* drivers/hv/channel_mgmt.c:785:22: warning: Assigned value is garbage or undefined [clang-analyzer-core.uninitialized.Assign]
[not found] <202107251901.GJvlsBLV-lkp@intel.com>
@ 2021-07-26 3:43 ` kernel test robot
2021-07-26 16:02 ` Haiyang Zhang
0 siblings, 1 reply; 3+ messages in thread
From: kernel test robot @ 2021-07-26 3:43 UTC (permalink / raw)
To: Haiyang Zhang; +Cc: kbuild-all, LKML, Wei Liu, Michael Kelley
[-- Attachment #1: Type: text/plain, Size: 20550 bytes --]
Hi Haiyang,
First bad commit (maybe != root cause):
tree:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: d8079fac168168b25677dc16c00ffaf9fb7df723
commit: 7c9ff3deeee61b253715dcf968a6307af148c9b2 Drivers: hv: vmbus: Fix
duplicate CPU assignments within a device
date: 6 days ago
:::::: branch date: 11 hours ago
:::::: commit date: 6 days ago
config: x86_64-randconfig-c001-20210725 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project
3f2c1e99e44d028d5e9dd685f3c568f2661f2f68)
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 x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
#
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c9ff3deeee61b253715dcf968a6307af148c9b2
git remote add linus
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 7c9ff3deeee61b253715dcf968a6307af148c9b2
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross
clang-analyzer ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
clang-analyzer warnings: (new ones prefixed by >>)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hid/hid-core.c:1601:3: note: Taking false branch
if (field->logical_minimum < 0) /* signed values */
^
drivers/hid/hid-core.c:1605:44: note: Passing value via 4th
parameter 'n'
implement(hid, data, offset + n * size, size,
^~~~
drivers/hid/hid-core.c:1605:4: note: Calling 'implement'
implement(hid, data, offset + n * size, size,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hid/hid-core.c:1421:15: note: Assuming 'n' is <= 32
if (unlikely(n > 32)) {
^
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
drivers/hid/hid-core.c:1421:2: note: Taking false branch
if (unlikely(n > 32)) {
^
drivers/hid/hid-core.c:1425:13: note: Assuming 'n' is >= 32
} else if (n < 32) {
^~~~~~
drivers/hid/hid-core.c:1425:9: note: Taking false branch
} else if (n < 32) {
^
drivers/hid/hid-core.c:1437:30: note: Passing the value 32 via 3rd
parameter 'n'
__implement(report, offset, n, value);
^
drivers/hid/hid-core.c:1437:2: note: Calling '__implement'
__implement(report, offset, n, value);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hid/hid-core.c:1400:9: note: Assuming the condition is false
while (n - bits_to_set >= 0) {
^~~~~~~~~~~~~~~~~~~~
drivers/hid/hid-core.c:1400:2: note: Loop condition is false.
Execution continues on line 1411
while (n - bits_to_set >= 0) {
^
drivers/hid/hid-core.c:1411:6: note: 'n' is 32
if (n) {
^
drivers/hid/hid-core.c:1411:2: note: Taking true branch
if (n) {
^
drivers/hid/hid-core.c:1412:22: note: The result of the left shift
is undefined due to shifting by '32', which is greater or equal to the
width of type 'unsigned int'
u8 bit_mask = ((1U << n) - 1);
^ ~
drivers/hid/hid-core.c:1984:3: warning: Value stored to 'len' is
never read [clang-analyzer-deadcode.DeadStores]
len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hid/hid-core.c:1984:3: note: Value stored to 'len' is never read
len += sprintf(buf + len, "%shidraw%d", len ? "," : "",
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Suppressed 5 warnings (5 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.
Suppressed 6 warnings (6 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.
Suppressed 6 warnings (6 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.
7 warnings generated.
Suppressed 7 warnings (7 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.
Suppressed 5 warnings (5 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.
3 warnings generated.
Suppressed 3 warnings (3 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.
Suppressed 9 warnings (8 in non-user code, 1 with check filters).
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.
