drivers/gpio/gpio-virtio.c:23:8: warning: Excessive padding in 'struct virtio_gpio_line' (58 padding bytes, where 26 is optimal). Optimal fields order: res, rxlen, lock, completion, req, consider reordering the fields or adding explicit padding members [c...

From: kernel test robot
Date: Sat Jul 02 2022 - 20:04:02 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 69cb6c6556ad89620547318439d6be8bb1629a5a
commit: 3a29355a22c0275fe864100794fee58a73175d93 gpio: Add virtio-gpio driver
date: 10 months ago
config: arm-randconfig-c002-20220629 (https://download.01.org/0day-ci/archive/20220703/202207030712.4FJHaNfk-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a9119143a2d1f4d0d0bc1fe0d819e5351b4e0deb)
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 arm cross compiling tool for clang build
# apt-get install binutils-arm-linux-gnueabi
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3a29355a22c0275fe864100794fee58a73175d93
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 3a29355a22c0275fe864100794fee58a73175d93
# save the config file
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm clang-analyzer

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>


clang-analyzer warnings: (new ones prefixed by >>)
^
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
crypto/skcipher.c:354:10: note: Assuming '__UNIQUE_ID___x333' is >= '__UNIQUE_ID___y334'
bsize = min(walk->stride, max(n, walk->blocksize));
^
include/linux/minmax.h:45:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^~~~~~~~~~
crypto/skcipher.c:354:10: note: '?' condition is false
bsize = min(walk->stride, max(n, walk->blocksize));
^
include/linux/minmax.h:45:19: note: expanded from macro 'min'
#define min(x, y) __careful_cmp(x, y, <)
^
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
crypto/skcipher.c:358:15: note: Assuming 'n' is < 'bsize'
if (unlikely(n < bsize)) {
^
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
crypto/skcipher.c:358:2: note: Taking true branch
if (unlikely(n < bsize)) {
^
crypto/skcipher.c:359:22: note: Field 'total' is < field 'blocksize'
if (unlikely(walk->total < walk->blocksize))
^
crypto/skcipher.c:359:3: note: Taking true branch
if (unlikely(walk->total < walk->blocksize))
^
crypto/skcipher.c:360:11: note: Calling 'skcipher_walk_done'
return skcipher_walk_done(walk, -EINVAL);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
crypto/skcipher.c:110:6: note: Assuming 'n' is not equal to 0
if (!n)
^~
crypto/skcipher.c:110:2: note: Taking false branch
if (!n)
^
crypto/skcipher.c:113:2: note: Taking false branch
if (likely(err >= 0)) {
^
crypto/skcipher.c:118:13: note: Assuming the condition is false
if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
^
include/linux/compiler.h:77:40: note: expanded from macro 'likely'
# define likely(x) __builtin_expect(!!(x), 1)
^
crypto/skcipher.c:118:2: note: Taking false branch
if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
^
crypto/skcipher.c:124:13: note: Assuming the condition is false
} else if (walk->flags & SKCIPHER_WALK_DIFF) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
crypto/skcipher.c:124:9: note: Taking false branch
} else if (walk->flags & SKCIPHER_WALK_DIFF) {
^
crypto/skcipher.c:127:13: note: Assuming the condition is true
} else if (walk->flags & SKCIPHER_WALK_COPY) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
crypto/skcipher.c:127:9: note: Taking true branch
} else if (walk->flags & SKCIPHER_WALK_COPY) {
^
crypto/skcipher.c:128:3: note: Calling 'skcipher_map_dst'
skcipher_map_dst(walk);
^~~~~~~~~~~~~~~~~~~~~~
crypto/skcipher.c:67:1: note: Returning without writing to 'walk->page'
}
^
crypto/skcipher.c:128:3: note: Returning from 'skcipher_map_dst'
skcipher_map_dst(walk);
^~~~~~~~~~~~~~~~~~~~~~
crypto/skcipher.c:129:3: note: Null pointer passed as 2nd argument to memory copy function
memcpy(walk->dst.virt.addr, walk->page, n);
^ ~~~~~~~~~~
Suppressed 1 warnings (1 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.
1 warning generated.
Suppressed 1 warnings (1 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.
1 warning generated.
>> drivers/gpio/gpio-virtio.c:23:8: warning: Excessive padding in 'struct virtio_gpio_line' (58 padding bytes, where 26 is optimal). Optimal fields order: res, rxlen, lock, completion, req, consider reordering the fields or adding explicit padding members [clang-analyzer-optin.performance.Padding]
