From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31727C433F5 for ; Mon, 8 Nov 2021 22:03:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B09361054 for ; Mon, 8 Nov 2021 22:03:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239515AbhKHWGh (ORCPT ); Mon, 8 Nov 2021 17:06:37 -0500 Received: from mail.kernel.org ([198.145.29.99]:56944 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231330AbhKHWGg (ORCPT ); Mon, 8 Nov 2021 17:06:36 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5C1E561054; Mon, 8 Nov 2021 22:03:51 +0000 (UTC) Date: Mon, 8 Nov 2021 17:03:49 -0500 From: Steven Rostedt To: Beau Belgrave Cc: mhiramat@kernel.org, linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 03/10] user_events: Add print_fmt generation support for basic types Message-ID: <20211108170349.66db0f58@gandalf.local.home> In-Reply-To: <20211104170433.2206-4-beaub@linux.microsoft.com> References: <20211104170433.2206-1-beaub@linux.microsoft.com> <20211104170433.2206-4-beaub@linux.microsoft.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Thu, 4 Nov 2021 10:04:26 -0700 Beau Belgrave wrote: > Addes print_fmt format generation for basic types that are supported for > user processes. Only supports sizes that are the same on 32 and 64 bit. > > Signed-off-by: Beau Belgrave > --- > kernel/trace/trace_events_user.c | 108 ++++++++++++++++++++++++++++++- > 1 file changed, 106 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c > index a68017ad7fdd..479a9ced3281 100644 > --- a/kernel/trace/trace_events_user.c > +++ b/kernel/trace/trace_events_user.c > @@ -329,6 +329,107 @@ static int user_event_parse_fields(struct user_event *user, char *args) > return ret; > } > > +static char *user_field_format(const char *type) Should be const char * > +{ > + if (strcmp(type, "s64") == 0) > + return "%lld"; > + if (strcmp(type, "u64") == 0) > + return "%llu"; > + if (strcmp(type, "s32") == 0) > + return "%d"; > + if (strcmp(type, "u32") == 0) > + return "%u"; > + if (strcmp(type, "int") == 0) > + return "%d"; > + if (strcmp(type, "unsigned int") == 0) > + return "%u"; > + if (strcmp(type, "s16") == 0) > + return "%d"; > + if (strcmp(type, "u16") == 0) > + return "%u"; > + if (strcmp(type, "short") == 0) > + return "%d"; > + if (strcmp(type, "unsigned short") == 0) > + return "%u"; > + if (strcmp(type, "s8") == 0) > + return "%d"; > + if (strcmp(type, "u8") == 0) > + return "%u"; > + if (strcmp(type, "char") == 0) > + return "%d"; > + if (strcmp(type, "unsigned char") == 0) > + return "%u"; > + if (strstr(type, "char[") != 0) > + return "%s"; > + > + /* Unknown, likely struct, allowed treat as 64-bit */ > + return "%llu"; > +} > + > +static bool user_field_is_dyn_string(const char *type) > +{ > + if (strstr(type, "__data_loc ") == type || > + strstr(type, "__rel_loc ") == type) { Use str_has_prefix(). -- Steve > + if (strstr(type, "char[") != 0) > + return true; > + } > + > + return false; > +} > + > +#define LEN_OR_ZERO (len ? len - pos : 0) > +static int user_event_set_print_fmt(struct user_event *user, char *buf, int len) > +{ > + struct ftrace_event_field *field, *next; > + struct list_head *head = &user->fields; > + int pos = 0, depth = 0; > + > + pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); > + > + list_for_each_entry_safe_reverse(field, next, head, link) { > + if (depth != 0) > + pos += snprintf(buf + pos, LEN_OR_ZERO, " "); > + > + pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s", > + field->name, user_field_format(field->type)); > + > + depth++; > + } > + > + pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); > + > + list_for_each_entry_safe_reverse(field, next, head, link) { > + if (user_field_is_dyn_string(field->type)) > + pos += snprintf(buf + pos, LEN_OR_ZERO, > + ", __get_str(%s)", field->name); > + else > + pos += snprintf(buf + pos, LEN_OR_ZERO, > + ", REC->%s", field->name); > + } > + > + return pos + 1; > +} > +#undef LEN_OR_ZERO > + > +static int user_event_create_print_fmt(struct user_event *user) > +{ > + char *print_fmt; > + int len; > + > + len = user_event_set_print_fmt(user, NULL, 0); > + > + print_fmt = kmalloc(len, GFP_KERNEL); > + > + if (!print_fmt) > + return -ENOMEM; > + > + user_event_set_print_fmt(user, print_fmt, len); > + > + user->call.print_fmt = print_fmt; > + > + return 0; > +} > + > static struct trace_event_fields user_event_fields_array[] = { > {} > }; > @@ -366,6 +467,7 @@ static int destroy_user_event(struct user_event *user) > clear_bit(user->index, page_bitmap); > hash_del(&user->node); > > + kfree(user->call.print_fmt); > kfree(EVENT_NAME(user)); > kfree(user); > > @@ -637,8 +739,10 @@ static int user_event_parse(char *name, char *args, char *flags, > if (ret) > goto put_user; > > - /* Minimal print format */ > - user->call.print_fmt = "\"\""; > + ret = user_event_create_print_fmt(user); > + > + if (ret) > + goto put_user; > > user->call.data = user; > user->call.class = &user->class;