Suppressed 5 warnings (5 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/hv/channel_mgmt.c:785:22: warning: Assigned value is garbage or undefined [clang-analyzer-core.uninitialized.Assign]
channel->target_cpu = target_cpu;
^
drivers/hv/channel_mgmt.c:608:2: note: Left side of '&&' is false
list_for_each_entry(channel, &vmbus_connection.chn_list,
listentry) {
^
include/linux/list.h:628:13: note: expanded from macro
'list_for_each_entry'
for (pos = list_first_entry(head, typeof(*pos), member);
\
^
include/linux/list.h:522:2: note: expanded from macro 'list_first_entry'
list_entry((ptr)->next, type, member)
^
include/linux/list.h:511:2: note: expanded from macro 'list_entry'
container_of(ptr, type, member)
^
include/linux/kernel.h:495:61: note: expanded from macro 'container_of'
BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member)
&& \
^
drivers/hv/channel_mgmt.c:608:2: note: Taking false branch
list_for_each_entry(channel, &vmbus_connection.chn_list,
listentry) {
^
include/linux/list.h:628:13: note: expanded from macro
'list_for_each_entry'
for (pos = list_first_entry(head, typeof(*pos), member);
\
^
include/linux/list.h:522:2: note: expanded from macro 'list_first_entry'
list_entry((ptr)->next, type, member)
^
include/linux/list.h:511:2: note: expanded from macro 'list_entry'
container_of(ptr, type, member)
^
note: (skipping 2 expansions in backtrace; use
-fmacro-backtrace-limit=0 to see all)
include/linux/compiler_types.h:328:2: note: expanded from macro
'compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_,
__COUNTER__)
^
include/linux/compiler_types.h:316:2: note: expanded from macro
'_compiletime_assert'
__compiletime_assert(condition, msg, prefix, suffix)
^
include/linux/compiler_types.h:308:3: note: expanded from macro
'__compiletime_assert'
if (!(condition))
\
^
drivers/hv/channel_mgmt.c:608:2: note: Loop condition is false.
Exiting loop
list_for_each_entry(channel, &vmbus_connection.chn_list,
listentry) {
^
include/linux/list.h:628:13: note: expanded from macro
'list_for_each_entry'
for (pos = list_first_entry(head, typeof(*pos), member);
\
^
include/linux/list.h:522:2: note: expanded from macro 'list_first_entry'
list_entry((ptr)->next, type, member)
^
include/linux/list.h:511:2: note: expanded from macro 'list_entry'
container_of(ptr, type, member)
^
note: (skipping 2 expansions in backtrace; use
-fmacro-backtrace-limit=0 to see all)
include/linux/compiler_types.h:328:2: note: expanded from macro
'compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_,
__COUNTER__)
^
include/linux/compiler_types.h:316:2: note: expanded from macro
'_compiletime_assert'
__compiletime_assert(condition, msg, prefix, suffix)
^
include/linux/compiler_types.h:306:2: note: expanded from macro
'__compiletime_assert'
do {
\
^
drivers/hv/channel_mgmt.c:608:2: note: Loop condition is false.
Execution continues on line 619
list_for_each_entry(channel, &vmbus_connection.chn_list,
listentry) {
^
include/linux/list.h:628:2: note: expanded from macro
'list_for_each_entry'
for (pos = list_first_entry(head, typeof(*pos), member);
\
^
drivers/hv/channel_mgmt.c:619:2: note: Calling 'init_vp_index'
init_vp_index(newchannel);
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hv/channel_mgmt.c:732:2: note: 'target_cpu' declared without
an initial value
u32 target_cpu;
^~~~~~~~~~~~~~
drivers/hv/channel_mgmt.c:735:7: note: Assuming the condition is false
if ((vmbus_proto_version == VERSION_WS2008) ||
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hv/channel_mgmt.c:735:6: note: Left side of '||' is false
if ((vmbus_proto_version == VERSION_WS2008) ||
^
drivers/hv/channel_mgmt.c:736:7: note: Assuming the condition is false
(vmbus_proto_version == VERSION_WIN7) || (!perf_chn) ||
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hv/channel_mgmt.c:735:6: note: Left side of '||' is false
if ((vmbus_proto_version == VERSION_WS2008) ||
^
drivers/hv/channel_mgmt.c:736:48: note: Assuming 'perf_chn' is true
(vmbus_proto_version == VERSION_WIN7) || (!perf_chn) ||
^~~~~~~~~
drivers/hv/channel_mgmt.c:735:6: note: Left side of '||' is false
if ((vmbus_proto_version == VERSION_WS2008) ||
^
drivers/hv/channel_mgmt.c:737:7: note: Calling 'alloc_cpumask_var'
!alloc_cpumask_var(&available_mask, GFP_KERNEL)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/cpumask.h:740:2: note: Returning the value 1, which
participates in a condition later
return true;
^~~~~~~~~~~
drivers/hv/channel_mgmt.c:737:7: note: Returning from
'alloc_cpumask_var'
!alloc_cpumask_var(&available_mask, GFP_KERNEL)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
vim +785 drivers/hv/channel_mgmt.c
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 714 a119845f6e98c8
K. Y. Srinivasan 2012-12-01 715 /*
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 716 * Starting
with Win8, we can statically distribute the incoming
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 717 * channel
interrupt load by binding a channel to VCPU.
