CC: llvm(a)lists.linux.dev CC: kbuild-all(a)lists.01.org CC: linux-kernel(a)vger.kernel.org TO: Peter Zijlstra <peterz(a)infradead.org&gt; CC: Valentin Schneider <valentin.schneider(a)arm.com&gt; CC: Daniel Bristot de Oliveira <bristot(a)redhat.com&gt; tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 0513e464f9007b70b96740271a948ca5ab6e7dd7 commit: 565790d28b1e33ee2f77bad5348b99f6dfc366fd sched: Fix balance_callback() date: 11 months ago :::::: branch date: 19 hours ago :::::: commit date: 11 months ago config: x86_64-randconfig-c007-20210927 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project dc6e8dfdfe7efecfda318d43a06fae18b40eb498) 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 # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 565790d28b1e33ee2f77bad5348b99f6dfc366fd # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 clang-analyzer If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; clang-analyzer warnings: (new ones prefixed by >>) ^ crypto/skcipher.c:359:11: note: Calling 'skcipher_walk_done' return skcipher_walk_done(walk, -EINVAL); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ crypto/skcipher.c:109:6: note: Assuming 'n' is not equal to 0 if (!n) ^~ crypto/skcipher.c:109:2: note: Taking false branch if (!n) ^ crypto/skcipher.c:112:2: note: Taking false branch if (likely(err >= 0)) { ^ crypto/skcipher.c:117:13: 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:117:2: note: Taking false branch if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS | ^ crypto/skcipher.c:123:13: note: Assuming the condition is false } else if (walk->flags & SKCIPHER_WALK_DIFF) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ crypto/skcipher.c:123:9: note: Taking false branch } else if (walk->flags & SKCIPHER_WALK_DIFF) { ^ crypto/skcipher.c:126:13: note: Assuming the condition is true } else if (walk->flags & SKCIPHER_WALK_COPY) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ crypto/skcipher.c:126:9: note: Taking true branch } else if (walk->flags & SKCIPHER_WALK_COPY) { ^ crypto/skcipher.c:127:3: note: Calling 'skcipher_map_dst' skcipher_map_dst(walk); ^~~~~~~~~~~~~~~~~~~~~~ crypto/skcipher.c:66:1: note: Returning without writing to 'walk->page' } ^ crypto/skcipher.c:127:3: note: Returning from 'skcipher_map_dst' skcipher_map_dst(walk); ^~~~~~~~~~~~~~~~~~~~~~ crypto/skcipher.c:128:3: note: Null pointer passed as 2nd argument to memory copy function memcpy(walk->dst.virt.addr, walk->page, n); ^ ~~~~~~~~~~ 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. fs/hfsplus/xattr_security.c:52:3: warning: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 [clang-analyzer-security.insecureAPI.strcpy] strcpy(xattr_name, XATTR_SECURITY_PREFIX); ^~~~~~ fs/hfsplus/xattr_security.c:52:3: note: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 strcpy(xattr_name, XATTR_SECURITY_PREFIX); ^~~~~~ fs/hfsplus/xattr_security.c:53:3: warning: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 [clang-analyzer-security.insecureAPI.strcpy] strcpy(xattr_name + ^~~~~~ fs/hfsplus/xattr_security.c:53:3: note: Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119 strcpy(xattr_name + ^~~~~~ Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 4 warnings generated. crypto/algboss.c:196:6: warning: Value stored to 'type' during its initialization is never read [clang-analyzer-deadcode.DeadStores] u32 type = param->type; ^~~~ ~~~~~~~~~~~ crypto/algboss.c:196:6: note: Value stored to 'type' during its initialization is never read u32 type = param->type; ^~~~ ~~~~~~~~~~~ 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. 2 warnings generated. Suppressed 2 warnings (2 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. 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. 2 warnings generated. Suppressed 2 warnings (2 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. 14 warnings generated. rq = finish_task_switch(prev); ^ ~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:3736:2: note: Value stored to 'rq' is never read rq = finish_task_switch(prev); ^ ~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:4269:16: warning: Value stored to 'preempt_disable_ip' during its initialization is never read [clang-analyzer-deadcode.DeadStores] unsigned long preempt_disable_ip = get_preempt_disable_ip(current); ^~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:4269:16: note: Value stored to 'preempt_disable_ip' during its initialization is never read unsigned long preempt_disable_ip = get_preempt_disable_ip(current); ^~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:4549:3: warning: Value stored to 'rq' is never read [clang-analyzer-deadcode.DeadStores] rq = context_switch(rq, prev, next, &rf); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:4549:3: note: Value stored to 'rq' is never read rq = context_switch(rq, prev, next, &rf); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:7128:3: warning: Value stored to 'ptr' is never read [clang-analyzer-deadcode.DeadStores] ptr += nr_cpu_ids * sizeof(void **); ^ kernel/sched/core.c:7128:3: note: Value stored to 'ptr' is never read kernel/sched/core.c:7309:2: warning: Value stored to 'preempt_disable_ip' is never read [clang-analyzer-deadcode.DeadStores] preempt_disable_ip = get_preempt_disable_ip(current); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c:7309:2: note: Value stored to 'preempt_disable_ip' is never read preempt_disable_ip = get_preempt_disable_ip(current); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Suppressed 9 warnings (5 in non-user code, 4 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. 