Hi Masami, I love your patch! Perhaps something to improve: [auto build test WARNING on bpf/master] url: https://github.com/intel-lab-lkp/linux/commits/Masami-Hiramatsu/kprobes-rethook-ARM-arm64-Replace-kretprobe-trampoline-with-rethook/20220405-195153 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git master config: arm-randconfig-s032-20220406 (https://download.01.org/0day-ci/archive/20220407/202204070204.g3wpjuJi-lkp@xxxxxxxxx/config) compiler: arm-linux-gnueabi-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://github.com/intel-lab-lkp/linux/commit/99971b0c57ce1501eda858656ed06758bbd4e376 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Masami-Hiramatsu/kprobes-rethook-ARM-arm64-Replace-kretprobe-trampoline-with-rethook/20220405-195153 git checkout 99971b0c57ce1501eda858656ed06758bbd4e376 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=arm SHELL=/bin/bash arch/arm/kernel/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> sparse warnings: (new ones prefixed by >>) >> arch/arm/kernel/unwind.c:407:24: sparse: sparse: Using plain integer as NULL pointer vim +407 arch/arm/kernel/unwind.c 377 378 /* 379 * Unwind a single frame starting with *sp for the symbol at *pc. It 380 * updates the *pc and *sp with the new values. 381 */ 382 int unwind_frame(struct stackframe *frame) 383 { 384 const struct unwind_idx *idx; 385 struct unwind_ctrl_block ctrl; 386 unsigned long sp_low; 387 388 /* store the highest address on the stack to avoid crossing it*/ 389 sp_low = frame->sp; 390 ctrl.sp_high = ALIGN(sp_low - THREAD_SIZE, THREAD_ALIGN) 391 + THREAD_SIZE; 392 393 pr_debug("%s(pc = %08lx lr = %08lx sp = %08lx)\n", __func__, 394 frame->pc, frame->lr, frame->sp); 395 396 idx = unwind_find_idx(frame->pc); 397 if (!idx) { 398 if (frame->pc && kernel_text_address(frame->pc)) 399 pr_warn("unwind: Index not found %08lx\n", frame->pc); 400 return -URC_FAILURE; 401 } 402 403 ctrl.vrs[FP] = frame->fp; 404 ctrl.vrs[SP] = frame->sp; 405 ctrl.vrs[LR] = frame->lr; 406 ctrl.vrs[PC] = 0; > 407 ctrl.lr_addr = 0; 408 409 if (idx->insn == 1) 410 /* can't unwind */ 411 return -URC_FAILURE; 412 else if (frame->pc == prel31_to_addr(&idx->addr_offset)) { 413 /* 414 * Unwinding is tricky when we're halfway through the prologue, 415 * since the stack frame that the unwinder expects may not be 416 * fully set up yet. However, one thing we do know for sure is 417 * that if we are unwinding from the very first instruction of 418 * a function, we are still effectively in the stack frame of 419 * the caller, and the unwind info has no relevance yet. 420 */ 421 if (frame->pc == frame->lr) 422 return -URC_FAILURE; 423 frame->pc = frame->lr; 424 return URC_OK; 425 } else if ((idx->insn & 0x80000000) == 0) 426 /* prel31 to the unwind table */ 427 ctrl.insn = (unsigned long *)prel31_to_addr(&idx->insn); 428 else if ((idx->insn & 0xff000000) == 0x80000000) 429 /* only personality routine 0 supported in the index */ 430 ctrl.insn = &idx->insn; 431 else { 432 pr_warn("unwind: Unsupported personality routine %08lx in the index at %p\n", 433 idx->insn, idx); 434 return -URC_FAILURE; 435 } 436 437 /* check the personality routine */ 438 if ((*ctrl.insn & 0xff000000) == 0x80000000) { 439 ctrl.byte = 2; 440 ctrl.entries = 1; 441 } else if ((*ctrl.insn & 0xff000000) == 0x81000000) { 442 ctrl.byte = 1; 443 ctrl.entries = 1 + ((*ctrl.insn & 0x00ff0000) >> 16); 444 } else { 445 pr_warn("unwind: Unsupported personality routine %08lx at %p\n", 446 *ctrl.insn, ctrl.insn); 447 return -URC_FAILURE; 448 } 449 450 ctrl.check_each_pop = 0; 451 452 if (prel31_to_addr(&idx->addr_offset) == (u32)&call_with_stack) { 453 /* 454 * call_with_stack() is the only place where we permit SP to 455 * jump from one stack to another, and since we know it is 456 * guaranteed to happen, set up the SP bounds accordingly. 457 */ 458 sp_low = frame->fp; 459 ctrl.sp_high = ALIGN(frame->fp, THREAD_SIZE); 460 } 461 462 while (ctrl.entries > 0) { 463 int urc; 464 if ((ctrl.sp_high - ctrl.vrs[SP]) < sizeof(ctrl.vrs)) 465 ctrl.check_each_pop = 1; 466 urc = unwind_exec_insn(&ctrl); 467 if (urc < 0) 468 return urc; 469 if (ctrl.vrs[SP] < sp_low || ctrl.vrs[SP] > ctrl.sp_high) 470 return -URC_FAILURE; 471 } 472 473 if (ctrl.vrs[PC] == 0) 474 ctrl.vrs[PC] = ctrl.vrs[LR]; 475 476 /* check for infinite loop */ 477 if (frame->pc == ctrl.vrs[PC] && frame->sp == ctrl.vrs[SP]) 478 return -URC_FAILURE; 479 480 frame->fp = ctrl.vrs[FP]; 481 frame->sp = ctrl.vrs[SP]; 482 frame->lr = ctrl.vrs[LR]; 483 frame->pc = ctrl.vrs[PC]; 484 frame->lr_addr = ctrl.lr_addr; 485 486 return URC_OK; 487 } 488 -- 0-DAY CI Kernel Test Service https://01.org/lkp