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 718 *
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 719 * For pre-win8
hosts or non-performance critical channels we assign the
d570aec0f2154e Andrea Parri (Microsoft 2020-04-06 720) *
VMBUS_CONNECT_CPU.
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 721) *
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 722) * Starting
with win8, performance critical channels will be distributed
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 723) * evenly among
all the available NUMA nodes. Once the node is assigned,
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 724) * we will
assign the CPU based on a simple round robin scheme.
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 725 */
afaa33da08abd1 Andrea Parri (Microsoft 2020-05-22 726) static void
init_vp_index(struct vmbus_channel *channel)
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 727 {
afaa33da08abd1 Andrea Parri (Microsoft 2020-05-22 728) bool perf_chn
= hv_is_perf_channel(channel);
7c9ff3deeee61b Haiyang Zhang 2021-07-16 729 u32 i, ncpu =
num_online_cpus();
25355252607ca2 Dexuan Cui 2018-09-23 730 cpumask_var_t
available_mask;
9f01ec53458d9e K. Y. Srinivasan 2015-08-05 731 struct cpumask
*alloced_mask;
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 732) u32 target_cpu;
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 733) int numa_node;
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 734 a119845f6e98c8
K. Y. Srinivasan 2012-12-01 735 if ((vmbus_proto_version ==
VERSION_WS2008) ||
25355252607ca2 Dexuan Cui 2018-09-23 736
(vmbus_proto_version == VERSION_WIN7) || (!perf_chn) ||
25355252607ca2 Dexuan Cui 2018-09-23 737
!alloc_cpumask_var(&available_mask, GFP_KERNEL)) {
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 738 /*
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 739 * Prior to
win8, all channel interrupts are
d570aec0f2154e Andrea Parri (Microsoft 2020-04-06 740) * delivered
on VMBUS_CONNECT_CPU.
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 741 * Also if
the channel is not a performance critical
d570aec0f2154e Andrea Parri (Microsoft 2020-04-06 742) * channel,
bind it to VMBUS_CONNECT_CPU.
d570aec0f2154e Andrea Parri (Microsoft 2020-04-06 743) * In case
alloc_cpumask_var() fails, bind it to
d570aec0f2154e Andrea Parri (Microsoft 2020-04-06 744) *
VMBUS_CONNECT_CPU.
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 745 */
d570aec0f2154e Andrea Parri (Microsoft 2020-04-06 746)
channel->target_cpu = VMBUS_CONNECT_CPU;
afaa33da08abd1 Andrea Parri (Microsoft 2020-05-22 747) if (perf_chn)
afaa33da08abd1 Andrea Parri (Microsoft 2020-05-22 748)
hv_set_alloced_cpu(VMBUS_CONNECT_CPU);
d3ba720dd58cdf K. Y. Srinivasan 2014-04-08 749 return;
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 750 }
ce59fec836a9b4 Vitaly Kuznetsov 2015-05-06 751 7c9ff3deeee61b
Haiyang Zhang 2021-07-16 752 for (i = 1; i <= ncpu + 1; i++) {
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 753 while (true) {
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 754) numa_node =
next_numa_node_id++;
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 755) if
(numa_node == nr_node_ids) {
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 756)
next_numa_node_id = 0;
509879bdb30b8e K. Y. Srinivasan 2016-09-02 757 continue;
509879bdb30b8e K. Y. Srinivasan 2016-09-02 758 }
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 759) if
(cpumask_empty(cpumask_of_node(numa_node)))
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 760 continue;
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 761 break;
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 762 }
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 763) alloced_mask
= &hv_context.hv_numa_map[numa_node];
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 764 9f01ec53458d9e
K. Y. Srinivasan 2015-08-05 765 if
(cpumask_weight(alloced_mask) ==
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 766)
cpumask_weight(cpumask_of_node(numa_node))) {
ce59fec836a9b4 Vitaly Kuznetsov 2015-05-06 767 /*
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 768 * We have
cycled through all the CPUs in the node;
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 769 * reset the
alloced map.