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. 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 2 warnings generated. Suppressed 2 warnings (2 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. 13 warnings generated. mm/debug_vm_pgtable.c:80:8: warning: Value stored to 'pte' during its initialization is never read [clang-analyzer-deadcode.DeadStores] pte_t pte = pfn_pte(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:80:8: note: Value stored to 'pte' during its initialization is never read pte_t pte = pfn_pte(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:121:8: warning: Value stored to 'pte' during its initialization is never read [clang-analyzer-deadcode.DeadStores] pte_t pte = pfn_pte(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:121:8: note: Value stored to 'pte' during its initialization is never read pte_t pte = pfn_pte(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:159:8: warning: Value stored to 'pmd' during its initialization is never read [clang-analyzer-deadcode.DeadStores] pmd_t pmd = pfn_pmd(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:159:8: note: Value stored to 'pmd' during its initialization is never read pmd_t pmd = pfn_pmd(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:201:2: warning: Value stored to 'pgtable' is never read [clang-analyzer-deadcode.DeadStores] pgtable = pgtable_trans_huge_withdraw(mm, pmdp); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:201:2: note: Value stored to 'pgtable' is never read pgtable = pgtable_trans_huge_withdraw(mm, pmdp); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:241:8: warning: Value stored to 'pmd' during its initialization is never read [clang-analyzer-deadcode.DeadStores] pmd_t pmd = pfn_pmd(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:241:8: note: Value stored to 'pmd' during its initialization is never read pmd_t pmd = pfn_pmd(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:599:8: warning: Value stored to 'pte' during its initialization is never read [clang-analyzer-deadcode.DeadStores] pte_t pte = pfn_pte(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:599:8: note: Value stored to 'pte' during its initialization is never read pte_t pte = pfn_pte(pfn, prot); ^~~ ~~~~~~~~~~~~~~~~~~ mm/debug_vm_pgtable.c:612:8: warning: Value stored to 'pmd' during its initialization is never read [clang-analyzer-deadcode.DeadStores] vim +/rq +3736 kernel/sched/core.c ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3717 ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3718 /** ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3719 * schedule_tail - first thing a freshly forked thread must call. ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3720 * @prev: the thread we just switched away from. ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3721 */ 722a9f9299ca72 kernel/sched/core.c Andi Kleen 2014-05-02 3722 asmlinkage __visible void schedule_tail(struct task_struct *prev) ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3723 __releases(rq->lock) ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3724 { 1a43a14a5bd9c3 kernel/sched/core.c Oleg Nesterov 2014-10-08 3725 struct rq *rq; da19ab510343c6 kernel/sched.c Steven Rostedt 2009-07-29 3726 609ca066386b2e kernel/sched/core.c Peter Zijlstra 2015-09-28 3727 /* 609ca066386b2e kernel/sched/core.c Peter Zijlstra 2015-09-28 3728 * New tasks start with FORK_PREEMPT_COUNT, see there and 609ca066386b2e kernel/sched/core.c Peter Zijlstra 2015-09-28 3729 * finish_task_switch() for details. 609ca066386b2e kernel/sched/core.c Peter Zijlstra 2015-09-28 3730 * 609ca066386b2e kernel/sched/core.c Peter Zijlstra 2015-09-28 3731 * finish_task_switch() will drop rq->lock() and lower preempt_count 609ca066386b2e kernel/sched/core.c Peter Zijlstra 2015-09-28 3732 * and the preempt_enable() will end up enabling preemption (on 609ca066386b2e kernel/sched/core.c Peter Zijlstra 2015-09-28 3733 * PREEMPT_COUNT kernels). 609ca066386b2e kernel/sched/core.c Peter Zijlstra 2015-09-28 3734 */ 609ca066386b2e kernel/sched/core.c Peter Zijlstra 2015-09-28 3735 dfa50b605c2a93 kernel/sched/core.c Oleg Nesterov 2014-10-09 @3736 rq = finish_task_switch(prev); 1a43a14a5bd9c3 kernel/sched/core.c Oleg Nesterov 2014-10-08 3737 preempt_enable(); 70b97a7f0b19cf kernel/sched.c Ingo Molnar 2006-07-03 3738 ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3739 if (current->set_child_tid) b488893a390edf kernel/sched.c Pavel Emelyanov 2007-10-18 3740 put_user(task_pid_vnr(current), current->set_child_tid); 088fe47ce95254 kernel/sched/core.c Eric W. Biederman 2018-07-23 3741 088fe47ce95254 kernel/sched/core.c Eric W. Biederman 2018-07-23 3742 calculate_sigpending(); ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3743 } ^1da177e4c3f41 kernel/sched.c Linus Torvalds 2005-04-16 3744 :::::: The code at line 3736 was first introduced by commit :::::: dfa50b605c2a933b7bb1c1d575a0da4e897e3c7d sched: Make finish_task_switch() return 'struct rq *' :::::: TO: Oleg Nesterov <oleg(a)redhat.com&gt; :::::: CC: Ingo Molnar <mingo(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org