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Thu, 12 Dec 2024 03:33:54 -0800 (PST) Date: Thu, 12 Dec 2024 12:33:51 +0100 From: Petr Mladek To: Kuan-Wei Chiu Cc: Steven Rostedt , John Ogness , Sergey Senozhatsky , Ching-Chun Huang , linux-kernel@vger.kernel.org Subject: Re: [PATCH] printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX Message-ID: References: <20240928113608.1438087-1-visitorckw@gmail.com> 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-Disposition: inline In-Reply-To: <20240928113608.1438087-1-visitorckw@gmail.com> On Sat 2024-09-28 19:36:08, Kuan-Wei Chiu wrote: > Shifting 1 << 31 on a 32-bit int causes signed integer overflow, which > leads to undefined behavior. To prevent this, cast 1 to u32 before > performing the shift, ensuring well-defined behavior. > > This change explicitly avoids any potential overflow by ensuring that > the shift occurs on an unsigned 32-bit integer. > > Signed-off-by: Kuan-Wei Chiu JFYI, the patch has been committed into printk/linux.git, branch for-6.14. Best Regards, Petr PS: I am terribly sorry for missing the merge window for 6.13. The patch went away from my radar and I have somehow missed even your reminder /o\