ce59fec836a9b4 Vitaly Kuznetsov 2015-05-06 770 */
9f01ec53458d9e K. Y. Srinivasan 2015-08-05 771
cpumask_clear(alloced_mask);
ce59fec836a9b4 Vitaly Kuznetsov 2015-05-06 772 }
ce59fec836a9b4 Vitaly Kuznetsov 2015-05-06 773 7c9ff3deeee61b
Haiyang Zhang 2021-07-16 774 cpumask_xor(available_mask,
alloced_mask,
7c9ff3deeee61b Haiyang Zhang 2021-07-16 775
cpumask_of_node(numa_node));
79fd8e706637a5 Vitaly Kuznetsov 2016-01-27 776 8ef4c4abbbcdcd
Andrea Parri (Microsoft 2020-04-06 777) target_cpu =
cpumask_first(available_mask);
8ef4c4abbbcdcd Andrea Parri (Microsoft 2020-04-06 778)
cpumask_set_cpu(target_cpu, alloced_mask);
1f656ff3fdddc2 K. Y. Srinivasan 2015-05-30 779 7c9ff3deeee61b
Haiyang Zhang 2021-07-16 780 if
(channel->offermsg.offer.sub_channel_index >= ncpu ||
7c9ff3deeee61b Haiyang Zhang 2021-07-16 781 i > ncpu
|| !hv_cpuself_used(target_cpu, channel))
7c9ff3deeee61b Haiyang Zhang 2021-07-16 782 break;
7c9ff3deeee61b Haiyang Zhang 2021-07-16 783 }
7c9ff3deeee61b Haiyang Zhang 2021-07-16 784 8ef4c4abbbcdcd
Andrea Parri (Microsoft 2020-04-06 @785) channel->target_cpu = target_cpu;
25355252607ca2 Dexuan Cui 2018-09-23 786 25355252607ca2
Dexuan Cui 2018-09-23 787 free_cpumask_var(available_mask);
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 788 }
a119845f6e98c8 K. Y. Srinivasan 2012-12-01 789
:::::: The code at line 785 was first introduced by commit
:::::: 8ef4c4abbbcdcd9d4bc0fd9454df03e6dac24b73 Drivers: hv: vmbus:
Remove the unused HV_LOCALIZED channel affinity logic
:::::: TO: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
:::::: CC: Wei Liu <wei.liu@kernel.org>
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 29581 bytes --]
[-- Attachment #3: Attached Message Part --]
[-- Type: text/plain, Size: 150 bytes --]
_______________________________________________
kbuild mailing list -- kbuild@lists.01.org
To unsubscribe send an email to kbuild-leave@lists.01.org
^ permalink raw reply [flat|nested] 3+ messages in thread
* RE: drivers/hv/channel_mgmt.c:785:22: warning: Assigned value is garbage or undefined [clang-analyzer-core.uninitialized.Assign]
2021-07-26 3:43 ` drivers/hv/channel_mgmt.c:785:22: warning: Assigned value is garbage or undefined [clang-analyzer-core.uninitialized.Assign] kernel test robot
@ 2021-07-26 16:02 ` Haiyang Zhang
2021-07-28 8:32 ` Chen, Rong A
0 siblings, 1 reply; 3+ messages in thread
From: Haiyang Zhang @ 2021-07-26 16:02 UTC (permalink / raw)
To: kernel test robot; +Cc: kbuild-all, LKML, Wei Liu, Michael Kelley
> -----Original Message-----
> From: kernel test robot <rong.a.chen@intel.com>
> Sent: Sunday, July 25, 2021 11:43 PM
> To: Haiyang Zhang <haiyangz@microsoft.com>
> Cc: kbuild-all@lists.01.org; LKML <linux-kernel@vger.kernel.org>; Wei
> Liu <wei.liu@kernel.org>; Michael Kelley <mikelley@microsoft.com>
> Subject: drivers/hv/channel_mgmt.c:785:22: warning: Assigned value is
> garbage or undefined [clang-analyzer-core.uninitialized.Assign]
>
>
> Hi Haiyang,
>
> First bad commit (maybe != root cause):
>
> tree:
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.ke
> rnel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git&d
> ata=04%7C01%7Chaiyangz%40microsoft.com%7Cb1a7f087851b48a29bf308d94fe7849
> 0%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637628680585035821%7CUnkn
> own%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLC
> JXVCI6Mn0%3D%7C1000&sdata=6LkKnX%2BXhjmhh4m%2BzJ7y0JeQcwvwHw8NZP%2Bv
> aXSdZV0%3D&reserved=0 master
> head: d8079fac168168b25677dc16c00ffaf9fb7df723
> commit: 7c9ff3deeee61b253715dcf968a6307af148c9b2 Drivers: hv: vmbus: Fix
> duplicate CPU assignments within a device
> date: 6 days ago
> :::::: branch date: 11 hours ago
> :::::: commit date: 6 days ago
> config: x86_64-randconfig-c001-20210725 (attached as .config)
> compiler: clang version 13.0.0
