On Sat, 15 Jan 2022 12:58:46 +0800 kernel test robot wrote: > Hi Masami, > > I love your patch! Perhaps something to improve: > > [auto build test WARNING on stable/linux-5.4.y] > > url: https://github.com/0day-ci/linux/commits/Masami-Hiramatsu/Revert-ia64-kprobes-Use-generic-kretprobe-trampoline-handler/20220114-182111 > base: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-5.4.y > config: ia64-allmodconfig (https://download.01.org/0day-ci/archive/20220115/202201151231.g2sW8oWt-lkp@intel.com/config) > compiler: ia64-linux-gcc (GCC) 11.2.0 > 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://github.com/0day-ci/linux/commit/514059de80b018e0edcf434519ff6bf41b4a519b > git remote add linux-review https://github.com/0day-ci/linux > git fetch --no-tags linux-review Masami-Hiramatsu/Revert-ia64-kprobes-Use-generic-kretprobe-trampoline-handler/20220114-182111 > git checkout 514059de80b018e0edcf434519ff6bf41b4a519b > # save the config file to linux build tree > mkdir build_dir > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=ia64 SHELL=/bin/bash > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot > > All warnings (new ones prefixed by >>): > > arch/ia64/kernel/kprobes.c: In function 'get_kprobe_inst': > arch/ia64/kernel/kprobes.c:325:22: warning: variable 'template' set but not used [-Wunused-but-set-variable] > 325 | unsigned int template; > | ^~~~~~~~ This one is fixed by recent patch. https://lore.kernel.org/all/164208575387.1590449.8278421820882450166.stgit@devnote2/T/#u > arch/ia64/kernel/kprobes.c: At top level: > arch/ia64/kernel/kprobes.c:407:15: warning: no previous prototype for 'trampoline_probe_handler' [-Wmissing-prototypes] > 407 | int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) > | ^~~~~~~~~~~~~~~~~~~~~~~~ > arch/ia64/kernel/kprobes.c: In function 'trampoline_probe_handler': > >> arch/ia64/kernel/kprobes.c:414:17: warning: initialization of 'long unsigned int' from 'void *' makes integer from pointer without a cast [-Wint-conversion] > 414 | dereference_function_descriptor(kretprobe_trampoline); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Oops. I forgot to cast it. I'll resend the patch. Thank you, > > Kconfig warnings: (for reference only) > WARNING: unmet direct dependencies detected for FRAME_POINTER > Depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS > Selected by > - FAULT_INJECTION_STACKTRACE_FILTER && FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT && !X86_64 && !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 > > > vim +414 arch/ia64/kernel/kprobes.c > > 320 > 321 static void __kprobes get_kprobe_inst(bundle_t *bundle, uint slot, > 322 unsigned long *kprobe_inst, uint *major_opcode) > 323 { > 324 unsigned long kprobe_inst_p0, kprobe_inst_p1; > > 325 unsigned int template; > 326 > 327 template = bundle->quad0.template; > 328 > 329 switch (slot) { > 330 case 0: > 331 *major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT); > 332 *kprobe_inst = bundle->quad0.slot0; > 333 break; > 334 case 1: > 335 *major_opcode = (bundle->quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT); > 336 kprobe_inst_p0 = bundle->quad0.slot1_p0; > 337 kprobe_inst_p1 = bundle->quad1.slot1_p1; > 338 *kprobe_inst = kprobe_inst_p0 | (kprobe_inst_p1 << (64-46)); > 339 break; > 340 case 2: > 341 *major_opcode = (bundle->quad1.slot2 >> SLOT2_OPCODE_SHIFT); > 342 *kprobe_inst = bundle->quad1.slot2; > 343 break; > 344 } > 345 } > 346 > 347 /* Returns non-zero if the addr is in the Interrupt Vector Table */ > 348 static int __kprobes in_ivt_functions(unsigned long addr) > 349 { > 350 return (addr >= (unsigned long)__start_ivt_text > 351 && addr < (unsigned long)__end_ivt_text); > 352 } > 353 > 354 static int __kprobes valid_kprobe_addr(int template, int slot, > 355 unsigned long addr) > 356 { > 357 if ((slot > 2) || ((bundle_encoding[template][1] == L) && slot > 1)) { > 358 printk(KERN_WARNING "Attempting to insert unaligned kprobe " > 359 "at 0x%lx\n", addr); > 360 return -EINVAL; > 361 } > 