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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8354AC3A59B for ; Fri, 30 Aug 2019 20:47:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 42C7E23439 for ; Fri, 30 Aug 2019 20:47:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728086AbfH3UrA (ORCPT ); Fri, 30 Aug 2019 16:47:00 -0400 Received: from smtprelay0233.hostedemail.com ([216.40.44.233]:46449 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728079AbfH3UrA (ORCPT ); Fri, 30 Aug 2019 16:47:00 -0400 Received: from filter.hostedemail.com (clb03-v110.bra.tucows.net [216.40.38.60]) by smtprelay05.hostedemail.com (Postfix) with ESMTP id 82D1E18024542; Fri, 30 Aug 2019 20:46:57 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: room74_212aeb625e22 X-Filterd-Recvd-Size: 10213 Received: from XPS-9350.home (unknown [47.151.137.30]) (Authenticated sender: joe@perches.com) by omf13.hostedemail.com (Postfix) with ESMTPA; Fri, 30 Aug 2019 20:46:54 +0000 (UTC) Message-ID: Subject: Re: [PATCH v2] kunit: fix failure to build without printk From: Joe Perches To: Brendan Higgins Cc: shuah , Sergey Senozhatsky , kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, frowand.list@gmail.com, sboyd@kernel.org, pmladek@suse.com, sergey.senozhatsky@gmail.com, rostedt@goodmis.org, Randy Dunlap , Stephen Rothwell Date: Fri, 30 Aug 2019 13:46:52 -0700 In-Reply-To: <20190830183821.GA30306@google.com> References: <20190828093143.163302-1-brendanhiggins@google.com> <20190828094929.GA14038@jagdpanzerIV> <8b2d63bf-56cd-e8f5-e8ee-2891c2c1be8f@kernel.org> <20190830183821.GA30306@google.com> Content-Type: text/plain; charset="ISO-8859-1" User-Agent: Evolution 3.32.1-2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Fri, 2019-08-30 at 11:38 -0700, Brendan Higgins wrote: > On Thu, Aug 29, 2019 at 09:44:58PM -0700, Joe Perches wrote: > > On Thu, 2019-08-29 at 11:01 -0600, shuah wrote: > > > On 8/28/19 3:49 AM, Sergey Senozhatsky wrote: > > > > On (08/28/19 02:31), Brendan Higgins wrote: > > > > [..] > > > > > Previously KUnit assumed that printk would always be present, which is > > > > > not a valid assumption to make. Fix that by removing call to > > > > > vprintk_emit, and calling printk directly. > > > > > > > > > > Reported-by: Randy Dunlap > > > > > Link: https://lore.kernel.org/linux-kselftest/0352fae9-564f-4a97-715a-fabe016259df@kernel.org/T/#t > > > > > Cc: Stephen Rothwell > > > > > Cc: Sergey Senozhatsky > > > > > Signed-off-by: Brendan Higgins > > > > > > > > [..] > > > > > > > > > -static void kunit_vprintk(const struct kunit *test, > > > > > - const char *level, > > > > > - struct va_format *vaf) > > > > > -{ > > > > > - kunit_printk_emit(level[1] - '0', "\t# %s: %pV", test->name, vaf); > > > > > -} > > > > > > > > This patch looks good to me. I like the removal of recursive > > > > vsprintf() (%pV). > > > > > > > > -ss > > > > > > > > > > Hi Sergey, > > > > > > What are the guidelines for using printk(). I recall some discussion > > > about not using printk(). I am seeing the following from checkpatch > > > script: > > > > > > > > > WARNING: Prefer [subsystem eg: netdev]_level([subsystem]dev, ... then > > > dev_level(dev, ... then pr_level(... to printk(KERN_LEVEL ... > > > #105: FILE: include/kunit/test.h:343: > > > + printk(KERN_LEVEL "\t# %s: " fmt, (test)->name, ##__VA_ARGS__) > > > > > > > > > Is