> (https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithu
> b.com%2Fllvm%2Fllvm-
> project&data=04%7C01%7Chaiyangz%40microsoft.com%7Cb1a7f087851b48a29b
> f308d94fe78490%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637628680585
> 035821%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBT
> iI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=MKdTDUGKunqVOWEwafejDKuW0mpeN
> aP1ssqiv4SBvzQ%3D&reserved=0
> 3f2c1e99e44d028d5e9dd685f3c568f2661f2f68)
> reproduce (this is a W=1 build):
> wget
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fraw.gi
> thubusercontent.com%2Fintel%2Flkp-
> tests%2Fmaster%2Fsbin%2Fmake.cross&data=04%7C01%7Chaiyangz%40microso
> ft.com%7Cb1a7f087851b48a29bf308d94fe78490%7C72f988bf86f141af91ab2d7cd011
> db47%7C1%7C0%7C637628680585035821%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLj
> AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=gu
> Hq8MagK88xMw%2F6ZxmhQExnmLoIlYLma4QR1gmUYdM%3D&reserved=0
> -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # install x86_64 cross compiling tool for clang build
> # apt-get install binutils-x86-64-linux-gnu
> #
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.ke
> rnel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%2Fcom
> mit%2F%3Fid%3D7c9ff3deeee61b253715dcf968a6307af148c9b2&data=04%7C01%
> 7Chaiyangz%40microsoft.com%7Cb1a7f087851b48a29bf308d94fe78490%7C72f988bf
> 86f141af91ab2d7cd011db47%7C1%7C0%7C637628680585035821%7CUnknown%7CTWFpbG
> Zsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D
> %7C1000&sdata=N24YX%2FPLzONY5gKOu1U93%2B7uK4jm%2BIQYZzfA6z8FPHo%3D&a
> mp;reserved=0
> git remote add linus
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.ke
> rnel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git&d
> ata=04%7C01%7Chaiyangz%40microsoft.com%7Cb1a7f087851b48a29bf308d94fe7849
> 0%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637628680585035821%7CUnkn
> own%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLC
> JXVCI6Mn0%3D%7C1000&sdata=6LkKnX%2BXhjmhh4m%2BzJ7y0JeQcwvwHw8NZP%2Bv
> aXSdZV0%3D&reserved=0
> git fetch --no-tags linus master
> git checkout 7c9ff3deeee61b253715dcf968a6307af148c9b2
> # save the attached .config to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross
> clang-analyzer ARCH=x86_64 If you fix the issue, kindly add following
> tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
>
> clang-analyzer warnings: (new ones prefixed by >>)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/hid/hid-core.c:1601:3: note: Taking false branch
> if (field->logical_minimum < 0) /* signed values */
> ^
> drivers/hid/hid-core.c:1605:44: note: Passing value via 4th
> parameter 'n'
> implement(hid, data, offset + n * size, size,
> ^~~~
> drivers/hid/hid-core.c:1605:4: note: Calling 'implement'
> implement(hid, data, offset + n * size, size,
>
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/hid/hid-core.c:1421:15: note: Assuming 'n' is <= 32
> if (unlikely(n > 32)) {
> ^
> include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
> # define unlikely(x) __builtin_expect(!!(x), 0)
> ^
> drivers/hid/hid-core.c:1421:2: note: Taking false branch
> if (unlikely(n > 32)) {
> ^
> drivers/hid/hid-core.c:1425:13: note: Assuming 'n' is >= 32
> } else if (n < 32) {
> ^~~~~~
> drivers/hid/hid-core.c:1425:9: note: Taking false branch
> } else if (n < 32) {
> ^
> drivers/hid/hid-core.c:1437:30: note: Passing the value 32 via 3rd
> parameter 'n'
> __implement(report, offset, n, value);
> ^
> drivers/hid/hid-core.c:1437:2: note: Calling '__implement'
> __implement(report, offset, n, value);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/hid/hid-core.c:1400:9: note: Assuming the condition is false
> while (n - bits_to_set >= 0) {
> ^~~~~~~~~~~~~~~~~~~~
> drivers/hid/hid-core.c:1400:2: note: Loop condition is false.