362 > 363 if (in_ivt_functions(addr)) { > 364 printk(KERN_WARNING "Kprobes can't be inserted inside " > 365 "IVT functions at 0x%lx\n", addr); > 366 return -EINVAL; > 367 } > 368 > 369 return 0; > 370 } > 371 > 372 static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) > 373 { > 374 unsigned int i; > 375 i = atomic_add_return(1, &kcb->prev_kprobe_index); > 376 kcb->prev_kprobe[i-1].kp = kprobe_running(); > 377 kcb->prev_kprobe[i-1].status = kcb->kprobe_status; > 378 } > 379 > 380 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) > 381 { > 382 unsigned int i; > 383 i = atomic_read(&kcb->prev_kprobe_index); > 384 __this_cpu_write(current_kprobe, kcb->prev_kprobe[i-1].kp); > 385 kcb->kprobe_status = kcb->prev_kprobe[i-1].status; > 386 atomic_sub(1, &kcb->prev_kprobe_index); > 387 } > 388 > 389 static void __kprobes set_current_kprobe(struct kprobe *p, > 390 struct kprobe_ctlblk *kcb) > 391 { > 392 __this_cpu_write(current_kprobe, p); > 393 } > 394 > 395 static void kretprobe_trampoline(void) > 396 { > 397 } > 398 > 399 /* > 400 * At this point the target function has been tricked into > 401 * returning into our trampoline. Lookup the associated instance > 402 * and then: > 403 * - call the handler function > 404 * - cleanup by marking the instance as unused > 405 * - long jump back to the original return address > 406 */ > 407 int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) > 408 { > 409 struct kretprobe_instance *ri = NULL; > 410 struct hlist_head *head, empty_rp; > 411 struct hlist_node *tmp; > 412 unsigned long flags, orig_ret_address = 0; > 413 unsigned long trampoline_address = > > 414 dereference_function_descriptor(kretprobe_trampoline); > 415 > 416 INIT_HLIST_HEAD(&empty_rp); > 417 kretprobe_hash_lock(current, &head, &flags); > 418 > 419 /* > 420 * It is possible to have multiple instances associated with a given > 421 * task either because an multiple functions in the call path > 422 * have a return probe installed on them, and/or more than one return > 423 * return probe was registered for a target function. > 424 * > 425 * We can handle this because: > 426 * - instances are always inserted at the head of the list > 427 * - when multiple return probes are registered for the same > 428 * function, the first instance's ret_addr will point to the > 429 * real return address, and all the rest will point to > 430 * kretprobe_trampoline > 431 */ > 432 hlist_for_each_entry_safe(ri, tmp, head, hlist) { > 433 if (ri->task != current) > 434 /* another task is sharing our hash bucket */ > 435 continue; > 436 > 437 orig_ret_address = (unsigned long)ri->ret_addr; > 438 if (orig_ret_address != trampoline_address) > 439 /* > 440 * This is the real return address. Any other > 441 * instances associated with this task are for > 442 * other calls deeper on the call stack > 443 */ > 444 break; > 445 } > 446 > 447 regs->cr_iip = orig_ret_address; > 448 > 449 hlist_for_each_entry_safe(ri, tmp, head, hlist) { > 450 if (ri->task != current) > 451 /* another task is sharing our hash bucket */ > 452 continue; > 453 > 454 if (ri->rp && ri->rp->handler) > 455 ri->rp->handler(ri, regs); > 456 > 457 orig_ret_address = (unsigned long)ri->ret_addr; > 458 recycle_rp_inst(ri, &empty_rp); > 459 > 460 if (orig_ret_address != trampoline_address) > 461 /* > 462 * This is the real return address. Any other > 463 * instances associated with this task are for > 464 * other calls deeper on the call stack > 465 */ > 466 break; > 467 } > 468 kretprobe_assert(ri, orig_ret_address, trampoline_address); > 469 > 470 kretprobe_hash_unlock(current, &flags); > 471 > 472 hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { > 473 hlist_del(&ri->hlist); > 474 kfree(ri); > 475 } > 476 /* > 477 * By returning a non-zero value, we are telling > 478 * kprobe_handler() that we don't want the post_handler > 479 * to run (and have re-enabled preemption) > 480 */ > 481 return 1; > 482 } > 483 > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org -- Masami Hiramatsu