From: kernel test robot <lkp@intel.com>
To: oe-kbuild@lists.linux.dev
Cc: lkp@intel.com
Subject: kernel/rseq.c:480:41: sparse: sparse: cast removes address space '__user' of expression
Date: Sun, 30 Aug 2026 14:24:50 +0800 [thread overview]
Message-ID: <202608301410.KXaPc9oO-lkp@intel.com> (raw)
::::::
:::::: Manual check reason: "bisect to a FBC not belonging to original linux-review patches: branch: linux-review/odion-efficios-com/rseq-uapi-add-rseq-operation-definitions/20260828-113339, commit: e8494bc5b81ab087f8fda3da91fb0349f6e08b83"
::::::
BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
TO: Olivier Dion <odion@efficios.com>
CC: 0day robot <lkp@intel.com>
tree: https://github.com/intel-lab-lkp/linux/commits/odion-efficios-com/rseq-uapi-add-rseq-operation-definitions/20260828-113339
head: 6442a4dd9f55ba8a0f39522b330200e1b8548bd5
commit: e8494bc5b81ab087f8fda3da91fb0349f6e08b83 rseq: register and unregister operations via prctl
date: 2 days ago
:::::: branch date: 2 days ago
:::::: commit date: 2 days ago
config: loongarch-randconfig-r131-20260829 (https://download.01.org/0day-ci/archive/20260830/202608301410.KXaPc9oO-lkp@intel.com/config)
compiler: clang version 24.0.0git (https://github.com/llvm/llvm-project 52774473867e49b5891ab9381accf4e5a3ce0024)
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260830/202608301410.KXaPc9oO-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202608301410.KXaPc9oO-lkp@intel.com/
sparse warnings: (new ones prefixed by >>)
>> kernel/rseq.c:480:41: sparse: sparse: cast removes address space '__user' of expression
vim +/__user +480 kernel/rseq.c
0f085b41880e314 Thomas Gleixner 2025-10-27 431
99428157dcf32fd Thomas Gleixner 2026-04-26 432 static long rseq_register(struct rseq __user * rseq, u32 rseq_len, int flags, u32 sig)
d7822b1e24f2df5 Mathieu Desnoyers 2018-06-02 433 {
d7a5da7a0f7fa7f Thomas Gleixner 2025-12-15 434 u32 rseqfl = 0;
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 435 u8 version = 1;
d7a5da7a0f7fa7f Thomas Gleixner 2025-12-15 436
96d4f267e40f950 Linus Torvalds 2019-01-03 437 if (!access_ok(rseq, rseq_len))
d7822b1e24f2df5 Mathieu Desnoyers 2018-06-02 438 return -EFAULT;
fd881d0a085fc54 Michael Jeanson 2025-03-06 439
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 440 /*
99428157dcf32fd Thomas Gleixner 2026-04-26 441 * Architectures, which use the generic IRQ entry code (at least) enable
99428157dcf32fd Thomas Gleixner 2026-04-26 442 * registrations with a size greater than the original v1 fixed sized
99428157dcf32fd Thomas Gleixner 2026-04-26 443 * @rseq_len, which has been validated already to utilize the optimized
99428157dcf32fd Thomas Gleixner 2026-04-26 444 * v2 ABI mode which also enables extended RSEQ features beyond MMCID.
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 445 */
99428157dcf32fd Thomas Gleixner 2026-04-26 446 if (IS_ENABLED(CONFIG_GENERIC_IRQ_ENTRY) && rseq_len > ORIG_RSEQ_SIZE)
99428157dcf32fd Thomas Gleixner 2026-04-26 447 version = 2;
99428157dcf32fd Thomas Gleixner 2026-04-26 448
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 449 if (IS_ENABLED(CONFIG_RSEQ_SLICE_EXTENSION) && version > 1) {
010b7723c0a3b9a Thomas Gleixner 2026-04-28 450 if (rseq_slice_extension_enabled()) {
d7a5da7a0f7fa7f Thomas Gleixner 2025-12-15 451 rseqfl |= RSEQ_CS_FLAG_SLICE_EXT_AVAILABLE;
010b7723c0a3b9a Thomas Gleixner 2026-04-28 452 if (flags & RSEQ_FLAG_SLICE_EXT_DEFAULT_ON)
d6200245c75e832 Peter Zijlstra 2026-01-19 453 rseqfl |= RSEQ_CS_FLAG_SLICE_EXT_ENABLED;
d6200245c75e832 Peter Zijlstra 2026-01-19 454 }
010b7723c0a3b9a Thomas Gleixner 2026-04-28 455 }
e8494bc5b81ab08 Olivier Dion 2026-08-28 456 if (version > 1)
e8494bc5b81ab08 Olivier Dion 2026-08-28 457 rseqfl |= RSEQ_CS_FLAG_RSEQ_OP_AVAILABLE;
d7a5da7a0f7fa7f Thomas Gleixner 2025-12-15 458
0f085b41880e314 Thomas Gleixner 2025-10-27 459 scoped_user_write_access(rseq, efault) {
fd881d0a085fc54 Michael Jeanson 2025-03-06 460 /*
fd881d0a085fc54 Michael Jeanson 2025-03-06 461 * If the rseq_cs pointer is non-NULL on registration, clear it to
fd881d0a085fc54 Michael Jeanson 2025-03-06 462 * avoid a potential segfault on return to user-space. The proper thing
fd881d0a085fc54 Michael Jeanson 2025-03-06 463 * to do would have been to fail the registration but this would break
fd881d0a085fc54 Michael Jeanson 2025-03-06 464 * older libcs that reuse the rseq area for new threads without
067b3b41b4dd5bf Thomas Gleixner 2025-10-27 465 * clearing the fields. Don't bother reading it, just reset it.