> Execution continues on line 1411
> while (n - bits_to_set >= 0) {
> ^
> drivers/hid/hid-core.c:1411:6: note: 'n' is 32
> if (n) {
> ^
> drivers/hid/hid-core.c:1411:2: note: Taking true branch
> if (n) {
> ^
> drivers/hid/hid-core.c:1412:22: note: The result of the left shift
> is undefined due to shifting by '32', which is greater or equal to the
> width of type 'unsigned int'
> u8 bit_mask = ((1U << n) - 1);
> ^ ~
> drivers/hid/hid-core.c:1984:3: warning: Value stored to 'len' is
> never read [clang-analyzer-deadcode.DeadStores]
> len += sprintf(buf + len, "%shidraw%d", len ? "," :
> "",
> ^
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/hid/hid-core.c:1984:3: note: Value stored to 'len' is never
> read
> len += sprintf(buf + len, "%shidraw%d", len ? "," :
> "",
> ^
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Suppressed 5 warnings (5 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.
> Suppressed 6 warnings (6 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.
> Suppressed 6 warnings (6 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.
> 7 warnings generated.
> Suppressed 7 warnings (7 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.
> Suppressed 5 warnings (5 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.
> 3 warnings generated.
> Suppressed 3 warnings (3 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.
> Suppressed 9 warnings (8 in non-user code, 1 with check filters).
> 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.
> Suppressed 5 warnings (5 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/hv/channel_mgmt.c:785:22: warning: Assigned value is garbage
> >> or undefined [clang-analyzer-core.uninitialized.Assign]
> channel->target_cpu = target_cpu;
> ^
The for-loop before the assignment is always executed,
because ncpu = num_online_cpus() > 0:
for (i = 1; i <= ncpu + 1; i++) {
So the variable is assigned before Line 785:
target_cpu = cpumask_first(available_mask);
And, the following code ensures the available_mask is not empty:
if (cpumask_weight(alloced_mask) ==
cpumask_weight(cpumask_of_node(numa_node))) {
/*
* We have cycled through all the CPUs in the node;
* reset the alloced map.
*/
cpumask_clear(alloced_mask);
}
So the robot warning above can be ignored.
