On Tue, Feb 11, 2020 at 11:24:05AM -0500, Qian Cai wrote: > The value of object->pointer could be accessed concurrently as noticed > by KCSAN, > > BUG: KCSAN: data-race in crc32_le_base / do_raw_spin_lock > > write to 0xffffb0ea683a7d50 of 4 bytes by task 23575 on cpu 12: > do_raw_spin_lock+0x114/0x200 > debug_spin_lock_after at kernel/locking/spinlock_debug.c:91 > (inlined by) do_raw_spin_lock at kernel/locking/spinlock_debug.c:115 > _raw_spin_lock+0x40/0x50 > __handle_mm_fault+0xa9e/0xd00 > handle_mm_fault+0xfc/0x2f0 > do_page_fault+0x263/0x6f9 > page_fault+0x34/0x40 > > read to 0xffffb0ea683a7d50 of 4 bytes by task 839 on cpu 60: > crc32_le_base+0x67/0x350 > crc32_le_base+0x67/0x350: > crc32_body at lib/crc32.c:106 > (inlined by) crc32_le_generic at lib/crc32.c:179 > (inlined by) crc32_le at lib/crc32.c:197 > kmemleak_scan+0x528/0xd90 > update_checksum at mm/kmemleak.c:1172 > (inlined by) kmemleak_scan at mm/kmemleak.c:1497 > kmemleak_scan_thread+0xcc/0xfa > kthread+0x1e0/0x200 > ret_from_fork+0x27/0x50 > > Reported by Kernel Concurrency Sanitizer on: > CPU: 60 PID: 839 Comm: kmemleak Tainted: G W L 5.5.0-next-20200210+ #3 > Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 > > crc32() will dereference object->pointer. If a shattered value was > returned due to a data race, it will be corrected in the next scan. > Thus, annotate it as an intentional data race using the data_race() > macro. > > Signed-off-by: Qian Cai <cai@xxxxxx> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
