On Thu, Apr 15, 2021 at 04:45:24PM -0700, Alexei Starovoitov wrote: > On Wed, Apr 14, 2021 at 12:52 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote: > > > > hi, > > while adding test for pinning the module while there's > > trampoline attach to it, I noticed that we don't allow > > link detach and following re-attach for trampolines. > > Adding that for tracing and lsm programs. > > > > You need to have patch [1] from bpf tree for test module > > attach test to pass. > > > > v5 changes: > > - fixed missing hlist_del_init change > > - fixed several ASSERT calls > > - added extra patch for missing ';' > > - added ASSERT macros to lsm test > > - added acks > > It doesn't work: hi, I got the same warning when running test without the patch [1] I mentioned: 861de02e5f3f bpf: Take module reference for trampoline in module I still don't see it in bpf-next/master jirka > [ 52.763254] ------------[ cut here ]------------ > [ 52.763767] WARNING: CPU: 2 PID: 1967 at kernel/bpf/syscall.c:2518 > bpf_tracing_link_release+0x34/0x40 > [ 52.764666] Modules linked in: bpf_preload [last unloaded: bpf_testmod] > [ 52.765310] CPU: 2 PID: 1967 Comm: test_progs Tainted: G > O 5.12.0-rc4-01652-gf03a9b92b5f3 #3293 > [ 52.766279] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > BIOS 1.11.0-2.el7 04/01/2014 > [ 52.767128] RIP: 0010:bpf_tracing_link_release+0x34/0x40 > [ 52.767653] Code: 8b 77 48 48 8b 7f 18 e8 ea 67 02 00 85 c0 75 1a > 48 8b 7b 48 e8 ad 60 02 00 48 8b 7b 50 48 85 ff 74 06 5b e9 6e ff ff > ff 5b c3 <0f> 0b eb e2 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 > fd 8b > [ 52.769444] RSP: 0018:ffffc900001bfe98 EFLAGS: 00010286 > [ 52.769957] RAX: 00000000ffffffed RBX: ffff88810218e420 RCX: 0000000000000000 > [ 52.770642] RDX: ffff888105e89f80 RSI: ffffffff8118e539 RDI: ffff88811cafec10 > [ 52.771338] RBP: ffff88810218e420 R08: 0000000000000270 R09: 00000000000003cb > [ 52.772041] R10: ffff8881002a1090 R11: ffff888237d2aaf0 R12: ffff888101951030 > [ 52.772729] R13: ffff888100226f20 R14: ffff88810629f180 R15: ffff888105e89f80 > [ 52.773419] FS: 00007f82c7b93700(0000) GS:ffff888237d00000(0000) > knlGS:0000000000000000 > [ 52.774213] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 52.774784] CR2: 00007f82c7ba1000 CR3: 0000000105cfc006 CR4: 00000000003706e0 > [ 52.775494] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 52.776199] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 52.776887] Call Trace: > [ 52.777143] bpf_link_free+0x25/0x40 > [ 52.777525] bpf_link_release+0x11/0x20 > [ 52.777924] __fput+0x9f/0x240 > [ 52.778234] task_work_run+0x63/0xb0 > [ 52.778588] exit_to_user_mode_prepare+0x132/0x140 > [ 52.779064] syscall_exit_to_user_mode+0x1d/0x40 > [ 52.779519] entry_SYSCALL_64_after_hwframe+0x44/0xae > [ 52.780026] RIP: 0033:0x7f82c6f3815d > [ 52.780384] Code: c2 20 00 00 75 10 b8 03 00 00 00 0f 05 48 3d 01 > f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 b8 03 00 00 > 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 37 fc ff ff 48 89 d0 48 83 c4 08 48 > 3d 01 > test_module_attach:FAIL:delete_module unexpected success: 0 > libbpf: prog 'handle_fexit': failed to attach: No such file or directory > test_module_attach:FAIL:attach_fexit unexpected error: -2 > #68 module_attach:FAIL > > and another in: > ./test_progs -t module > [ 156.660834] ------------[ cut here ]------------ > [ 156.661414] WARNING: CPU: 3 PID: 2511 at kernel/trace/ftrace.c:6321 > ftrace_module_enable+0x33a/0x370 > [ 156.662445] Modules linked in: bpf_testmod(O+) bpf_preload [last > unloaded: bpf_testmod] > [ 156.663325] CPU: 3 PID: 2511 Comm: test_progs Tainted: G W > O 5.12.0-rc4-01652-gf03a9b92b5f3 #3293 > [ 156.664369] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > BIOS 1.11.0-2.el7 04/01/2014 > [ 156.665265] RIP: 0010:ftrace_module_enable+0x33a/0x370 > [ 156.665890] Code: 00 00 74 9d 48 0d 00 00 00 10 48 89 45 08 e9 db > fe ff ff 8b 8b 98 01 00 00 48 01 ca 48 39 d0 0f 83 2c fd ff ff e9 66 > fd ff ff <0f> 0b e9 bd fe ff ff 0f 0b e9 b6 fe ff ff 48 83 78 10 00 0f > 85 dd > [ 156.667822] RSP: 0018:ffffc900001c7d50 EFLAGS: 00010206 > [ 156.668354] RAX: 0000000000000000 RBX: ffffffffa001c380 RCX: 0000000000005000 > [ 156.669079] RDX: 0000000000031045 RSI: ffffffffa0019080 RDI: 0000000000000000 > [ 156.669793] RBP: ffff888104bd9020 R08: ffffffff83174f00 R09: 0000000000000000 > [ 156.670529] R10: 0000000000000001 R11: ffffffffa0019080 R12: ffff88810092e480 > [ 156.671368] R13: 61c8864680b583eb R14: 0000000000000002 R15: 0000000000000000 > [ 156.672135] FS: 00007f198becc700(0000) GS:ffff888237d80000(0000) > knlGS:0000000000000000 > [ 156.672973] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 156.673625] CR2: 00000000006a14f0 CR3: 00000001169be003 CR4: 00000000003706e0 > [ 156.674411] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 156.675209] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 156.675959] Call Trace: > [ 156.676209] load_module+0x1f71/0x27d0 > [ 156.676623] ? __do_sys_finit_module+0x8f/0xc0 > [ 156.677084] __do_sys_finit_module+0x8f/0xc0 > [ 156.677525] do_syscall_64+0x2d/0x40 > [ 156.677932] entry_SYSCALL_64_after_hwframe+0x44/0xae > [ 156.678465] RIP: 0033:0x7f198afa37f9 > [ 156.678837] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 > 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 > 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 57 76 2b 00 f7 d8 64 89 > 01 48 > [ 156.680812] RSP: 002b:00007ffc428756d8 EFLAGS: 00000202 ORIG_RAX: > 0000000000000139 > [ 156.681614] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f198afa37f9 > [ 156.682344] RDX: 0000000000000000 RSI: 00000000006a14f7 RDI: 0000000000000004 > [ 156.683111] RBP: 00007ffc428758b8 R08: 00007f198becc700 R09: 00007ffc428758b8 > [ 156.683842] R10: 00007f198becc700 R11: 0000000000000202 R12: 000000000040bce0 > [ 156.684590] R13: 00007ffc428758b0 R14: 0000000000000000 R15: 0000000000000000 > [ 156.685335] ---[ end trace 7086b04742183c35 ]--- > #58 ksyms_module:OK >
