From patchwork Fri Apr 28 15:34:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alan Maguire X-Patchwork-Id: 13226589 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79C0AC7EE2A for ; Fri, 28 Apr 2023 15:35:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230336AbjD1PfK (ORCPT ); Fri, 28 Apr 2023 11:35:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346514AbjD1PfC (ORCPT ); Fri, 28 Apr 2023 11:35:02 -0400 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7FE881FFB; Fri, 28 Apr 2023 08:35:01 -0700 (PDT) Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 33SF3pBG013966; Fri, 28 Apr 2023 15:34:56 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2023-03-30; bh=YVCRBRkfFPkGR8hzIXJZIFGAb7lsTnmbW9p0HfFiVb4=; b=j/30y37wb+GSCqfEURAF8YuuxUyRjOt7dmgFfcFiqwGuv3O3H9pVp1S4fl16OR/gPfMa ix30NithNwsbW6WoknxKgHbUjJXBJfjZOR9VU/hFRFofSuS6SABeDC6RS5T3IUT0FvDe IS6LlIvToeOVney14FKeNEl1zke4na8KiIFJN6kJd9sCT4tKgGaeOg3gNEWjRTCL5HX9 rBA+nzVNSBNig6Q3DLm5j1xZvYs2XxMVc2rT/hSkUME+z+Wf5NkGCXeCYyxiM9g8+fPw oyVZR0U+NNvx8uILA1+dAX77rjGNX2WcdcVfkvsQC3dE2TEw+gh1C2wGZEL+AyMDhv6d Tw== Received: from phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta02.appoci.oracle.com [147.154.114.232]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3q460def5p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 28 Apr 2023 15:34:56 +0000 Received: from pps.filterd (phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 33SE6V1p028202; Fri, 28 Apr 2023 15:34:55 GMT Received: from pps.reinject (localhost [127.0.0.1]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3q461b4rnr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 28 Apr 2023 15:34:55 +0000 Received: from phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 33SFYqUC028134; Fri, 28 Apr 2023 15:34:54 GMT Received: from myrouter.uk.oracle.com (dhcp-10-175-188-60.vpn.oracle.com [10.175.188.60]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 3q461b4rm0-2; Fri, 28 Apr 2023 15:34:54 +0000 From: Alan Maguire To: rostedt@goodmis.org, mhiramat@kernel.org Cc: corbet@lwn.net, shuah@kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Alan Maguire Subject: [PATCH v2 tracing 1/6] tracing: support > 8 byte array filter predicates Date: Fri, 28 Apr 2023 16:34:44 +0100 Message-Id: <1682696089-27937-2-git-send-email-alan.maguire@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1682696089-27937-1-git-send-email-alan.maguire@oracle.com> References: <1682696089-27937-1-git-send-email-alan.maguire@oracle.com> X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-28_04,2023-04-27_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 mlxscore=0 phishscore=0 mlxlogscore=999 adultscore=0 suspectscore=0 malwarescore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304280125 X-Proofpoint-GUID: L4u-s7ivLQPx9SW7S1MLZl8zQFLl1SVw X-Proofpoint-ORIG-GUID: L4u-s7ivLQPx9SW7S1MLZl8zQFLl1SVw Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org For > 8 byte values, allow simple binary '==', '!=' predicates where the user passes in a hex ASCII representation of the desired value. The representation must match the field size exactly, and a simple memory comparison between predicate and actual value is carried out. For example: cd /sys/kernel/debug/tracing/events/tcp/tcp_receive_reset echo "saddr_v6 == 0x00000000000000000000000000000001" > filter Signed-off-by: Alan Maguire --- kernel/trace/trace_events_filter.c | 54 +++++++++++++++++++++++++++++- 1 file changed, 53 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 1dad64267878..64f1dfb72cb5 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -67,6 +67,7 @@ enum filter_pred_fn { FILTER_PRED_FN_FUNCTION, FILTER_PRED_FN_, FILTER_PRED_TEST_VISITED, + FILTER_PRED_FN_MEMCMP, }; struct filter_pred { @@ -622,8 +623,11 @@ predicate_parse(const char *str, int nr_parens, int nr_preds, kfree(op_stack); kfree(inverts); if (prog_stack) { - for (i = 0; prog_stack[i].pred; i++) + for (i = 0; prog_stack[i].pred; i++) { + if (prog_stack[i].pred->fn_num == FILTER_PRED_FN_MEMCMP) + kfree((u8 *)(uintptr_t)(prog_stack[i].pred->val)); kfree(prog_stack[i].pred); + } kfree(prog_stack); } return ERR_PTR(ret); @@ -890,6 +894,14 @@ static int filter_pred_function(struct filter_pred *pred, void *event) return pred->op == OP_EQ ? ret : !ret; } +static int filter_pred_memcmp(struct filter_pred *pred, void *event) +{ + u8 *mem = (u8 *)(event + pred->offset); + u8 *cmp = (u8 *)(uintptr_t)(pred->val); + + return (memcmp(mem, cmp, pred->field->size) == 0) ^ pred->not; +} + /* * regex_match_foo - Basic regex callbacks * @@ -1353,6 +1365,8 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event) return filter_pred_function(pred, event); case FILTER_PRED_TEST_VISITED: return test_pred_visited_fn(pred, event); + case FILTER_PRED_FN_MEMCMP: + return filter_pred_memcmp(pred, event); default: return 0; } @@ -1370,6 +1384,7 @@ static int parse_pred(const char *str, void *data, unsigned long size; unsigned long ip; char num_buf[24]; /* Big enough to hold an address */ + u8 *pred_val; char *field_name; char *name; bool function = false; @@ -1631,6 +1646,43 @@ static int parse_pred(const char *str, void *data, /* go past the last quote */ i++; + } else if (str[i] == '0' && tolower(str[i + 1]) == 'x' && + field->size > 8) { + /* For sizes > 8 bytes, we store hex bytes for comparison; + * only '==' and '!=' are supported. + * To keep things simple, the predicate value must specify + * a value that matches the field size exactly, with leading + * 0s if necessary. + */ + if (pred->op != OP_EQ && pred->op != OP_NE) { + parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i); + goto err_free; + } + + /* skip required 0x */ + s += 2; + i += 2; + + while (isalnum(str[i])) + i++; + + len = i - s; + if (len != (field->size * 2)) { + parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + s); + goto err_free; + } + + pred_val = kzalloc(field->size, GFP_KERNEL); + if (hex2bin(pred_val, str + s, field->size)) { + parse_error(pe, FILT_ERR_ILLEGAL_INTVAL, pos + s); + kfree(pred_val); + goto err_free; + } + pred->val = (u64)pred_val; + pred->fn_num = FILTER_PRED_FN_MEMCMP; + if (pred->op == OP_NE) + pred->not = 1; + } else if (isdigit(str[i]) || str[i] == '-') { /* Make sure the field is not a string */