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[209.132.180.67]) by mx.google.com with ESMTP id h125si870009oia.253.2020.03.04.03.14.28; Wed, 04 Mar 2020 03:14:40 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=E5i5pswg; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387761AbgCDLOZ (ORCPT + 99 others); Wed, 4 Mar 2020 06:14:25 -0500 Received: from mail-wr1-f66.google.com ([209.85.221.66]:46290 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726137AbgCDLOZ (ORCPT ); Wed, 4 Mar 2020 06:14:25 -0500 Received: by mail-wr1-f66.google.com with SMTP id j7so1858541wrp.13 for ; Wed, 04 Mar 2020 03:14:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=ytJyZne6tZeakYNWCLvFS4U17Dxs6Z9j14ft6YAqs1Y=; b=E5i5pswg8Xz0wg1+iNVXwEiKmUyrezTIOvhxCawnzSfY7oSbglTIWwQ0fgct0doFOi mX+7kSfBVuPVFpPEzCEhDEhh8GRrgD7j3tcFB/LdMVYLhvEBIouIGY6Njh19ca9EDkKJ d6Bd79K4jVPC5eHh9WqltbZ+JYvFwDPe7mnhnLO9oUS9ucehEhKqGvMgvjO8pPBRtD+h NPNWOeh7FQ0sF2/HHfhwoNJwe0fRGCRfjz15HiKDhYbDBI/pBxD8kUJgL6hDMuqW+kKH dldnc7ZSthkpYEydmwGC1M4kEc8foQKPUPsF/QFx2DA77PKyWN6EHOgatRhJAneAzk2e SsiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=ytJyZne6tZeakYNWCLvFS4U17Dxs6Z9j14ft6YAqs1Y=; b=fLC21giaaD/hwbVG8uQIcXIjTygebTYyGXWtOVeK2h1dr6BM+4Vw/rz4j4VcHUoLHH FeE9JZWzIElDe3rfQ67wvNa362FvX9pxYnKWZ3/Df+1zeKuMywFfTcw24cDAaUa5OZT8 0ND5n2dvxcEGBQRPbPsNMe1XfTb26gqkHWPFrHh9me3kNs+SDXjn4UJlLVjzt0Y80mSO khfFG2CKUXYFq38qJVxe0Mbi1BsaxCU7HxMr5nZM6rs9onPTNij4Wt7vBI+Y1C56S1o2 kmrzQD2V2mK4dWI+fz3elN0NYh9fNxSNVwVL0lKPKMLbNuA+VtOJSE5daAtrQYnSPvPR 2t2A== X-Gm-Message-State: ANhLgQ0JNzt3dUkYj9YPQijsZB9N08XgJlZ9LFSXFgrF4hm62/FT3Ivq HrfMMhVn7VEsYvdTtD87ip09Xw== X-Received: by 2002:a5d:4f12:: with SMTP id c18mr3597686wru.329.1583320463015; Wed, 04 Mar 2020 03:14:23 -0800 (PST) Received: from google.com ([2a00:79e0:d:210:e8f7:125b:61e9:733d]) by smtp.gmail.com with ESMTPSA id 133sm3877459wmd.5.2020.03.04.03.14.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Mar 2020 03:14:22 -0800 (PST) Date: Wed, 4 Mar 2020 11:14:22 +0000 From: Matthias Maennich To: Jessica Yu Cc: Masahiro Yamada , Joe Perches , Linux Kernel Mailing List Subject: Re: [PATCH v2 1/2] modpost: rework and consolidate logging interface Message-ID: <20200304111422.GA66900@google.com> References: <20200226142608.19499-1-jeyu@kernel.org> <20200303145736.GA16460@linux-8ccs> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200303145736.GA16460@linux-8ccs> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 03, 2020 at 03:57:36PM +0100, Jessica Yu wrote: >+++ Masahiro Yamada [03/03/20 23:42 +0900]: >>On Wed, Feb 26, 2020 at 11:26 PM Jessica Yu wrote: >>> >>>Rework modpost's logging interface by consolidating merror(), warn(), >>>and fatal() to use a single function, modpost_log(). Introduce different >>>logging levels (WARN, ERROR, FATAL) as well as a conditional warn >>>(warn_unless()). The conditional warn is useful in determining whether >>>to use merror() or warn() based on a condition. This reduces code >>>duplication overall. >>> >>>Signed-off-by: Jessica Yu >>>--- >>>v2: >>> - modpost_log: initialize level to "" >>> - remove parens () from case labels >>> >>> scripts/mod/modpost.c | 69 +++++++++++++++++++++++---------------------------- >>> scripts/mod/modpost.h | 22 +++++++++++++--- >>> 2 files changed, 50 insertions(+), 41 deletions(-) >>> >>>diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c >>>index 7edfdb2f4497..3201a2ac5cc4 100644 >>>--- a/scripts/mod/modpost.c >>>+++ b/scripts/mod/modpost.c >>>@@ -51,41 +51,37 @@ enum export { >>> >>> #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr)) >>> >>>-#define