there supposed to be pr_level() - I can find dev_level() > > > > > > cc'ing Joe Perches for his feedback on this message recommending > > > pr_level() which isn't in 5.3. > > > > I don't care for pr_level or KERN_LEVEL in a printk. > > I don't think I follow, how does your version fix this? > > > I think this is somewhat overly complicated. > > > > I think I'd write it like: > > --- > > include/kunit/test.h | 11 ++++----- > > kunit/test.c | 69 ++++++++++++++++------------------------------------ > > 2 files changed, 26 insertions(+), 54 deletions(-) > > > > diff --git a/include/kunit/test.h b/include/kunit/test.h > > index 8b7eb03d4971..aa4abf0a22a5 100644 > > --- a/include/kunit/test.h > > +++ b/include/kunit/test.h > > @@ -339,9 +339,8 @@ static inline void *kunit_kzalloc(struct kunit *test, size_t size, gfp_t gfp) > > > > void kunit_cleanup(struct kunit *test); > > > > -void __printf(3, 4) kunit_printk(const char *level, > > - const struct kunit *test, > > - const char *fmt, ...); > > +__printf(2, 3) > > +void kunit_printk(const struct kunit *test, const char *fmt, ...); > > > > /** > > * kunit_info() - Prints an INFO level message associated with @test. > > @@ -353,7 +352,7 @@ void __printf(3, 4) kunit_printk(const char *level, > > * Takes a variable number of format parameters just like printk(). > > */ > > #define kunit_info(test, fmt, ...) \ > > - kunit_printk(KERN_INFO, test, fmt, ##__VA_ARGS__) > > + kunit_printk(test, KERN_INFO fmt, ##__VA_ARGS__) > > > > /** > > * kunit_warn() - Prints a WARN level message associated with @test. > > @@ -364,7 +363,7 @@ void __printf(3, 4) kunit_printk(const char *level, > > * Prints a warning level message. > > */ > > #define kunit_warn(test, fmt, ...) \ > > - kunit_printk(KERN_WARNING, test, fmt, ##__VA_ARGS__) > > + kunit_printk(test, KERN_WARNING fmt, ##__VA_ARGS__) > > > > /** > > * kunit_err() - Prints an ERROR level message associated with @test. > > @@ -375,7 +374,7 @@ void __printf(3, 4) kunit_printk(const char *level, > > * Prints an error level message. > > */ > > #define kunit_err(test, fmt, ...) \ > > - kunit_printk(KERN_ERR, test, fmt, ##__VA_ARGS__) > > + kunit_printk(test, KERN_ERR fmt, ##__VA_ARGS__) > > > > /** > > * KUNIT_SUCCEED() - A no-op expectation. Only exists for code clarity. > > diff --git a/kunit/test.c b/kunit/test.c > > index b2ca9b94c353..ddb9bffb5a5d 100644 > > --- a/kunit/test.c > > +++ b/kunit/test.c > > @@ -16,40 +16,6 @@ static void kunit_set_failure(struct kunit *test) > > WRITE_ONCE(test->success, false); > > } > > > > -static int kunit_vprintk_emit(int level, const char *fmt, va_list args) > > -{ > > - return vprintk_emit(0, level, NULL, 0, fmt, args); > > -} > > - > > -static int kunit_printk_emit(int level, const char *fmt, ...) > > -{ > > - va_list args; > > - int ret; > > - > > - va_start(args, fmt); > > - ret = kunit_vprintk_emit(level, fmt, args); > > - va_end(args); > > - > > - return ret; > > -} > > - > > -static void kunit_vprintk(const struct kunit *test, > > - const char *level, > > - struct va_format *vaf) > > -{ > > - kunit_printk_emit(level[1] - '0', "\t# %s: %pV", test->name, vaf); > > -} > > - > > -static void kunit_print_tap_version(void) > > -{ > > - static bool kunit_has_printed_tap_version; > > - > > - if (!kunit_has_printed_tap_version) { > > - kunit_printk_emit(LOGLEVEL_INFO, "TAP