From: <Don.Brace@microchip.com>
To: natechancellor@gmail.com, axboe@kernel.dk, aacraid@microsemi.com,
jejb@linux.ibm.com, martin.petersen@oracle.com,
manoj@linux.ibm.com, mrochs@linux.ibm.com, ukrishn@linux.ibm.com,
linuxdrivers@attotech.com, don.brace@microsemi.com,
brking@us.ibm.com
Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-scsi@vger.kernel.org, esc.storagedev@microsemi.com,
ndesaulniers@google.com, bvanassche@acm.org
Subject: RE: [PATCH v4] scsi/ata: Use unsigned int for cmd's type in ioctls in scsi_host_template
Date: Mon, 28 Jan 2019 16:16:34 +0000 [thread overview]
Message-ID: <SN6PR11MB2767DF2A2BEF95EE07C15172E1960@SN6PR11MB2767.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20190126075256.29608-1-natechancellor@gmail.com>
Clang warns several times in the scsi subsystem (trimmed for brevity):
drivers/scsi/hpsa.c:6209:7: warning: overflow converting case value to switch condition type (2147762695 to 18446744071562347015) [-Wswitch]
case CCISS_GETBUSTYPES:
^
drivers/scsi/hpsa.c:6208:7: warning: overflow converting case value to switch condition type (2147762694 to 18446744071562347014) [-Wswitch]
case CCISS_GETHEARTBEAT:
^
The root cause is that the _IOC macro can generate really large numbers, which don't find into type 'int', which is used for the cmd paremeter in the ioctls in scsi_host_template. My research into how GCC and Clang are handling this at a low level didn't prove fruitful. However, looking at the rest of the kernel tree, all ioctls use an 'unsigned int' for the cmd parameter, which will fit all of the _IOC values in the scsi/ata subsystems.
Make that change because none of the ioctls expect to take a negative value, it brings the ioctls inline with the reset of the kernel, and it removes ambiguity, which is never good when dealing with compilers.
Link: https://github.com/ClangBuiltLinux/linux/issues/85
Link: https://github.com/ClangBuiltLinux/linux/issues/154
Link: https://github.com/ClangBuiltLinux/linux/issues/157
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
static void __exit esas2r_exit(void)
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index ff67ef5d5347..28cfd3d01c5a 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -251,10 +251,11 @@ static int number_of_controllers;
Acked-by: Don Brace <don.brace@microsemi.com>
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index f564af8949e8..5d9ccbab7581 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -6043,7 +6043,8 @@ static int pqi_passthru_ioctl(struct pqi_ctrl_info *ctrl_info, void __user *arg)
return rc;
}
Acked-by: Don Brace <don.brace@microsemi.com>
WARNING: multiple messages have this Message-ID (diff)
From: <Don.Brace@microchip.com>
To: <natechancellor@gmail.com>, <axboe@kernel.dk>,
<aacraid@microsemi.com>, <jejb@linux.ibm.com>,
<martin.petersen@oracle.com>, <manoj@linux.ibm.com>,
<mrochs@linux.ibm.com>, <ukrishn@linux.ibm.com>,
<linuxdrivers@attotech.com>, <don.brace@microsemi.com>,
<brking@us.ibm.com>
Cc: <linux-ide@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-scsi@vger.kernel.org>, <esc.storagedev@microsemi.com>,
<ndesaulniers@google.com>, <bvanassche@acm.org>
Subject: RE: [PATCH v4] scsi/ata: Use unsigned int for cmd's type in ioctls in scsi_host_template
Date: Mon, 28 Jan 2019 16:16:34 +0000 [thread overview]
Message-ID: <SN6PR11MB2767DF2A2BEF95EE07C15172E1960@SN6PR11MB2767.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20190126075256.29608-1-natechancellor@gmail.com>
Clang warns several times in the scsi subsystem (trimmed for brevity):
drivers/scsi/hpsa.c:6209:7: warning: overflow converting case value to switch condition type (2147762695 to 18446744071562347015) [-Wswitch]
case CCISS_GETBUSTYPES:
^
drivers/scsi/hpsa.c:6208:7: warning: overflow converting case value to switch condition type (2147762694 to 18446744071562347014) [-Wswitch]
case CCISS_GETHEARTBEAT:
^
The root cause is that the _IOC macro can generate really large numbers, which don't find into type 'int', which is used for the cmd paremeter in the ioctls in scsi_host_template. My research into how GCC and Clang are handling this at a low level didn't prove fruitful. However, looking at the rest of the kernel tree, all ioctls use an 'unsigned int' for the cmd parameter, which will fit all of the _IOC values in the scsi/ata subsystems.
Make that change because none of the ioctls expect to take a negative value, it brings the ioctls inline with the reset of the kernel, and it removes ambiguity, which is never good when dealing with compilers.
Link: https://github.com/ClangBuiltLinux/linux/issues/85
Link: https://github.com/ClangBuiltLinux/linux/issues/154
Link: https://github.com/ClangBuiltLinux/linux/issues/157
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
static void __exit esas2r_exit(void)
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c index ff67ef5d5347..28cfd3d01c5a 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -251,10 +251,11 @@ static int number_of_controllers;
Acked-by: Don Brace <don.brace@microsemi.com>
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index f564af8949e8..5d9ccbab7581 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -6043,7 +6043,8 @@ static int pqi_passthru_ioctl(struct pqi_ctrl_info *ctrl_info, void __user *arg)
return rc;
}
Acked-by: Don Brace <don.brace@microsemi.com>
next prev parent reply other threads:[~2019-01-28 16:16 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-19 17:57 [PATCH] scsi/ata: Use unsigned int for cmd's type in ioctls in scsi_host_template Nathan Chancellor
2018-10-19 19:38 ` Bart Van Assche
2018-10-20 4:52 ` kbuild test robot
2018-10-20 4:52 ` kbuild test robot
2018-10-20 5:01 ` [PATCH v2] " Nathan Chancellor
2018-12-17 17:31 ` Nathan Chancellor
2019-01-14 4:42 ` [PATCH v3] " Nathan Chancellor
2019-01-14 4:54 ` Bart Van Assche
2019-01-14 4:57 ` Nathan Chancellor
2019-01-26 7:52 ` [PATCH v4] " Nathan Chancellor
2019-01-26 9:19 ` Nick Desaulniers
2019-01-28 16:16 ` Don.Brace [this message]
2019-01-28 16:16 ` Don.Brace
2019-01-28 16:17 ` Nathan Chancellor
2019-02-05 18:42 ` Grove, Bradley
2019-02-07 10:52 ` Marc Gonzalez
2019-02-07 16:07 ` [PATCH v5] " Nathan Chancellor
2019-02-07 19:17 ` Nick Desaulniers
2019-02-08 8:05 ` Christoph Hellwig
2019-02-08 16:00 ` Nathan Chancellor
2019-02-08 22:33 ` Martin K. Petersen
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