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[2a02:3100:aeb3:cd01:f139:812c:65df:b930]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48de0bc50e0sm21915636f8f.49.2026.10.14.22.54.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Oct 2026 22:54:11 -0700 (PDT) Date: Thu, 15 Oct 2026 07:54:09 +0200 From: Karl Mehltretter To: Eddie James Cc: Ninad Palsule , Joel Stanley , linux-fsi@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] fsi: i2cr-scom: Return -EFAULT on usercopy failures Message-ID: References: <20260914062426.14140-1-kmehltretter@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: <20260914062426.14140-1-kmehltretter@gmail.com> On Mon, Sep 14, 2026 at 08:24:26AM +0100, Karl Mehltretter wrote: > copy_to_user() and copy_from_user() return the number of bytes that were > not copied. i2cr_scom_read() and i2cr_scom_write() return that value > directly, so a usercopy fault is reported as a successful short I/O. > > Return -EFAULT when either copy fails. > > A temporary KUnit test called i2cr_scom_write() with an invalid user > pointer. The unmodified kernel returned 8. With this change it returned > -EFAULT. Both versions were booted under QEMU. > > Fixes: c0b34bed0bbf ("fsi: Add I2C Responder SCOM driver") > Assisted-by: LLM > Signed-off-by: Karl Mehltretter A friendly ping on this usercopy error-handling fix. Thanks, Karl