hi, I occasionally get following fault: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI CPU: 3 PID: 28438 Comm: test_progs Tainted: G OE 6.4.0-rc3+ #448 dad92bc91c459c664b308990ada0799837010e31 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc37 04/01/2014 RIP: 0010:rethook_try_get+0x34/0xf0 Code: 48 8b 47 08 85 d2 74 0b 65 8b 15 af 26 eb 7e 85 d2 74 57 48 85 c0 74 73 e8 39 8e f0 ff 84 c0 74 6a 48 8b 53 10 48 85 d2 74 > RSP: 0018:ffffc90003ccfcf0 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff88810920db40 RCX: 0000000000000003 RDX: 6b6b6b6b6b6b6b6b RSI: ffffffff82c0a371 RDI: ffffffff82bcbddb RBP: ffffffff81f5a5f0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000014000 R12: ffffffffa02ec3f2 R13: fffffffffffffff7 R14: ffffc90003ccfd38 R15: 0000000000000000 FS: 00007f2f8195eb80(0000) GS:ffff88846da00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f819c0140 CR3: 0000000189cb8006 CR4: 0000000000770ee0 PKRU: 55555554 Call Trace: <TASK> fprobe_handler+0xc1/0x270 ? __pfx_bpf_testmod_init+0x10/0x10 [bpf_testmod b0bc3019aa6d6bdb2afc30cf6381f510d7e5abbe] ? __pfx_bpf_testmod_init+0x10/0x10 [bpf_testmod b0bc3019aa6d6bdb2afc30cf6381f510d7e5abbe] ? bpf_fentry_test1+0x5/0x10 ? bpf_fentry_test1+0x5/0x10 ? bpf_testmod_init+0x22/0x80 [bpf_testmod b0bc3019aa6d6bdb2afc30cf6381f510d7e5abbe] ? do_one_initcall+0x63/0x2e0 ? rcu_is_watching+0xd/0x40 ? kmalloc_trace+0xaf/0xc0 ? do_init_module+0x60/0x250 ? __do_sys_finit_module+0xac/0x120 ? do_syscall_64+0x37/0x90 ? entry_SYSCALL_64_after_hwframe+0x72/0xdc </TASK> Modules linked in: bpf_testmod(OE+) loop bpf_preload intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul crc32c_intel > I can't really reliable reproduce this, but while checking the code, I wonder we should call rethook_free only after we call unregister_ftrace_function like in the patch below jirka --- diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index 18d36842faf5..0121e8c0d54e 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -364,19 +364,13 @@ int unregister_fprobe(struct fprobe *fp) fp->ops.saved_func != fprobe_kprobe_handler)) return -EINVAL; - /* - * rethook_free() starts disabling the rethook, but the rethook handlers - * may be running on other processors at this point. To make sure that all - * current running handlers are finished, call unregister_ftrace_function() - * after this. - */ - if (fp->rethook) - rethook_free(fp->rethook); - ret = unregister_ftrace_function(&fp->ops); if (ret < 0) return ret; + if (fp->rethook) + rethook_free(fp->rethook); + ftrace_free_filter(&fp->ops); return ret;
