From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6829519D086; Thu, 25 Jul 2024 14:40:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721918406; cv=none; b=E+MaPFiYPCcGvu+wxO81scPcODKrZzCB3kjU9jpqERhn4Uoz2q1aSRczbqg4hJw26ZqJNLpRV0/n0mxiUtK4vjPqiGAYxiJXi/jHo7w/r4jl8dhvyyjV5qkbjxAFIZjKZJjC02YYECMVa+HQOOwfi761957UXCYyldj/bDezhSs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721918406; c=relaxed/simple; bh=JZzuceccPAKi7i7zjb9Qi2ngoBZt+ag/GATkL7So9MA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iFZ2Lzszkh+iUZOxcBPLvtiHJ31DtSRvS+XgIgZoei7BO1szgUIlJQLNfRqPhTP9B88HejGkVOdr5cDFBizZxSQGgqBw62Qs7CnwEfN1ypkYhNp7bCGxmrAp09Qucro0FtcdGFMA+YPdwgKyUSa+0CXbdQhTX9S3AG3V4Rrdjsw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rjPdnNtf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="rjPdnNtf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D04E2C116B1; Thu, 25 Jul 2024 14:40:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721918406; bh=JZzuceccPAKi7i7zjb9Qi2ngoBZt+ag/GATkL7So9MA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rjPdnNtfPhTJTijcYaAXfNWktyyFa+C7Rxli7z0a3kdBXxzR3JfpNAZzB1T4iR8ca aEu8pvc2l5Pi+qFfFRZl7fKrrdvtBvN9ioi7/BaupK82hJgc88WxFfyOBxszklB1v1 Lw+3Qk0UBShsO89dvbGGau9mHp0UtM+p4k9HX+S4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Masahiro Yamada , Randy Dunlap , Sasha Levin Subject: [PATCH 4.19 10/33] kconfig: remove wrong expr_trans_bool() Date: Thu, 25 Jul 2024 16:36:33 +0200 Message-ID: <20240725142728.911910274@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240725142728.511303502@linuxfoundation.org> References: <20240725142728.511303502@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masahiro Yamada [ Upstream commit 77a92660d8fe8d29503fae768d9f5eb529c88b36 ] expr_trans_bool() performs an incorrect transformation. [Test Code] config MODULES def_bool y modules config A def_bool y select C if B != n config B def_tristate m config C tristate [Result] CONFIG_MODULES=y CONFIG_A=y CONFIG_B=m CONFIG_C=m This output is incorrect because CONFIG_C=y is expected. Documentation/kbuild/kconfig-language.rst clearly explains the function of the '!=' operator: If the values of both symbols are equal, it returns 'n', otherwise 'y'. Therefore, the statement: select C if B != n should be equivalent to: select C if y Or, more simply: select C Hence, the symbol C should be selected by the value of A, which is 'y'. However, expr_trans_bool() wrongly transforms it to: select C if B Therefore, the symbol C is selected by (A && B), which is 'm'. The comment block of expr_trans_bool() correctly explains its intention: * bool FOO!=n => FOO ^^^^ If FOO is bool, FOO!=n can be simplified into FOO. This is correct. However, the actual code performs this transformation when FOO is tristate: if (e->left.sym->type == S_TRISTATE) { ^^^^^^^^^^ While it can be fixed to S_BOOLEAN, there is no point in doing so because expr_tranform() already transforms FOO!=n to FOO when FOO is bool. (see the "case E_UNEQUAL" part) expr_trans_bool() is wrong and unnecessary. Signed-off-by: Masahiro Yamada Acked-by: Randy Dunlap Signed-off-by: Sasha Levin --- scripts/kconfig/expr.c | 29 ----------------------------- scripts/kconfig/expr.h | 1 - scripts/kconfig/menu.c | 2 -- 3 files changed, 32 deletions(-) diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c index 7e38070ee523b..1c69de8cacf6d 100644 --- a/scripts/kconfig/expr.c +++ b/scripts/kconfig/expr.c @@ -395,35 +395,6 @@ static struct expr *expr_eliminate_yn(struct expr *e) return e; } -/* - * bool FOO!=n => FOO - */ -struct expr *expr_trans_bool(struct expr *e) -{ - if (!e) - return NULL; - switch (e->type) { - case E_AND: - case E_OR: - case E_NOT: - e->left.expr = expr_trans_bool(e->left.expr); - e->right.expr = expr_trans_bool(e->right.expr); - break; - case E_UNEQUAL: - // FOO!=n -> FOO - if (e->left.sym->type == S_TRISTATE) { - if (e->right.sym == &symbol_no) { - e->type = E_SYMBOL; - e->right.sym = NULL; - } - } - break; - default: - ; - } - return e; -} - /* * e1 || e2 -> ? */ diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h index 43a87f8ea738c..968219750244a 100644 --- a/scripts/kconfig/expr.h +++ b/scripts/kconfig/expr.h @@ -302,7 +302,6 @@ struct expr *expr_copy(const struct expr *org); void expr_free(struct expr *e); void expr_eliminate_eq(struct expr **ep1, struct expr **ep2); tristate expr_calc_value(struct expr *e); -struct expr *expr_trans_bool(struct expr *e); struct expr *expr_eliminate_dups(struct expr *e); struct expr *expr_transform(struct expr *e); int expr_contains_symbol(struct expr *dep, struct symbol *sym); diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c index 4cf15d449c05d..4d48ff3083bd8 100644 --- a/scripts/kconfig/menu.c +++ b/scripts/kconfig/menu.c @@ -390,8 +390,6 @@ void menu_finalize(struct menu *parent) dep = expr_transform(dep); dep = expr_alloc_and(expr_copy(basedep), dep); dep = expr_eliminate_dups(dep); - if (menu->sym && menu->sym->type != S_TRISTATE) - dep = expr_trans_bool(dep); prop->visible.expr = dep; /* -- 2.43.0