlNSezLLVI3y6BK+Pr 6YiC3aIVxyfENzBOFOxi5OSQEDCRWLbmKCOELSZx4d56ti5GLg4hgaWMEi9W/WOEcBqZJA69 v8sEUsUmYChx8/9hsISIwFxmieZfC1hBHGaBT4wSP9YuZwepEhaIlHjZeo4NxGYRUJXY2rES zOYV8JBY/O8UC8Q+OYmTxyazgticAp4Sf8+uB9sgBFTzeGsL0wRG3gWMDKsYRVNLkwuKk9Jz DfWKE3OLS/PS9ZLzczcxQsL/yw7GxcesDjEKcDAq8fBybJEKE2JNLCuuzD3EKMHBrCTCuzdI OkyINyWxsiq1KD++qDQntfgQozQHi5I479xd70OEBNITS1KzU1MLUotgskwcnFINjEvCF2qz PWCRLFTo8kn903tTsKQlvCb1ybH0VZJH+6dfmiVsevlaYcD2zikGUXUs7rZ3qg9tXLLol7zK qpNCAlq1JnOeXvNWmJbhG8hhMKV9E2M7p+UR16trdJ5Jzb6ycoGc/lJmfi3eoBl3N7axymVP nfVl7xeDhasl/i5PSJnwwf6YzTwbaSWW4oxEQy3mouJEAE8yyGx7AgAA 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 --- kernel/printk/printk.c | 40 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index aac7ce8..c13ba89 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -877,7 +877,34 @@ void log_buf_release(struct kref *ref) kfree(log_b); } -static int kmsg_sys_write(int minor, int level, const char *fmt, ...) +#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) + +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; @@ -892,7 +919,7 @@ 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); @@ -912,6 +939,8 @@ 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); @@ -951,10 +980,13 @@ 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