Thanks,
- Haiyang
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: drivers/hv/channel_mgmt.c:785:22: warning: Assigned value is garbage or undefined [clang-analyzer-core.uninitialized.Assign]
2021-07-26 16:02 ` Haiyang Zhang
@ 2021-07-28 8:32 ` Chen, Rong A
0 siblings, 0 replies; 3+ messages in thread
From: Chen, Rong A @ 2021-07-28 8:32 UTC (permalink / raw)
To: Haiyang Zhang; +Cc: kbuild-all, LKML, Wei Liu, Michael Kelley
On 7/27/2021 12:02 AM, Haiyang Zhang wrote:
>
>
>> -----Original Message-----
>> From: kernel test robot <rong.a.chen@intel.com>
>> Sent: Sunday, July 25, 2021 11:43 PM
>> To: Haiyang Zhang <haiyangz@microsoft.com>
>> Cc: kbuild-all@lists.01.org; LKML <linux-kernel@vger.kernel.org>; Wei
>> Liu <wei.liu@kernel.org>; Michael Kelley <mikelley@microsoft.com>
>> Subject: drivers/hv/channel_mgmt.c:785:22: warning: Assigned value is
>> garbage or undefined [clang-analyzer-core.uninitialized.Assign]
>>
>>
>> Hi Haiyang,
>>
>> First bad commit (maybe != root cause):
>>
>> tree:
>> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.ke
>> rnel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git&d
>> ata=04%7C01%7Chaiyangz%40microsoft.com%7Cb1a7f087851b48a29bf308d94fe7849
>> 0%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637628680585035821%7CUnkn
>> own%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLC
>> JXVCI6Mn0%3D%7C1000&sdata=6LkKnX%2BXhjmhh4m%2BzJ7y0JeQcwvwHw8NZP%2Bv
>> aXSdZV0%3D&reserved=0 master
>> head: d8079fac168168b25677dc16c00ffaf9fb7df723
>> commit: 7c9ff3deeee61b253715dcf968a6307af148c9b2 Drivers: hv: vmbus: Fix
>> duplicate CPU assignments within a device
>> date: 6 days ago
>> :::::: branch date: 11 hours ago
>> :::::: commit date: 6 days ago
>> config: x86_64-randconfig-c001-20210725 (attached as .config)
>> compiler: clang version 13.0.0
>> (https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithu
>> b.com%2Fllvm%2Fllvm-
>> project&data=04%7C01%7Chaiyangz%40microsoft.com%7Cb1a7f087851b48a29b
>> f308d94fe78490%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637628680585
>> 035821%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBT
>> iI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=MKdTDUGKunqVOWEwafejDKuW0mpeN
>> aP1ssqiv4SBvzQ%3D&reserved=0
>> 3f2c1e99e44d028d5e9dd685f3c568f2661f2f68)
>> reproduce (this is a W=1 build):
>> wget
>> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fraw.gi
>> thubusercontent.com%2Fintel%2Flkp-
>> tests%2Fmaster%2Fsbin%2Fmake.cross&data=04%7C01%7Chaiyangz%40microso
>> ft.com%7Cb1a7f087851b48a29bf308d94fe78490%7C72f988bf86f141af91ab2d7cd011
>> db47%7C1%7C0%7C637628680585035821%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLj
>> AwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=gu
>> Hq8MagK88xMw%2F6ZxmhQExnmLoIlYLma4QR1gmUYdM%3D&reserved=0
>> -O ~/bin/make.cross
>> chmod +x ~/bin/make.cross
>> # install x86_64 cross compiling tool for clang build
>> # apt-get install binutils-x86-64-linux-gnu
>> #
>> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.ke
>> rnel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git%2Fcom
>> mit%2F%3Fid%3D7c9ff3deeee61b253715dcf968a6307af148c9b2&data=04%7C01%
>> 7Chaiyangz%40microsoft.com%7Cb1a7f087851b48a29bf308d94fe78490%7C72f988bf
>> 86f141af91ab2d7cd011db47%7C1%7C0%7C637628680585035821%7CUnknown%7CTWFpbG
>> Zsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D
>> %7C1000&sdata=N24YX%2FPLzONY5gKOu1U93%2B7uK4jm%2BIQYZzfA6z8FPHo%3D&a
>> mp;reserved=0
>> git remote add linus
>> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.ke
>> rnel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Ftorvalds%2Flinux.git&d
>> ata=04%7C01%7Chaiyangz%40microsoft.com%7Cb1a7f087851b48a29bf308d94fe7849
>> 0%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637628680585035821%7CUnkn
>> own%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLC
>> JXVCI6Mn0%3D%7C1000&sdata=6LkKnX%2BXhjmhh4m%2BzJ7y0JeQcwvwHw8NZP%2Bv
>> aXSdZV0%3D&reserved=0
>> git fetch --no-tags linus master
>> git checkout 7c9ff3deeee61b253715dcf968a6307af148c9b2
>> # save the attached .config to linux build tree
>> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross
>> clang-analyzer ARCH=x86_64 If you fix the issue, kindly add following
>> tag as appropriate
>> Reported-by: kernel test robot <lkp@intel.com>
>>
>>