PRINTF __attribute__ ((format (printf, 1, 2))) >>>+#define PRINTF __attribute__ ((format (printf, 2, 3))) >>> >>>-PRINTF void fatal(const char *fmt, ...) >>>+PRINTF void modpost_log(enum loglevel loglevel, const char *fmt, ...) >>> { >>>+ char *level = ""; >> >> >>You can add 'const'. >> >> >> const char *level = ""; >> >> >> >>> va_list arglist; >>> >>>- fprintf(stderr, "FATAL: "); >>>- >>>- va_start(arglist, fmt); >>>- vfprintf(stderr, fmt, arglist); >>>- va_end(arglist); >>>- >>>- exit(1); >>>-} >>>- >>>-PRINTF void warn(const char *fmt, ...) >>>-{ >>>- va_list arglist; >>>+ switch(loglevel) { >>>+ case LOG_WARN: >>>+ level = "WARNING: "; >>>+ break; >>>+ case LOG_ERROR: >>>+ level = "ERROR: "; >>>+ break; >>>+ case LOG_FATAL: >>>+ level = "FATAL: "; >>>+ break; >>>+ default: /* invalid loglevel, ignore */ >>>+ break; >>>+ } >>> >>>- fprintf(stderr, "WARNING: "); >>>+ fprintf(stderr, level); >> >> >> >>If I apply this patch, I see this warning: >> >>scripts/mod/modpost.c: In function ‘modpost_log’: >>scripts/mod/modpost.c:77:2: warning: format not a string literal and >>no format arguments [-Wformat-security] >> fprintf(stderr, level); >> ^~~~~~~ >> >> >>Please write like this: >> >> >> fprintf(stderr, "%s", level); >> >> >> >> >>Or, you can delete 'level', then write >>string literals directly in fprintf(). >> >> >>switch(loglevel) { >>case LOG_WARN: >> fprintf(stderr, "WARNING: "); >> break; >>case LOG_ERROR: >> fprintf(stderr, "ERROR: "); >> break; >>case LOG_FATAL: >> fprintf(stderr, "FATAL: "); >> break; >>} >> >> >> >> >>>+ fprintf(stderr, "modpost: "); >>> >>> va_start(arglist, fmt); >>> vfprintf(stderr, fmt, arglist); >>> va_end(arglist); >>>-} >>> >> >> >> >>>diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h >>>index 64a82d2d85f6..631d07714f7a 100644 >>>--- a/scripts/mod/modpost.h >>>+++ b/scripts/mod/modpost.h >>>@@ -198,6 +198,22 @@ void *grab_file(const char *filename, unsigned long *size); >>> char* get_next_line(unsigned long *pos, void *file, unsigned long size); >>> void release_file(void *file, unsigned long size); >>> >>>-void fatal(const char *fmt, ...); >>>-void warn(const char *fmt, ...); >>>-void merror(const char *fmt, ...); >>>+enum loglevel { >>>+ LOG_WARN, >>>+ LOG_ERROR, >>>+ LOG_FATAL >>>+}; >>>+ >>>+void modpost_log(enum loglevel loglevel, const char *fmt, ...); >>>+ >>>+#define warn(fmt, args...) modpost_log(LOG_WARN, fmt, ##args) >>>+#define merror(fmt, args...) modpost_log(LOG_ERROR, fmt, ##args) The only thing that bothered me a bit was the inconsistent naming with 'merror'. I know `error` is reserved, but refactoring this whole code (thanks for that!) seems like a code opportunity to clean this up. (Or is it just me?) Cheers, Matthias >>>+#define fatal(fmt, args...) modpost_log(LOG_FATAL, fmt, ##args) >>>+/* Warn unless condition is true, then use merror() */ >>>+#define warn_unless(condition, fmt, args...) \ >>>+do { \ >>>+ if (condition) \ >>>+ merror(fmt, ##args); \ >>>+ else \ >>>+ warn(fmt, ##args); \ >>>+} while (0) >> >> >>Hmm, warn_unless() is not intuitive naming... >> >>You could use modpost_log() directly in C code, >>what do you think? >> >> >> modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR, >> "module %s uses symbol %s from namespace %s, >>but does not import it.\n", >> basename, exp->name, exp->namespace); > >Yeah, I wasn't sure if I should expose modpost_log() and call it >directly, so I wrapped it in warn_unless(). But I think it's not a big >deal, so I'll just change it to a direct call. Thank you for the review! > >Jessica