:::::: :::::: Manual check reason: "low confidence static check warning: arch/x86/kernel/fpu/xstate.c:605:7: warning: Redundant initialization for 'size'. The initialized value is overwritten before it is read. [redundantInitialization]" ::::::
BCC: l...@intel.com CC: kbuild-...@lists.01.org CC: linux-ker...@vger.kernel.org TO: Thomas Gleixner <t...@linutronix.de> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: eb555cb5b794f4e12a9897f3d46d5a72104cd4a7 commit: 8ad7e8f696951f192c6629a0cbda9ac94c773159 x86/fpu/xsave: Support XSAVEC in the kernel date: 4 months ago :::::: branch date: 4 hours ago :::::: commit date: 4 months ago compiler: gcc-11 (Debian 11.3.0-3) 11.3.0 reproduce (cppcheck warning): # apt-get install cppcheck git checkout 8ad7e8f696951f192c6629a0cbda9ac94c773159 cppcheck --quiet --enable=style,performance,portability --template=gcc FILE If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <l...@intel.com> cppcheck warnings: (new ones prefixed by >>) arch/x86/kernel/fpu/xstate.c:1236:7: warning: Local variable 'mask' shadows outer variable [shadowVariable] u64 mask = ((u64)1 << i); ^ arch/x86/kernel/fpu/xstate.c:1205:6: note: Shadowed declaration u64 mask; ^ arch/x86/kernel/fpu/xstate.c:1236:7: note: Shadow variable u64 mask = ((u64)1 << i); ^ cppcheck possible warnings: (new ones prefixed by >>, may not real problems) >> arch/x86/kernel/fpu/xstate.c:605:7: warning: Redundant initialization for >> 'size'. The initialized value is overwritten before it is read. >> [redundantInitialization] size = xstate_calculate_size(fpu_kernel_cfg.max_features, compacted); ^ arch/x86/kernel/fpu/xstate.c:590:20: note: size is initialized unsigned int size = FXSAVE_SIZE + XSAVE_HDR_SIZE; ^ arch/x86/kernel/fpu/xstate.c:605:7: note: size is overwritten size = xstate_calculate_size(fpu_kernel_cfg.max_features, compacted); ^ >> arch/x86/kernel/fpu/xstate.c:589:7: warning: Local variable 'xsaves' shadows >> outer function [shadowFunction] bool xsaves = cpu_feature_enabled(X86_FEATURE_XSAVES); ^ arch/x86/kernel/fpu/xstate.c:1310:6: note: Shadowed declaration void xsaves(struct xregs_state *xstate, u64 mask) ^ arch/x86/kernel/fpu/xstate.c:589:7: note: Shadow variable bool xsaves = cpu_feature_enabled(X86_FEATURE_XSAVES); ^ arch/x86/kernel/fpu/xstate.c:1708:43: warning: Parameter 'tsk' can be declared with const [constParameter] long fpu_xstate_prctl(struct task_struct *tsk, int option, unsigned long arg2) ^ vim +/size +605 arch/x86/kernel/fpu/xstate.c 84e4dccc8fce20 Chang S. Bae 2021-10-21 576 65ac2e9baa7dee Dave Hansen 2015-09-02 577 /* 65ac2e9baa7dee Dave Hansen 2015-09-02 578 * This essentially double-checks what the cpu told us about 65ac2e9baa7dee Dave Hansen 2015-09-02 579 * how large the XSAVE buffer needs to be. We are recalculating 65ac2e9baa7dee Dave Hansen 2015-09-02 580 * it to be safe. 76d10256a97a7c Kan Liang 2020-07-20 581 * 01707b66535872 Andy Lutomirski 2021-06-23 582 * Independent XSAVE features allocate their own buffers and are not 76d10256a97a7c Kan Liang 2020-07-20 583 * covered by these checks. Only the size of the buffer for task->fpu 76d10256a97a7c Kan Liang 2020-07-20 584 * is checked here. 65ac2e9baa7dee Dave Hansen 2015-09-02 585 */ cd9ae761744912 Thomas Gleixner 2021-10-15 586 static bool __init paranoid_xstate_size_valid(unsigned int kernel_size) 65ac2e9baa7dee Dave Hansen 2015-09-02 587 { 8ad7e8f696951f Thomas Gleixner 2022-04-04 588 bool compacted = cpu_feature_enabled(X86_FEATURE_XCOMPACTED); 8ad7e8f696951f Thomas Gleixner 2022-04-04 @589 bool xsaves = cpu_feature_enabled(X86_FEATURE_XSAVES); cd9ae761744912 Thomas Gleixner 2021-10-15 590 unsigned int size = FXSAVE_SIZE + XSAVE_HDR_SIZE; 65ac2e9baa7dee Dave Hansen 2015-09-02 591 int i; 65ac2e9baa7dee Dave Hansen 2015-09-02 592 1c253ff2287fe3 Thomas Gleixner 2021-10-15 593 for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) { cd9ae761744912 Thomas Gleixner 2021-10-15 594 if (!check_xstate_against_struct(i)) cd9ae761744912 Thomas Gleixner 2021-10-15 595 return false; 65ac2e9baa7dee Dave Hansen 2015-09-02 596 /* 65ac2e9baa7dee Dave Hansen 2015-09-02 597 * Supervisor state components can be managed only by 02b93c0b00df22 Thomas Gleixner 2021-06-23 598 * XSAVES. 65ac2e9baa7dee Dave Hansen 2015-09-02 599 */ 8ad7e8f696951f Thomas Gleixner 2022-04-04 600 if (!xsaves && xfeature_is_supervisor(i)) { cd9ae761744912 Thomas Gleixner 2021-10-15 601 XSTATE_WARN_ON(1); cd9ae761744912 Thomas Gleixner 2021-10-15 602 return false; cd9ae761744912 Thomas Gleixner 2021-10-15 603 } 65ac2e9baa7dee Dave Hansen 2015-09-02 604 } 84e4dccc8fce20 Chang S. Bae 2021-10-21 @605 size = xstate_calculate_size(fpu_kernel_cfg.max_features, compacted); cd9ae761744912 Thomas Gleixner 2021-10-15 606 XSTATE_WARN_ON(size != kernel_size); cd9ae761744912 Thomas Gleixner 2021-10-15 607 return size == kernel_size; 65ac2e9baa7dee Dave Hansen 2015-09-02 608 } 65ac2e9baa7dee Dave Hansen 2015-09-02 609 :::::: The code at line 605 was first introduced by commit :::::: 84e4dccc8fce20b497388d756e12de5c9006eb48 x86/fpu/xstate: Provide xstate_calculate_size() :::::: TO: Chang S. Bae <chang.seok....@intel.com> :::::: CC: Borislav Petkov <b...@suse.de> -- 0-DAY CI Kernel Test Service https://01.org/lkp _______________________________________________ kbuild mailing list -- kbuild@lists.01.org To unsubscribe send an email to kbuild-le...@lists.01.org
