From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18CEC330676; Sun, 16 Aug 2026 08:08:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.134.164.83 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786867727; cv=none; b=esPjiarknI2bkuZ9jwUEHmGCMQlrX+zP9XAcYUZx9thKr7oENA14buanULOt/MCnLiH5E4j1n1adYwRIiufZdHo1NEXx7ga4b3Lg7hsLpXeTvU4omJCmymTH0ffT6622MaA0QKwz7ofeAnywBXMGfFE17Hb+9nJo+Ll8sXwRw0w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786867727; c=relaxed/simple; bh=nOiX6qqnv+3vw0jkv/6+zWia5MuMlJohNRdS36FF07c=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=LY3cCS8FupbQ/aS35GNmhQoo2aBa1YDt2bH0Sqcw8qfBni5n/DUUWh8Sj3HER9xMB/tzbOgqDmh31iD4kUuUZUw3mqg5i1Eg6FhPHW7n3/v8871JjK+T/YAuqRr4EDcqd5ZbCiGILzZBfO/P6jYWpqRi44Qqxx8Fo5HV/skvyLw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=inria.fr; spf=pass smtp.mailfrom=inria.fr; dkim=pass (1024-bit key) header.d=inria.fr header.i=@inria.fr header.b=WsKwzinW; arc=none smtp.client-ip=192.134.164.83 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=inria.fr Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=inria.fr Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=inria.fr header.i=@inria.fr header.b="WsKwzinW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=inria.fr; s=dc; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=FY5aYwGF/nysJHvjVWkP/+mqsqcXSRqBExIQ99oxZk8=; b=WsKwzinWWqsEufajhI783h/1LB0CsI+DVNf6mAFTb3eNLHSbyaZFx9J5 y7P5Qz5FwJHozyiG3/hCe8FVLVpGAG+vsYR+BlEkT+Yx/f4TgkniwW/cn rBjWzTg/s+hAG1pffqr34JLjOITuKDR2sY2YbbhOmDAQYLXKeMmFj6DBk s=; X-CSE-ConnectionGUID: prJY2vJkRbus23zqETGmRw== X-CSE-MsgGUID: fRGXddh9Sd2kjEdNPR4aqw== Authentication-Results: mail2-relais-roc.national.inria.fr; dkim=none (message not signed) header.i=none; spf=SoftFail smtp.mailfrom=julia.lawall@inria.fr; dmarc=fail (p=none dis=none) d=inria.fr X-IronPort-AV: E=Sophos;i="6.25,226,1779141600"; d="scan'208";a="290275006" Received: from 88-188-149-159.subs.proxad.net (HELO hadrien.home) ([88.188.149.159]) by mail2-relais-roc.national.inria.fr with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Aug 2026 10:08:41 +0200 Date: Sun, 16 Aug 2026 10:08:40 +0200 (CEST) From: Julia Lawall To: Guru Das Srinagesh cc: Nicolas Palix , Michael Turquette , Stephen Boyd , linux-kernel@vger.kernel.org, cocci@inria.fr, Brian Masney , linux-clk@vger.kernel.org Subject: Re: [PATCH v3] coccinelle: Detect clk_register() anti-pattern In-Reply-To: Message-ID: <188bba40-bee-fb85-93c-fb59487dc861@inria.fr> References: <20260809-cocci-clk-register-v3-1-60d036e13370@gurudas.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Sun, 16 Aug 2026, Julia Lawall wrote: > > > On Sun, 9 Aug 2026, Guru Das Srinagesh wrote: > > > Enforce commit 12a0fd23e870 ("clk: Print an error when clk registration > > fails"): clk_register(), clk_hw_register(), and their devm_/of_ variants > > log their own error on failure, so driver-side error prints after these > > calls are redundant. > > Hello, > > This neglects a few cases found in current code: pr_crit, printk, and > DRM_DEV_ERROR > > A more extreme solution would be to not name the printing functions > explicitly, but have it be any function that is not returning a value > and that is taking a string as an argument. > > You can match a string with a metavariable like this: > > constant char [] c; > > and then the call site would be: > > *voidfn(...,c,...); > > another issue is that in one case, removing the error message leaves: > > ret = PTR_ERR(inno->phyclk); > return ret; > > This could be cleaned up to just return PTR_ERR(inno->phyclk) Note that there are lots of occurrences of ret = e; return ret; for some expression ret and e, and 99.99% of them are fine as is. But in this specific case of error handling code, perhaps it is not useful to introduce more of them. julia > > julia > > > > > > Two independent match families, one per return-value convention: > > pointer return checked via IS_ERR() (clk_register()/devm_clk_register()), > > and int return checked via a nonzero value (clk_hw_register()/ > > devm_clk_hw_register()/of_clk_hw_register()). Both families match > > regardless of whether the redundant message's "if" also has a trailing > > "else", via an "else S" clause with S otherwise unused. > > > > In "patch" mode, removing the redundant message also collapses the > > enclosing braces when only one statement remains, and deletes the whole > > "if" when the message was already the only (braceless) statement. > > > > Assisted-by: Claude:claude-sonnet-5 coccinelle > > Signed-off-by: Guru Das Srinagesh > > --- > > Add a Coccinelle semantic patch enforcing commit 12a0fd23e870 ("clk: > > Print an error when clk registration fails"): flags, and in "patch" > > mode removes, driver-side error prints that are now redundant after > > clk_register()/clk_hw_register() and their devm_/of_ variants. > > > > Two independent match families, one per return-value convention. > > > > Pointer return, IS_ERR()-checked (clk_register()/devm_clk_register()), > > e.g. drivers/clk/clk-xgene.c:152-157: > > > > clk = clk_register(dev, &apmclk->hw); > > if (IS_ERR(clk)) { > > - pr_err("%s: could not register clk %s\n", __func__, name); > > kfree(apmclk); > > return NULL; > > } > > > > Int return, nonzero-checked (clk_hw_register()/devm_clk_hw_register()/ > > of_clk_hw_register()), e.g. drivers/clk/meson/meson-clkc-utils.c:49-54: > > > > ret = devm_clk_hw_register(dev, hw); > > - if (ret) { > > - dev_err(dev, "registering %s clock failed\n", > > - hw->init->name); > > + if (ret) > > return ret; > > - } > > > > Already-braceless single-statement case: the whole "if" is deleted > > instead of just the message, e.g. drivers/clk/ux500/clk-sysctrl.c:171-175: > > > > clk_reg = devm_clk_register(clk->dev, &clk->hw); > > - if (IS_ERR(clk_reg)) > > - dev_err(dev, "clk_sysctrl: clk_register failed\n"); > > > > return clk_reg; > > > > Matches regardless of whether the "if" also has a trailing "else", via > > an "else S" clause with S otherwise unused, e.g. > > drivers/media/platform/microchip/microchip-isc-clk.c:269-275: > > > > isc_clk->clk = clk_register(isc->dev, &isc_clk->hw); > > - if (IS_ERR(isc_clk->clk)) { > > - dev_err(isc->dev, "%s: clock register fail\n", clk_name); > > + if (IS_ERR(isc_clk->clk)) > > return PTR_ERR(isc_clk->clk); > > - } else if (id == ISC_MCK) { > > + else if (id == ISC_MCK) { > > of_clk_add_provider(np, of_clk_src_simple_get, isc_clk->clk); > > } > > > > Testing: > > - Baseline: coccinelle 1.3.1, the Torvalds tree at v7.2-rc5. > > - "make coccicheck COCCI= MODE=report M=drivers/clk" produced 73 > > hits, unchanged after this revision, and verified to have zero false > > positives. > > - All four modes (report/context/patch/org) verified via "make > > coccicheck COCCI= MODE= [M=]" against the > > drivers/clk baseline and the new else-branch case above. > > - "make coccicheck COCCI= MODE=report" (whole tree, no M=) finds > > 94 hits; the 21 outside drivers/clk are not part of this series. > > --- > > Changes in v3 (Julia): > > - Match an "if" regardless of a trailing "else" (else S, S unused), > > across context/patch/report/org rules for both families. Found via > > this to be a real, previously-invisible case in > > drivers/media/platform/microchip/microchip-isc-clk.c. > > - Fix the org-mode script rules: cocci.print_main() takes (message, > > position), not just a position; the previous calls omitted the > > message entirely. > > - Drop the MAINTAINERS addition from v2 per Julia's comment that a > > specific maintainer isn't needed for this file. > > - Link to v2: https://patch.msgid.link/20260803-cocci-clk-register-v2-1-22e789f75f98@gurudas.dev > > > > Changes in v2 (Julia): > > - Use a literal function-name disjunction instead of a regex identifier, > > enabling spatch's file pre-filter optimization. > > - In "patch" mode, drop braces when only one statement remains, and > > delete the whole "if" when the message was the only (braceless) > > statement. > > - Drop two never-observed condition variants (IS_ERR(clk) == 1, ret != > > 0); keep the one with real precedent (ret < 0). > > - Link to v1: https://patch.msgid.link/20260802-cocci-clk-register-v1-1-df68afcb1eef@gurudas.dev > > --- > > scripts/coccinelle/api/clk_register.cocci | 165 ++++++++++++++++++++++++++++++ > > 1 file changed, 165 insertions(+) > > > > diff --git a/scripts/coccinelle/api/clk_register.cocci