From nobody Sat Apr 11 21:14:18 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D49BC19F2A for ; Mon, 8 Aug 2022 02:43:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244120AbiHHCnO (ORCPT ); Sun, 7 Aug 2022 22:43:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32802 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242536AbiHHClm (ORCPT ); Sun, 7 Aug 2022 22:41:42 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C166521BA for ; Sun, 7 Aug 2022 19:41:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=gLSmP0ezGtWML91IudXrNJu8Zj7NmJrDaiBCbrXz+LY=; b=MTuHy9VnQfrt2AB+/dowXbi0Xl p/HsStgU1cVih1U6rA3n+lDtpLxkQnEfX/PJ9DCqQLl9dmaOeL+IMDfMclxATrkBqZTJk/yVL/+ym Dvi5FrLyOGSBglGfyE/fmAK0psd/SAOf5CAfd3w9Z/A5ArMZft9EED/FgJU4F4LRVUfRe1SK5244n UUvRaRG11eBhZWsSXwpHo+I6f5EiRjAR6j1EeEqIwctpKDo3WCeDhq3bvz33d4T13V9/H775it6jV grcDXX65Gl6/qi6bkwITzFZo3MNtqHnXmRWWQyCYi+agf/UoME3pil5+McLv7ZUCHL3s2YoiV0fUN XtBiz4Lw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oKshy-00DVS2-56; Mon, 08 Aug 2022 02:41:34 +0000 From: "Matthew Wilcox (Oracle)" To: linux-kernel@vger.kernel.org, pmladek@suse.com, Kent Overstreet Cc: Rasmus Villemoes Subject: [PATCH v5 19/32] vsprintf: Refactor device_node_string, fwnode_string Date: Mon, 8 Aug 2022 03:41:15 +0100 Message-Id: <20220808024128.3219082-20-willy@infradead.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220808024128.3219082-1-willy@infradead.org> References: <20220808024128.3219082-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Kent Overstreet - eliminate on-stack buffer in device_node_string - eliminate unnecessary uses of printf_spec, lift format string precision/field width to pointer() Signed-off-by: Kent Overstreet Cc: Petr Mladek Cc: Rasmus Villemoes --- lib/vsprintf.c | 73 ++++++++++++++++++++------------------------------ 1 file changed, 29 insertions(+), 44 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 38d16aa79e56..06cfa06aa4ee 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1963,25 +1963,20 @@ void fwnode_full_name_string(struct printbuf *out, =20 static noinline_for_stack void device_node_string(struct printbuf *out, struct device_node *dn, - struct printf_spec spec, const char *fmt) + const char *fmt) { - char tbuf[sizeof("xxxx") + 1]; const char *p; int ret; - unsigned start =3D out->pos; struct property *prop; bool has_mult, pass; =20 - struct printf_spec str_spec =3D spec; - str_spec.field_width =3D -1; - if (fmt[0] !=3D 'F') - return error_string_spec(out, "(%pO?)", spec); + return error_string(out, "(%pO?)"); =20 if (!IS_ENABLED(CONFIG_OF)) - return error_string_spec(out, "(%pOF?)", spec); + return error_string(out, "(%pOF?)"); =20 - if (check_pointer_spec(out, dn, spec)) + if (check_pointer(out, dn)) return; =20 /* simple case without anything any more format specifiers */ @@ -1990,7 +1985,6 @@ void device_node_string(struct printbuf *out, struct = device_node *dn, fmt =3D "f"; =20 for (pass =3D false; strspn(fmt,"fnpPFcC"); fmt++, pass =3D true) { - int precision; if (pass) prt_char(out, ':'); =20 @@ -1998,43 +1992,41 @@ void device_node_string(struct printbuf *out, struc= t device_node *dn, case 'f': /* full_name */ fwnode_full_name_string(out, of_fwnode_handle(dn)); break; - case 'n': /* name */ - p =3D fwnode_get_name(of_fwnode_handle(dn)); - precision =3D str_spec.precision; - str_spec.precision =3D strchrnul(p, '@') - p; - string_spec(out, p, str_spec); - str_spec.precision =3D precision; + case 'n': { /* name */ + const char *name =3D fwnode_get_name(of_fwnode_handle(dn)); + unsigned len =3D strchrnul(name, '@') - name; + + prt_bytes(out, name, len); break; + } case 'p': /* phandle */ - prt_u64(out, (unsigned int)dn->phandle); + prt_u64(out, dn->phandle); break; case 'P': /* path-spec */ p =3D fwnode_get_name(of_fwnode_handle(dn)); if (!p[1]) p =3D "/"; - string_spec(out, p, str_spec); + string(out, p); break; case 'F': /* flags */ - tbuf[0] =3D of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; - tbuf[1] =3D of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; - tbuf[2] =3D of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; - tbuf[3] =3D of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; - tbuf[4] =3D 0; - string_nocheck(out, tbuf, str_spec); + prt_char(out, of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'); + prt_char(out, of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'); + prt_char(out, of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'); + prt_char(out, of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'); break; case 'c': /* major compatible string_spec */ ret =3D of_property_read_string(dn, "compatible", &p); if (!ret) - string_spec(out, p, str_spec); + string(out, p); break; case 'C': /* full compatible string_spec */ has_mult =3D false; of_property_for_each_string(dn, "compatible", prop, p) { if (has_mult) - string_nocheck(out, ",", str_spec); - string_nocheck(out, "\"", str_spec); - string_spec(out, p, str_spec); - string_nocheck(out, "\"", str_spec); + prt_char(out, ','); + prt_char(out, '\"'); + string(out, p); + prt_char(out, '\"'); =20 has_mult =3D true; } @@ -2043,39 +2035,30 @@ void device_node_string(struct printbuf *out, struc= t device_node *dn, break; } } - - widen_string(out, out->pos - start, spec); } =20 static noinline_for_stack void fwnode_string(struct printbuf *out, struct fwnode_handle *fwnode, - struct printf_spec spec, const char *fmt) + const char *fmt) { - struct printf_spec str_spec =3D spec; - unsigned start =3D out->pos; - - str_spec.field_width =3D -1; - if (*fmt !=3D 'w') - return error_string_spec(out, "(%pf?)", spec); + return error_string(out, "(%pf?)"); =20 - if (check_pointer_spec(out, fwnode, spec)) + if (check_pointer(out, fwnode)) return; =20 fmt++; =20 switch (*fmt) { case 'P': /* name */ - string_spec(out, fwnode_get_name(fwnode), str_spec); + string(out, fwnode_get_name(fwnode)); break; case 'f': /* full_name */ default: fwnode_full_name_string(out, fwnode); break; } - - widen_string(out, out->pos - start, spec); } =20 int __init no_hash_pointers_enable(char *str) @@ -2313,9 +2296,11 @@ void pointer(struct printbuf *out, const char *fmt, flags_string(out, ptr, fmt); return do_width_precision(out, prev_pos, spec); case 'O': - return device_node_string(out, ptr, spec, fmt + 1); + device_node_string(out, ptr, fmt + 1); + return do_width_precision(out, prev_pos, spec); case 'f': - return fwnode_string(out, ptr, spec, fmt + 1); + fwnode_string(out, ptr, fmt + 1); + return do_width_precision(out, prev_pos, spec); case 'x': return pointer_string(out, ptr, spec); case 'e': --=20 2.35.1