On Tue, Apr 25, 2023 at 04:24:43PM -0600, Jim Cromie wrote: > If format changes are not /sys/** ABI violating, heres 3 minor ones: > > 1st strips "age <increasing>" from output. This makes the output > idempotent; unchanging until a new leak is reported. > > 2nd adds the backtrace.checksum to the "backtrace:" line. This lets a > user see repeats without actually reading the whole backtrace. So now > the backtrace line looks like this: > > backtrace (ck 603070071): # also see below > > Q: should ck be spelled crc ? it feels more communicative. These all would make sense (and 'crc' sounds better) if they were done from the start. I know there are test scripts out there parsing the kmemleak sysfs file. I can't tell whether these changes would break them. Cc'ing Dmitry, I think syzbot was regularly checking kmemleak (not sure it still does). > NB: with ck exposed, it becomes possible to do a "selective clear", > something like: > > echo drop 603070071 > /sys/kernel/debug/kmemleak > > The 3rd patch takes __init off of kmemleak_test_init(). This fixes a > bare-pointer in the 2nd line of the backtrace below, which previously > looked like: > > [<00000000ef738764>] 0xffffffffc02350a2 > > NB: this happens still/again, after rmmod kmemleak-test. > > unreferenced object 0xffff888005d9ca40 (size 32): > comm "modprobe", pid 412, jiffies 4294703300 > hex dump (first 32 bytes): > 00 cd d9 05 80 88 ff ff 40 cf d9 05 80 88 ff ff ........@....... > 14 a7 c4 f6 7d f9 87 10 00 00 00 00 00 00 00 00 ....}........... > backtrace (ck 1354775490): > [<000000002c474f61>] kmalloc_trace+0x26/0x90 > [<00000000b26599c1>] kmemleak_test_init+0x58/0x2d0 [kmemleak_test] > [<0000000044d13990>] do_one_initcall+0x43/0x210 > [<00000000131bc505>] do_init_module+0x4a/0x210 > [<00000000b2902890>] __do_sys_finit_module+0x93/0xf0 > [<00000000673fdce2>] do_syscall_64+0x34/0x80 > [<00000000357a2d80>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 -- Catalin