b/scripts/coccinelle/api/clk_register.cocci > > new file mode 100644 > > index 000000000000..150279827bf4 > > --- /dev/null > > +++ b/scripts/coccinelle/api/clk_register.cocci > > @@ -0,0 +1,165 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/// Remove error messages after clk registration failures, because > > +/// clk_register(), clk_hw_register(), and their variants already log > > +/// an error when they fail. See commit 12a0fd23e870 ("clk: Print an > > +/// error when clk registration fails"). > > +// > > +// Confidence: Medium > > +// Options: --include-headers > > + > > +virtual patch > > +virtual context > > +virtual org > > +virtual report > > + > > +@depends on context@ > > +expression clk; > > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > > +statement S; > > +@@ > > + > > +clk = \(clk_register\|devm_clk_register\)(...); > > +if ( IS_ERR(clk) ) > > +{ > > +... > > +*voidfn(...); > > +... > > +} > > +else S > > + > > +@depends on patch@ > > +expression clk; > > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > > +@@ > > + > > +clk = \(clk_register\|devm_clk_register\)(...); > > +-if ( IS_ERR(clk) ) > > +-voidfn(...); > > + > > +@depends on patch@ > > +expression clk; > > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > > +statement S, S_else; > > +@@ > > + > > +clk = \(clk_register\|devm_clk_register\)(...); > > +if ( IS_ERR(clk) ) > > +( > > +-{ > > +-voidfn(...); > > +S > > +-} > > +| > > +{ > > +... > > +-voidfn(...); > > +... > > +} > > +) > > +else S_else > > + > > +@r1 depends on org || report@ > > +position p1; > > +expression clk; > > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > > +statement S; > > +@@ > > + > > +clk = \(clk_register\|devm_clk_register\)(...); > > +if ( IS_ERR(clk) ) > > +{ > > +... > > +voidfn@p1(...); > > +... > > +} > > +else S > > + > > +@depends on context@ > > +expression ret; > > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > > +statement S; > > +@@ > > + > > +ret = \(clk_hw_register\|devm_clk_hw_register\|of_clk_hw_register\)(...); > > +if ( \( ret \| ret < 0 \) ) > > +{ > > +... > > +*voidfn(...); > > +... > > +} > > +else S > > + > > +@depends on patch@ > > +expression ret; > > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > > +@@ > > + > > +ret = \(clk_hw_register\|devm_clk_hw_register\|of_clk_hw_register\)(...); > > +-if ( \( ret \| ret < 0 \) ) > > +-voidfn(...); > > + > > +@depends on patch@ > > +expression ret; > > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > > +statement S, S_else; > > +@@ > > + > > +ret = \(clk_hw_register\|devm_clk_hw_register\|of_clk_hw_register\)(...); > > +if ( \( ret \| ret < 0 \) ) > > +( > > +-{ > > +-voidfn(...); > > +S > > +-} > > +| > > +{ > > +... > > +-voidfn(...); > > +... > > +} > > +) > > +else S_else > > + > > +@r2 depends on org || report@ > > +position p2; > > +expression ret; > > +identifier voidfn =~ "^(dev_err|dev_warn|pr_err|pr_warn)$"; > > +statement S; > > +@@ > > + > > +ret = \(clk_hw_register\|devm_clk_hw_register\|of_clk_hw_register\)(...); > > +if ( \( ret \| ret < 0 \) ) > > +{ > > +... > > +voidfn@p2(...); > > +... > > +} > > +else S > > + > > +@script:python depends on org@ > > +p1 << r1.p1; > > +@@ > > + > > +msg = "line %s is redundant because clk_register() already prints an error on failure" % (p1[0].line) > > +cocci.print_main(msg, p1) > > + > > +@script:python depends on report@ > > +p1 << r1.p1; > > +@@ > > + > > +msg = "line %s is redundant because clk_register() already prints an error on failure" % (p1[0].line) > > +coccilib.report.print_report(p1[0], msg) > > + > > +@script:python depends on org@ > > +p2 << r2.p2; > > +@@ > > + > > +msg = "line %s is redundant because clk_hw_register() already prints an error on failure" % (p2[0].line) > > +cocci.print_main(msg, p2) > > + > > +@script:python depends on report@ > > +p2 << r2.p2; > > +@@ > > + > > +msg = "line %s is redundant because clk_hw_register() already prints an error on failure" % (p2[0].line) > > +coccilib.report.print_report(p2[0], msg) > > > > --- > > base-commit: f5098b6bae761e346ebcd9da7f95622c04733cff > > change-id: 20260802-cocci-clk-register-951d94251af4 > > > > Best regards, > > -- > > Guru Das Srinagesh > > > > >