struct virtio_gpio_line {
~~~~~~~^~~~~~~~~~~~~~~~~~
drivers/gpio/gpio-virtio.c:23:8: note: Excessive padding in 'struct virtio_gpio_line' (58 padding bytes, where 26 is optimal). Optimal fields order: res, rxlen, lock, completion, req, consider reordering the fields or adding explicit padding members
struct virtio_gpio_line {
~~~~~~~^~~~~~~~~~~~~~~~~~
1 warning generated.
drivers/pwm/core.c:818:13: warning: Access to field 'name' results in a dereference of a null pointer (loaded from variable 'np') [clang-analyzer-core.NullDereference]
con_id = np->name;
^
drivers/pwm/core.c:1150:6: note: Assuming the condition is true
if (is_of_node(fwnode))
^~~~~~~~~~~~~~~~~~
drivers/pwm/core.c:1150:2: note: Taking true branch
if (is_of_node(fwnode))
^
drivers/pwm/core.c:1151:25: note: Assuming the condition is false
pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
^
include/linux/of.h:164:3: note: expanded from macro 'to_of_node'
is_of_node(__to_of_node_fwnode) ? \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/pwm/core.c:1151:25: note: '?' condition is false
pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
^
include/linux/of.h:164:3: note: expanded from macro 'to_of_node'
is_of_node(__to_of_node_fwnode) ? \
^
drivers/pwm/core.c:1151:25: note: Passing null pointer value via 2nd parameter 'np'
pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
^
include/linux/of.h:161:2: note: expanded from macro 'to_of_node'
({ \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/pwm/core.c:1151:9: note: Calling 'of_pwm_get'
pwm = of_pwm_get(dev, to_of_node(fwnode), con_id);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/pwm/core.c:775:6: note: Assuming 'con_id' is null
if (con_id) {
^~~~~~
drivers/pwm/core.c:775:2: note: Taking false branch
if (con_id) {
^
drivers/pwm/core.c:783:6: note: Assuming 'err' is 0
if (err) {
^~~
drivers/pwm/core.c:783:2: note: Taking false branch
if (err) {
^
drivers/pwm/core.c:788:25: note: Assuming '__of_fwnode_handle_node' is null
pc = fwnode_to_pwmchip(of_fwnode_handle(args.np));
^
include/linux/of.h:174:3: note: expanded from macro 'of_fwnode_handle'
__of_fwnode_handle_node ? \
^~~~~~~~~~~~~~~~~~~~~~~
drivers/pwm/core.c:788:25: note: '?' condition is false
pc = fwnode_to_pwmchip(of_fwnode_handle(args.np));
^
include/linux/of.h:174:3: note: expanded from macro 'of_fwnode_handle'
__of_fwnode_handle_node ? \
^
drivers/pwm/core.c:789:2: note: Taking false branch
if (IS_ERR(pc)) {
^
drivers/pwm/core.c:798:2: note: Taking false branch
if (IS_ERR(pwm))
^
drivers/pwm/core.c:802:2: note: Taking false branch
if (IS_ERR(dl)) {
^
drivers/pwm/core.c:814:7: note: 'con_id' is null
if (!con_id) {
^~~~~~
drivers/pwm/core.c:814:2: note: Taking true branch
if (!con_id) {
^
drivers/pwm/core.c:817:7: note: 'err' is < 0
if (err < 0)
^~~
drivers/pwm/core.c:817:3: note: Taking true branch
if (err < 0)
^
drivers/pwm/core.c:818:13: note: Access to field 'name' results in a dereference of a null pointer (loaded from variable 'np')
con_id = np->name;
^~
1 warning generated.
lib/crypto/chacha20poly1305-selftest.c:9027:7: warning: Value stored to 'total_len' is never read [clang-analyzer-deadcode.DeadStores]
for (total_len = POLY1305_DIGEST_SIZE; IS_ENABLED(DEBUG_CHACHA20POLY1305_SLOW_CHUNK_TEST)
^
lib/crypto/chacha20poly1305-selftest.c:9027:7: note: Value stored to 'total_len' is never read
6 warnings generated.
drivers/video/fbdev/udlfb.c:370:6: warning: Value stored to 'identical' during its initialization is never read [clang-analyzer-deadcode.DeadStores]
int identical = width;
^~~~~~~~~ ~~~~~
drivers/video/fbdev/udlfb.c:370:6: note: Value stored to 'identical' during its initialization is never read
int identical = width;
^~~~~~~~~ ~~~~~
drivers/video/fbdev/udlfb.c:564:3: warning: Value stored to 'back_start' is never read [clang-analyzer-deadcode.DeadStores]
back_start += offset;
^ ~~~~~~
drivers/video/fbdev/udlfb.c:564:3: note: Value stored to 'back_start' is never read

vim +23 drivers/gpio/gpio-virtio.c

22
> 23 struct virtio_gpio_line {
24 struct mutex lock; /* Protects line operation */
25 struct completion completion;
26 struct virtio_gpio_request req ____cacheline_aligned;
27 struct virtio_gpio_response res ____cacheline_aligned;
28 unsigned int rxlen;
29 };
30

--
0-DAY CI Kernel Test Service
https://01.org/lkp