>> clang-analyzer warnings: (new ones prefixed by >>)
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/hid/hid-core.c:1601:3: note: Taking false branch
>> if (field->logical_minimum < 0) /* signed values */
>> ^
>> drivers/hid/hid-core.c:1605:44: note: Passing value via 4th
>> parameter 'n'
>> implement(hid, data, offset + n * size, size,
>> ^~~~
>> drivers/hid/hid-core.c:1605:4: note: Calling 'implement'
>> implement(hid, data, offset + n * size, size,
>>
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/hid/hid-core.c:1421:15: note: Assuming 'n' is <= 32
>> if (unlikely(n > 32)) {
>> ^
>> include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
>> # define unlikely(x) __builtin_expect(!!(x), 0)
>> ^
>> drivers/hid/hid-core.c:1421:2: note: Taking false branch
>> if (unlikely(n > 32)) {
>> ^
>> drivers/hid/hid-core.c:1425:13: note: Assuming 'n' is >= 32
>> } else if (n < 32) {
>> ^~~~~~
>> drivers/hid/hid-core.c:1425:9: note: Taking false branch
>> } else if (n < 32) {
>> ^
>> drivers/hid/hid-core.c:1437:30: note: Passing the value 32 via 3rd
>> parameter 'n'
>> __implement(report, offset, n, value);
>> ^
>> drivers/hid/hid-core.c:1437:2: note: Calling '__implement'
>> __implement(report, offset, n, value);
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/hid/hid-core.c:1400:9: note: Assuming the condition is false
>> while (n - bits_to_set >= 0) {
>> ^~~~~~~~~~~~~~~~~~~~
>> drivers/hid/hid-core.c:1400:2: note: Loop condition is false.
>> Execution continues on line 1411
>> while (n - bits_to_set >= 0) {
>> ^
>> drivers/hid/hid-core.c:1411:6: note: 'n' is 32
>> if (n) {
>> ^
>> drivers/hid/hid-core.c:1411:2: note: Taking true branch
>> if (n) {
>> ^
>> drivers/hid/hid-core.c:1412:22: note: The result of the left shift
>> is undefined due to shifting by '32', which is greater or equal to the
>> width of type 'unsigned int'
>> u8 bit_mask = ((1U << n) - 1);
>> ^ ~
>> drivers/hid/hid-core.c:1984:3: warning: Value stored to 'len' is
>> never read [clang-analyzer-deadcode.DeadStores]
>> len += sprintf(buf + len, "%shidraw%d", len ? "," :
>> "",
>> ^
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/hid/hid-core.c:1984:3: note: Value stored to 'len' is never
>> read
>> len += sprintf(buf + len, "%shidraw%d", len ? "," :
>> "",
>> ^
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> Suppressed 5 warnings (5 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.
>> Suppressed 6 warnings (6 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.
>> Suppressed 6 warnings (6 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.
>> 7 warnings generated.
>> Suppressed 7 warnings (7 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.
>> Suppressed 5 warnings (5 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.
>> 3 warnings generated.
>> Suppressed 3 warnings (3 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.
>> Suppressed 9 warnings (8 in non-user code, 1 with check filters).
>> 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.
>> Suppressed 5 warnings (5 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/hv/channel_mgmt.c:785:22: warning: Assigned value is garbage
>>>> or undefined [clang-analyzer-core.uninitialized.Assign]
>> channel->target_cpu = target_cpu;
>> ^
>
> The for-loop before the assignment is always executed,
> because ncpu = num_online_cpus() > 0:
> for (i = 1; i <= ncpu + 1; i++) {
>
> So the variable is assigned before Line 785:
> target_cpu = cpumask_first(available_mask);
>
> And, the following code ensures the available_mask is not empty:
> if (cpumask_weight(alloced_mask) ==
> cpumask_weight(cpumask_of_node(numa_node))) {
> /*
> * We have cycled through all the CPUs in the node;
> * reset the alloced map.
> */
> cpumask_clear(alloced_mask);
> }
>
> So the robot warning above can be ignored.
Thanks for the detailed explanation, please just ignore it.
Best Regards,
Rong Chen
>
> Thanks,
> - Haiyang
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-07-28 8:32 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <202107251901.GJvlsBLV-lkp@intel.com>
2021-07-26 3:43 ` drivers/hv/channel_mgmt.c:785:22: warning: Assigned value is garbage or undefined [clang-analyzer-core.uninitialized.Assign] kernel test robot
2021-07-26 16:02 ` Haiyang Zhang
2021-07-28 8:32 ` Chen, Rong A
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