tree: https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git treewide/thread-flags head: d5fcb79b14c4566888a8a85004a261a740260a02 commit: db22de8cb00a64b2dc2d24bed04b8b0aef40b015 [9/11] powerpc: avoid discarding flags in system_call_exception() config: powerpc-randconfig-s031-20211118 (attached as .config) compiler: powerpc-linux-gcc (GCC) 11.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.4-dirty # https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/commit/?id... git remote add mark https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git git fetch --no-tags mark treewide/thread-flags git checkout db22de8cb00a64b2dc2d24bed04b8b0aef40b015 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) arch/powerpc/kernel/interrupt.c:151:64: sparse: expected unsigned long volatile *_p arch/powerpc/kernel/interrupt.c:151:64: sparse: got unsigned long flags vim +151 arch/powerpc/kernel/interrupt.c 76 77 /* Has to run notrace because it is entered not completely "reconciled" */ 78 notrace long system_call_exception(long r3, long r4, long r5, 79 long r6, long r7, long r8, 80 unsigned long r0, struct pt_regs *regs) 81 { 82 syscall_fn f; 83 84 kuep_lock(); 85 86 regs->orig_gpr3 = r3; 87 88 if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) 89 BUG_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED); 90 91 trace_hardirqs_off(); /* finish reconciling */ 92 93 CT_WARN_ON(ct_state() == CONTEXT_KERNEL); 94 user_exit_irqoff(); 95 96 BUG_ON(regs_is_unrecoverable(regs)); 97 BUG_ON(!(regs->msr & MSR_PR)); 98 BUG_ON(arch_irq_disabled_regs(regs)); 99 100 #ifdef CONFIG_PPC_PKEY 101 if (mmu_has_feature(MMU_FTR_PKEY)) { 102 unsigned long amr, iamr; 103 bool flush_needed = false; 104 /* 105 * When entering from userspace we mostly have the AMR/IAMR 106 * different from kernel default values. Hence don't compare. 107 */ 108 amr = mfspr(SPRN_AMR); 109 iamr = mfspr(SPRN_IAMR); 110 regs->amr = amr; 111 regs->iamr = iamr; 112 if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) { 113 mtspr(SPRN_AMR, AMR_KUAP_BLOCKED); 114 flush_needed = true; 115 } 116 if (mmu_has_feature(MMU_FTR_BOOK3S_KUEP)) { 117 mtspr(SPRN_IAMR, AMR_KUEP_BLOCKED); 118 flush_needed = true; 119 } 120 if (flush_needed) 121 isync(); 122 } else 123 #endif 124 kuap_assert_locked(); 125 126 booke_restore_dbcr0(); 127 128 account_cpu_user_entry(); 129 130 account_stolen_time(); 131 132 /* 133 * This is not required for the syscall exit path, but makes the 134 * stack frame look nicer. If this was initialised in the first stack 135 * frame, or if the unwinder was taught the first stack frame always 136 * returns to user with IRQS_ENABLED, this store could be avoided! 137 */ 138 irq_soft_mask_regs_set_state(regs, IRQS_ENABLED); 139 140 /* 141 * If system call is called with TM active, set _TIF_RESTOREALL to 142 * prevent RFSCV being used to return to userspace, because POWER9 143 * TM implementation has problems with this instruction returning to 144 * transactional state. Final register values are not relevant because 145 * the transaction will be aborted upon return anyway. Or in the case 146 * of unsupported_scv SIGILL fault, the return state does not much 147 * matter because it's an edge case. 148 */ 149 if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) && 150 unlikely(MSR_TM_TRANSACTIONAL(regs->msr))) 152 153 /* 154 * If the system call was made with a transaction active, doom it and 155 * return without performing the system call. Unless it was an 156 * unsupported scv vector, in which case it's treated like an illegal 157 * instruction. 158 */ 159 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 160 if (unlikely(MSR_TM_TRANSACTIONAL(regs->msr)) && 161 !trap_is_unsupported_scv(regs)) { 162 /* Enable TM in the kernel, and disable EE (for scv) */ 163 hard_irq_disable(); 164 mtmsr(mfmsr() | MSR_TM); 165 166 /* tabort, this dooms the transaction, nothing else */ 167 asm volatile(".long 0x7c00071d | ((%0) << 16)" 168 :: "r"(TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT)); 169 170 /* 171 * Userspace will never see the return value. Execution will 172 * resume after the tbegin. of the aborted transaction with the 173 * checkpointed register state. A context switch could occur 174 * or signal delivered to the process before resuming the 175 * doomed transaction context, but that should all be handled 176 * as expected. 177 */ 178 return -ENOSYS; 179 } 180 #endif // CONFIG_PPC_TRANSACTIONAL_MEM 181 182 local_irq_enable(); 183 184 if (unlikely(current_thread_info()->flags & _TIF_SYSCALL_DOTRACE)) { 185 if (unlikely(trap_is_unsupported_scv(regs))) { 186 /* Unsupported scv vector */ 187 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 188 return regs->gpr[3]; 189 } 190 /* 191 * We use the return value of do_syscall_trace_enter() as the 192 * syscall number. If the syscall was rejected for any reason 193 * do_syscall_trace_enter() returns an invalid syscall number 194 * and the test against NR_syscalls will fail and the return 195 * value to be used is in regs->gpr[3]. 196 */ 197 r0 = do_syscall_trace_enter(regs); 198 if (unlikely(r0 >= NR_syscalls)) 199 return regs->gpr[3]; 200 r3 = regs->gpr[3]; 201 r4 = regs->gpr[4]; 202 r5 = regs->gpr[5]; 203 r6 = regs->gpr[6]; 204 r7 = regs->gpr[7]; 205 r8 = regs->gpr[8]; 206 207 } else if (unlikely(r0 >= NR_syscalls)) { 208 if (unlikely(trap_is_unsupported_scv(regs))) { 209 /* Unsupported scv vector */ 210 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip); 211 return regs->gpr[3]; 212 } 213 return -ENOSYS; 214 } 215 216 /* May be faster to do array_index_nospec? */ 217 barrier_nospec(); 218 219 if (unlikely(is_compat_task())) { 220 f = (void *)compat_sys_call_table[r0]; 221 222 r3 &= 0x00000000ffffffffULL; 223 r4 &= 0x00000000ffffffffULL; 224 r5 &= 0x00000000ffffffffULL; 225 r6 &= 0x00000000ffffffffULL; 226 r7 &= 0x00000000ffffffffULL; 227 r8 &= 0x00000000ffffffffULL; 228 229 } else { 230 f = (void *)sys_call_table[r0]; 231 } 232 233 return f(r3, r4, r5, r6, r7, r8); 234 } 235 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org