fd881d0a085fc54 Michael Jeanson 2025-03-06 466 */
0f085b41880e314 Thomas Gleixner 2025-10-27 467 unsafe_put_user(0UL, &rseq->rseq_cs, efault);
d7a5da7a0f7fa7f Thomas Gleixner 2025-12-15 468 unsafe_put_user(rseqfl, &rseq->flags, efault);
0f085b41880e314 Thomas Gleixner 2025-10-27 469 /* Initialize IDs in user space */
0f085b41880e314 Thomas Gleixner 2025-10-27 470 unsafe_put_user(RSEQ_CPU_ID_UNINITIALIZED, &rseq->cpu_id_start, efault);
0f085b41880e314 Thomas Gleixner 2025-10-27 471 unsafe_put_user(RSEQ_CPU_ID_UNINITIALIZED, &rseq->cpu_id, efault);
0f085b41880e314 Thomas Gleixner 2025-10-27 472 unsafe_put_user(0U, &rseq->node_id, efault);
0f085b41880e314 Thomas Gleixner 2025-10-27 473 unsafe_put_user(0U, &rseq->mm_cid, efault);
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 474
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 475 /*
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 476 * All fields past mm_cid are only valid for non-legacy v2
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 477 * registrations.
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 478 */
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 479 if (version > 1) {
e8494bc5b81ab08 Olivier Dion 2026-08-28 @480 u64 sentinel = (u64)&rseq->rseq_op_list;
e8494bc5b81ab08 Olivier Dion 2026-08-28 481
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 482 if (IS_ENABLED(CONFIG_RSEQ_SLICE_EXTENSION))
d7a5da7a0f7fa7f Thomas Gleixner 2025-12-15 483 unsafe_put_user(0U, &rseq->slice_ctrl.all, efault);
e8494bc5b81ab08 Olivier Dion 2026-08-28 484 /*
e8494bc5b81ab08 Olivier Dion 2026-08-28 485 * Initialize the rseq operation list sentinel as an
e8494bc5b81ab08 Olivier Dion 2026-08-28 486 * empty circular doubly-linked list pointing to itself.
e8494bc5b81ab08 Olivier Dion 2026-08-28 487 */
e8494bc5b81ab08 Olivier Dion 2026-08-28 488 unsafe_put_user(sentinel, &rseq->rseq_op_list.next, efault);
e8494bc5b81ab08 Olivier Dion 2026-08-28 489 unsafe_put_user(sentinel, &rseq->rseq_op_list.prev, efault);
0f085b41880e314 Thomas Gleixner 2025-10-27 490 }
b9eac6a9d93c952 Thomas Gleixner 2026-04-25 491 }
fd881d0a085fc54 Michael Jeanson 2025-03-06 492
dc0a241ceaf3b7d Michael Jeanson 2025-02-19 493 /*
dc0a241ceaf3b7d Michael Jeanson 2025-02-19 494 * Activate the registration by setting the rseq area address, length
dc0a241ceaf3b7d Michael Jeanson 2025-02-19 495 * and signature in the task struct.
dc0a241ceaf3b7d Michael Jeanson 2025-02-19 496 */
faba9d250eaec7a Thomas Gleixner 2025-10-27 497 current->rseq.usrptr = rseq;
faba9d250eaec7a Thomas Gleixner 2025-10-27 498 current->rseq.len = rseq_len;
faba9d250eaec7a Thomas Gleixner 2025-10-27 499 current->rseq.sig = sig;
dc0a241ceaf3b7d Michael Jeanson 2025-02-19 500
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
reply other threads:[~2026-08-30 6:25 UTC|newest]
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