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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-487270af027sm31353835e9.3.2026.03.27.09.08.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Mar 2026 09:09:00 -0700 (PDT) Date: Fri, 27 Mar 2026 16:08:58 +0000 From: David Laight To: Andy Shevchenko Cc: Theodore Ts'o , Andreas Dilger , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, Masami Hiramatsu , Petr Mladek , Rasmus Villemoes , Steven Rostedt , Sergey Senozhatsky , Andrew Morton Subject: Re: [PATCH next] ext4: Fix diagnostic printf formats Message-ID: <20260327160858.233399bb@pumpkin> In-Reply-To: References: <20260326201804.3881-1-david.laight.linux@gmail.com> <20260327125412.47944386@pumpkin> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 27 Mar 2026 16:12:38 +0200 Andy Shevchenko wrote: ... > P.S. A bit of off-topic, have you seen this? > https://elixir.bootlin.com/linux/v7.0-rc5/source/kernel/stacktrace.c#L33 > Is it correct use of %c? > Works with glibc (or, rather, with whichever libc the shell I'm using is linked against): $ printf '|%*c|\n' 5 x | x| $ 'man fprintf' tends to agree. Left justify also works, either "%-*c" or passing -5. The 'fun' starts if you print a zero with %c in the middle of some output. I know some compilers have supported: int c = 'abcd'; But I can't remember whether the value could be printed with %4c. I do remember that the value ended up byteswapped in memory on both x86 and sparc. David