version 14\n"); > > - kunit_has_printed_tap_version = true; > > - } > > -} > > - > > static size_t kunit_test_cases_len(struct kunit_case *test_cases) > > { > > struct kunit_case *test_case; > > @@ -63,11 +29,9 @@ static size_t kunit_test_cases_len(struct kunit_case *test_cases) > > > > static void kunit_print_subtest_start(struct kunit_suite *suite) > > { > > - kunit_print_tap_version(); > > - kunit_printk_emit(LOGLEVEL_INFO, "\t# Subtest: %s\n", suite->name); > > - kunit_printk_emit(LOGLEVEL_INFO, > > - "\t1..%zd\n", > > - kunit_test_cases_len(suite->test_cases)); > > + pr_info_once("TAP version 14\n"); > > + pr_info("\t# Subtest: %s\n", suite->name); > > + pr_info("\t1..%zd\n", kunit_test_cases_len(suite->test_cases)); > > } > > > > static void kunit_print_ok_not_ok(bool should_indent, > > @@ -87,9 +51,8 @@ static void kunit_print_ok_not_ok(bool should_indent, > > else > > ok_not_ok = "not ok"; > > > > - kunit_printk_emit(LOGLEVEL_INFO, > > - "%s%s %zd - %s\n", > > - indent, ok_not_ok, test_number, description); > > + pr_info("%s%s %zd - %s\n", > > + indent, ok_not_ok, test_number, description); > > } > > > > static bool kunit_suite_has_succeeded(struct kunit_suite *suite) > > @@ -133,11 +96,11 @@ static void kunit_print_string_stream(struct kunit *test, > > kunit_err(test, > > "Could not allocate buffer, dumping stream:\n"); > > list_for_each_entry(fragment, &stream->fragments, node) { > > - kunit_err(test, fragment->fragment); > > + kunit_err(test, "%s", fragment->fragment); > > } > > kunit_err(test, "\n"); > > } else { > > - kunit_err(test, buf); > > + kunit_err(test, "%s", buf); > > kunit_kfree(test, buf); > > } > > } > > @@ -505,19 +468,29 @@ void kunit_cleanup(struct kunit *test) > > } > > } > > > > -void kunit_printk(const char *level, > > - const struct kunit *test, > > - const char *fmt, ...) > > +void kunit_printk(const struct kunit *test, const char *fmt, ...) > > { > > + char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0"; > > struct va_format vaf; > > va_list args; > > + int kern_level; > > > > va_start(args, fmt); > > > > + while ((kern_level = printk_get_level(fmt)) != 0) { > > + size_t size = printk_skip_level(fmt) - fmt; > > + > > + if (kern_level >= '0' && kern_level <= '7') { > > + memcpy(lvl, fmt, size); > > + lvl[size] = '\0'; > > + } > > + fmt += size; > > + } > > + > > vaf.fmt = fmt; > > vaf.va = &args; > > > > - kunit_vprintk(test, level, &vaf); > > + printk("%s\t# %s %pV\n", lvl, test->name, &vaf); > > > > va_end(args); > > } > > How is this simpler? > > If we are okay with dynamically adding the KERN_ and %pV (and I > don't think that Sergey is), Sergey may well be in the minority overall as %pV is now very frequently used throughout the kernel. $ git grep "%pV" | wc -l 241 then wouldn't it be easier to pass in the > kernel level as a separate parameter and then strip off all printk > headers like this: Depends on whether or not you care for overall object size. Consolidated formats with the embedded KERN_ like suggested are smaller overall object size. This style is also already used in the kernel. > I don't know. I am clearly not an expert on this topic, but I don't see > the merit of the while loop you added above or dropping the level param. The while use is only to avoid misuses with consecutive KERN_ formats, which had happened in the past.