From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cyril Roelandt Date: Thu, 22 Nov 2012 00:05:30 +0000 Subject: Re: [PATCH] acpi_system_write_wakeup_device(): fix error check for unsigned variable. Message-Id: <50AD6C4A.4030809@gmail.com> List-Id: References: <1353117263-6957-1-git-send-email-tipecaml@gmail.com> <1732852.VDXGV3Ao2T@vostro.rjw.lan> In-Reply-To: <1732852.VDXGV3Ao2T@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Rafael J. Wysocki" Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, lenb@kernel.org, kernel-janitors@vger.kernel.org On 11/21/2012 01:44 AM, Rafael J. Wysocki wrote: > On Saturday, November 17, 2012 02:54:23 AM Cyril Roelandt wrote: >> The LEN variable is unsigned, therefore checking whether it is less than 0 is >> useless. >> >> Signed-off-by: Cyril Roelandt >> --- >> drivers/acpi/proc.c | 2 -- >> 1 file changed, 2 deletions(-) >> >> diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c >> index 27adb09..37871a7 100644 >> --- a/drivers/acpi/proc.c >> +++ b/drivers/acpi/proc.c >> @@ -366,8 +366,6 @@ acpi_system_write_wakeup_device(struct file *file, >> >> if (len> 4) >> len = 4; >> - if (len< 0) >> - return -EFAULT; > > I would prefer to check if count< 0 instead. > count has type size_t, so it is also an unsigned variable. I think that acpi_system_write_wakeup_device really cannot be called with a "count" parameter that is less than 0. WBR, Cyril Roelandt.