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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 53282C282CB for ; Fri, 8 Feb 2019 15:24:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21A222146E for ; Fri, 8 Feb 2019 15:24:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728182AbfBHPYt (ORCPT ); Fri, 8 Feb 2019 10:24:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:60044 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728097AbfBHPY3 (ORCPT ); Fri, 8 Feb 2019 10:24:29 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id A2ACAB145; Fri, 8 Feb 2019 15:24:27 +0000 (UTC) From: Petr Mladek To: Andy Shevchenko , Rasmus Villemoes Cc: Linus Torvalds , "Tobin C . Harding" , Joe Perches , Andrew Morton , Michal Hocko , Sergey Senozhatsky , Steven Rostedt , Sergey Senozhatsky , linux-kernel@vger.kernel.org, Petr Mladek Subject: [PATCH v6 7/9] vsprintf: Consolidate handling of unknown pointer specifiers Date: Fri, 8 Feb 2019 16:23:08 +0100 Message-Id: <20190208152310.29531-8-pmladek@suse.com> X-Mailer: git-send-email 2.13.7 In-Reply-To: <20190208152310.29531-1-pmladek@suse.com> References: <20190208152310.29531-1-pmladek@suse.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are few printk formats that make sense only with two or more specifiers. Also some specifiers make sense only when a kernel feature is enabled. The handling of unknown specifiers is inconsistent and not helpful. Using WARN() looks like an overkill for this type of error. pr_warn() is not good either. It would by handled via printk_safe buffer and it might be hard to match it with the problematic string. A reasonable compromise seems to be writing the unknown format specifier into the original string with a question mark, for example (%pC?). It should be self-explaining enough. Note that it is in brackets to follow the (null) style. Note that the changes in test_printf.c revert many changes made by the commit 4d42c44727a062e233 ("lib/vsprintf: Print time and date in human readable format via %pt\n"). The format %pt does not longer produce a hashed pointer. Signed-off-by: Petr Mladek --- lib/test_printf.c | 39 ++++----------------------------------- lib/vsprintf.c | 28 +++++++++++++++++----------- 2 files changed, 21 insertions(+), 46 deletions(-) diff --git a/lib/test_printf.c b/lib/test_printf.c index 659b6cc0d483..159bb78b3992 100644 --- a/lib/test_printf.c +++ b/lib/test_printf.c @@ -250,11 +250,12 @@ plain_format(void) #endif /* BITS_PER_LONG == 64 */ static int __init -plain_hash_to_buffer(const void *p, char *buf, size_t len) +plain_hash(void) { + char buf[PLAIN_BUF_SIZE]; int nchars; - nchars = snprintf(buf, len, "%p", p); + nchars = snprintf(buf, sizeof(buf), "%p", PTR); if (nchars != PTR_WIDTH) return -1; @@ -265,20 +266,6 @@ plain_hash_to_buffer(const void *p, char *buf, size_t len) return 0; } - return 0; -} - - -static int __init -plain_hash(void) -{ - char buf[PLAIN_BUF_SIZE]; - int ret; - - ret = plain_hash_to_buffer(PTR, buf, PLAIN_BUF_SIZE); - if (ret) - return ret; - if (strncmp(buf, PTR_STR, PTR_WIDTH) == 0) return -1; @@ -309,23 +296,6 @@ plain(void) } static void __init -test_hashed(const char *fmt, const void *p) -{ - char buf[PLAIN_BUF_SIZE]; - int ret; - - /* - * No need to increase failed test counter since this is assumed - * to be called after plain(). - */ - ret = plain_hash_to_buffer(p, buf, PLAIN_BUF_SIZE); - if (ret) - return; - - test(buf, fmt, p); -} - -static void __init symbol_ptr(void) { } @@ -462,8 +432,7 @@ struct_rtc_time(void) .tm_year = 118, }; - test_hashed("%pt", &tm); - + test("(%ptR?)", "%pt", &tm); test("2018-11-26T05:35:43", "%ptR", &tm); test("0118-10-26T05:35:43", "%ptRr", &tm); test("05:35:43|2018-11-26", "%ptRt|%ptRd", &tm, &tm); diff --git a/lib/vsprintf.c b/lib/vsprintf.c index ab59db1c1146..d8509f6adda6 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1434,6 +1434,8 @@ static noinline_for_stack char *ip_addr_string(char *buf, char *end, const void *ptr, struct printf_spec spec, const char *fmt) { + char *err_fmt_msg; + switch (fmt[1]) { case '6': return ip6_addr_string(buf, end, ptr, spec, fmt); @@ -1456,7 +1458,8 @@ char *ip_addr_string(char *buf, char *end, const void *ptr, }} } - return ptr_to_id(buf, end, ptr, spec); + err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)"; + return string_nocheck(buf, end, err_fmt_msg, spec); } static noinline_for_stack @@ -1584,7 +1587,7 @@ char *netdev_bits(char *buf, char *end, const void *addr, size = sizeof(netdev_features_t); break; default: - return ptr_to_id(buf, end, addr, spec); + return string_nocheck(buf, end, "(%pN?)", spec); } return special_hex_number(buf, end, num, size); @@ -1688,7 +1691,7 @@ char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, case 'R': return rtc_str(buf, end, (const struct rtc_time *)ptr, fmt); default: - return ptr_to_id(buf, end, ptr, spec); + return string_nocheck(buf, end, "(%ptR?)", spec); } } @@ -1696,7 +1699,10 @@ static noinline_for_stack char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, const char *fmt) { - if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk) + if (!IS_ENABLED(CONFIG_HAVE_CLK)) + return string_nocheck(buf, end, "(%pC?)", spec); + + if (!clk) return string(buf, end, NULL, spec); switch (fmt[1]) { @@ -1705,7 +1711,7 @@ char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, #ifdef CONFIG_COMMON_CLK return string(buf, end, __clk_get_name(clk), spec); #else - return ptr_to_id(buf, end, clk, spec); + return string_nocheck(buf, end, "(%pC?)", spec); #endif } } @@ -1738,7 +1744,8 @@ char *format_flags(char *buf, char *end, unsigned long flags, } static noinline_for_stack -char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt) +char *flags_string(char *buf, char *end, void *flags_ptr, + struct printf_spec spec, const char *fmt) { unsigned long flags; const struct trace_print_flags *names; @@ -1759,8 +1766,7 @@ char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt) names = gfpflag_names; break; default: - WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]); - return buf; + return string_nocheck(buf, end, "(%pG?)", spec); } return format_flags(buf, end, flags, names); @@ -1816,7 +1822,7 @@ char *device_node_string(char *buf, char *end, struct device_node *dn, str_spec.field_width = -1; if (!IS_ENABLED(CONFIG_OF)) - return string_nocheck(buf, end, "(!OF)", spec); + return string_nocheck(buf, end, "(%pOF?)", spec); if ((unsigned long)dn < PAGE_SIZE) return string_nocheck(buf, end, "(null)", spec); @@ -1895,7 +1901,7 @@ static char *kobject_string(char *buf, char *end, void *ptr, return device_node_string(buf, end, ptr, spec, fmt + 1); } - return ptr_to_id(buf, end, ptr, spec); + return string_nocheck(buf, end, "(%pO?)", spec); } /* @@ -2091,7 +2097,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, #endif case 'G': - return flags_string(buf, end, ptr, fmt); + return flags_string(buf, end, ptr, spec, fmt); case 'O': return kobject_string(buf, end, ptr, spec, fmt); case 'x': -- 2.13.7