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 A9EF313DDB8; Thu, 25 Jul 2024 14:51:52 +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=1721919112; cv=none; b=XIwAWKUVa3fiNBA4lj80GEUqQ5wwjGFrOq6YeUOdIkRFTtDls+jjgoJqtork5PYSssTupExPIqCRaFPRp6W2+R8y6zcJt8urwgTclp5IMtusPbvA7T1ESTBTi2wcdPR4qrpfI3PcjH2B2O2WZNMl+1SZOtZUUxCrfwUO1w6HB/E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721919112; c=relaxed/simple; bh=+P6flF0kanCxASEJFyAlazCsWInv1Xrq2TLRPhUxy74=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TDmgc7q2XpDbPk5QdvooNHUJqtFQDa3Of201Hm8LPW0Q54O20hiIxy/sMivUUcVTFYtK5cy2pQbQjVpPBDlMB8eZu4rjdfm5oTRPMJR6GlYbc8Ccudl38rlTj2FuwwE1w0EzHXMHRMXGzunZwpM/yVciKmeeznTGw36bcch86bA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=q8XcfZLV; 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="q8XcfZLV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2EC11C116B1; Thu, 25 Jul 2024 14:51:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721919112; bh=+P6flF0kanCxASEJFyAlazCsWInv1Xrq2TLRPhUxy74=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q8XcfZLVTrQ/e4cHXIsfz4X2ZtSc6MPrSDoG+u80059Tk3YUSPw516J/1QPsHe70K mI/hzTVfeJlDI9Xe/6uKMjyXwEzY4Gx5aiftC+K4CwjcNKj8Sym8oFEYZ8exn34Sq7 DRl0uHiCDCoXf1rnIIwExnYQDlseLO3ydE6eitGo= 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 5.15 27/87] kconfig: remove wrong expr_trans_bool() Date: Thu, 25 Jul 2024 16:37:00 +0200 Message-ID: <20240725142739.460589614@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240725142738.422724252@linuxfoundation.org> References: <20240725142738.422724252@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-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 81ebf8108ca74..81dfdf4470f75 100644 --- a/scripts/kconfig/expr.c +++ b/scripts/kconfig/expr.c @@ -396,35 +396,6 @@ 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 9c9caca5bd5f2..c91060e19e477 100644 --- a/scripts/kconfig/expr.h +++ b/scripts/kconfig/expr.h @@ -296,7 +296,6 @@ void expr_free(struct expr *e); void expr_eliminate_eq(struct expr **ep1, struct expr **ep2); int expr_eq(struct expr *e1, struct expr *e2); 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 606ba8a63c24e..8c53d9478be1f 100644 --- a/scripts/kconfig/menu.c +++ b/scripts/kconfig/menu.c @@ -380,8 +380,6 @@ 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