Re: [usb:usb-testing 54/97] drivers/usb/isp1760/isp1760-hcd.c:735:2: warning: Value stored to 'scratch' is never read [clang-analyzer-deadcode.DeadStores]
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-08-19 14:59:17
Also in:
oe-kbuild-all
On Thu, Aug 19, 2021 at 08:47:37AM +0100, Rui Miguel Silva wrote:
Hi, On Wed Aug 18, 2021 at 11:09 PM WEST, kernel test robot wrote:quoted
tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing head: e4788edc730a0d2b26e1ae1f08fbb3f635b92dbb commit: 7de14c88272c05d86fce83a5cead36832ce3a424 [54/97] usb: isp1760: remove debug message as error config: riscv-randconfig-c006-20210818 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project d2b574a4dea5b718e4386bf2e26af0126e5978ce) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/commit/?id=7de14c88272c05d86fce83a5cead36832ce3a424 git remote add usb https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git git fetch --no-tags usb usb-testing git checkout 7de14c88272c05d86fce83a5cead36832ce3a424 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv clang-analyzer If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <redacted> clang-analyzer warnings: (new ones prefixed by >>) ^ ~ drivers/target/target_core_configfs.c:2627:23: warning: Value stored to 'alua_lu_gp_cg' during its initialization is never read [clang-analyzer-deadcode.DeadStores] struct config_group *alua_lu_gp_cg = &lu_gp->lu_gp_group; ^~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~ drivers/target/target_core_configfs.c:2627:23: note: Value stored to 'alua_lu_gp_cg' during its initialization is never read struct config_group *alua_lu_gp_cg = &lu_gp->lu_gp_group; ^~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~ drivers/target/target_core_configfs.c:2731:2: warning: Value stored to 'alua_lu_gp_ci' is never read [clang-analyzer-deadcode.DeadStores] alua_lu_gp_ci = &alua_lu_gp_cg->cg_item; ^ ~~~~~~~~~~~~~~~~~~~~~~~ drivers/target/target_core_configfs.c:2731:2: note: Value stored to 'alua_lu_gp_ci' is never read alua_lu_gp_ci = &alua_lu_gp_cg->cg_item; ^ ~~~~~~~~~~~~~~~~~~~~~~~ drivers/target/target_core_configfs.c:2748:25: warning: Value stored to 'lu_gp' during its initialization is never read [clang-analyzer-deadcode.DeadStores] struct t10_alua_lu_gp *lu_gp = container_of(to_config_group(item), ^~~~~ drivers/target/target_core_configfs.c:2748:25: note: Value stored to 'lu_gp' during its initialization is never read struct t10_alua_lu_gp *lu_gp = container_of(to_config_group(item), ^~~~~ drivers/target/target_core_configfs.c:3026:23: warning: Value stored to 'alua_tg_pt_gp_cg' during its initialization is never read [clang-analyzer-deadcode.DeadStores] struct config_group *alua_tg_pt_gp_cg = &tg_pt_gp->tg_pt_gp_group; ^~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/target/target_core_configfs.c:3026:23: note: Value stored to 'alua_tg_pt_gp_cg' during its initialization is never read struct config_group *alua_tg_pt_gp_cg = &tg_pt_gp->tg_pt_gp_group; ^~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/target/target_core_configfs.c:3163:2: warning: Value stored to 'alua_tg_pt_gp_ci' is never read [clang-analyzer-deadcode.DeadStores] alua_tg_pt_gp_ci = &alua_tg_pt_gp_cg->cg_item; ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/target/target_core_configfs.c:3163:2: note: Value stored to 'alua_tg_pt_gp_ci' is never read alua_tg_pt_gp_ci = &alua_tg_pt_gp_cg->cg_item; ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/target/target_core_configfs.c:3179:28: warning: Value stored to 'tg_pt_gp' during its initialization is never read [clang-analyzer-deadcode.DeadStores] struct t10_alua_tg_pt_gp *tg_pt_gp = container_of(to_config_group(item), ^~~~~~~~ drivers/target/target_core_configfs.c:3179:28: note: Value stored to 'tg_pt_gp' during its initialization is never read struct t10_alua_tg_pt_gp *tg_pt_gp = container_of(to_config_group(item), ^~~~~~~~ Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 6 warnings generated. drivers/misc/eeprom/at24.c:334:2: warning: Value stored to 'client' is never read [clang-analyzer-deadcode.DeadStores] client = at24_client->client; ^ ~~~~~~~~~~~~~~~~~~~ drivers/misc/eeprom/at24.c:334:2: note: Value stored to 'client' is never read client = at24_client->client; ^ ~~~~~~~~~~~~~~~~~~~ drivers/misc/eeprom/at24.c:397:2: warning: Value stored to 'client' is never read [clang-analyzer-deadcode.DeadStores] client = at24_client->client; ^ ~~~~~~~~~~~~~~~~~~~ drivers/misc/eeprom/at24.c:397:2: note: Value stored to 'client' is never read client = at24_client->client; ^ ~~~~~~~~~~~~~~~~~~~ Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 5 warnings generated. drivers/usb/isp1760/isp1760-core.c:490:2: warning: Value stored to 'udc_enabled' is never read [clang-analyzer-deadcode.DeadStores] udc_enabled = ((devflags & ISP1760_FLAG_ISP1763) || ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/usb/isp1760/isp1760-core.c:490:2: note: Value stored to 'udc_enabled' is never read udc_enabled = ((devflags & ISP1760_FLAG_ISP1763) || ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 4 warnings generated. Suppressed 4 warnings (4 in non-user code). Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well. 9 warnings generated.quoted
quoted
drivers/usb/isp1760/isp1760-hcd.c:735:2: warning: Value stored to 'scratch' is never read [clang-analyzer-deadcode.DeadStores]scratch = isp1760_hcd_read(hcd, HC_CHIP_ID_HIGH); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~yeah, this is desired behaviour, this read is only to make sure that we make something different than the pattern to test go over the bus. However I will take a look to this warning and other clang warnings that I am seeing in this report.
This is why I hate this type of warning, doing a read like this is totally normal for drivers. Compilers that think this is something they can ignore or warn about are just wrong. greg k-h