From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0E7FE19C542; Sun, 22 Feb 2026 15:26:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771774001; cv=none; b=CHNcNOt5ITJDdT+QJCx8iVLYtOL47NM/9lMAVvENwYgBT/dB1vvXiDDXWQtppibxD5FADM2lZ2Z9MCQO2S8PeSL+EQT43SaB5qzkXXRnkReTrRlr3ijVzoV0FAa9fZahFxo1TuEcyF7iIUJBKQGdVXuqkqX9jqJnGlXwN/6VqJc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771774001; c=relaxed/simple; bh=WZHqKZ7RHO9FGDtLNE9eTusosEENC9JH1jqIRs2bwUo=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=LONvvea4HNGSS+31lPmT6rxMfNFKIuYAGgxogcLnuRzHiGLyOceYJ0+ukL2P5fti7KqyvmKucICGuyUnCwodxuIONCp4cYGpDJiOGFMn4F05w0VXrNSfg9+jVkOKetIys9INJwPbNsDkGtiRAITfXllyvCZDyU0E32SDgJj/2fs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FOAVHYQH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FOAVHYQH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47E07C116D0; Sun, 22 Feb 2026 15:26:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771774000; bh=WZHqKZ7RHO9FGDtLNE9eTusosEENC9JH1jqIRs2bwUo=; h=From:To:Cc:Subject:Date:From; b=FOAVHYQHYYkTdHL6rTzMh7gNolEM4asR6tPB1+GPgpGwXgq3xV8ygqv84cFa9H2Yi llwMs4XNGXby/j8qZdyBJXgfAs6V2139MYveFNo/KdE+YONLnR3+yLb4mtQJpHVJjN dWJmUKmwByXXRhcnz777ukC2X2dD49KG+nU8wRsYz1isW2/6gFsPRw8odcEkt1UfFU 2wEhTDUndD39ATIw+z94ggpyebC/eTX/4sBZEKCr436JMLPYUCmKzVh8zvOTZiynSV uGiKoZ36vFrty35QIh9/lno18wxd9ksvRUaV2AHEF/r0iPwLMG3jru+K+Gex7Gz2kx OGCQ1NLj2cmag== From: "Masami Hiramatsu (Google)" To: stable@vger.kernel.org, Steven Rostedt Cc: Mathieu Desnoyers , Masami Hiramatsu , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH 6.12.y] tracing: Fix to clear fprobe after unregister_fprobe() when module unloading Date: Mon, 23 Feb 2026 00:26:36 +0900 Message-ID: <177177399650.99709.12415733322341955461.stgit@devnote2> X-Mailer: git-send-email 2.43.0 User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu Clear fprobe after unregister_fprobe() for preventing double unregistering fprobe. Without this fix, test.d/dynevent/add_remove_tprobe_module.tc test case of ftracetest caused a kernel panic as below on 6.12.y. This is only happens on 6.12.y because this bug was introduced by commit 5ba4f58ec2de ("tracing: tprobe-events: Fix to clean up tprobe correctly when module unload"). This fix expects that the new fprobe implementation based on fgraph, but on 6.12.y, fprobe is still using ftrace. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 156 at kernel/trace/ftrace.c:378 __unregister_ftrace_function+0x154/0x170 Modules linked in: [last unloaded: trace_events_sample] CPU: 0 UID: 0 PID: 156 Comm: ftracetest Not tainted 6.12.74 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:__unregister_ftrace_function+0x154/0x170 Code: 85 30 ff ff ff c6 05 fd d5 85 01 01 48 c7 c7 eb 8e 14 82 be 39 01 00 00 48 c7 c2 dd bd 1c 82 e8 52 12 93 00 e9 0c ff ff ff 90 <0f> 0b 90 b8 f0 ff ff ff 5b e9 be 8b 95 00 cc 66 66 66 66 2e 0f 1f RSP: 0018:ffffc900005c3b48 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880054ba818 RCX: 7a7d3ccd1e752c00 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8880054ba818 RBP: 0000000000000000 R08: 000000000000017b R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: ffff8880048216d0 R13: ffff8880052f7850 R14: ffff8880054ba818 R15: ffffffff8124e160 FS: 000000002de743c0(0000) GS:ffff88807d800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002de8b898 CR3: 0000000005b3a000 CR4: 00000000000006b0 Call Trace: ftrace_shutdown+0x25/0x260 ? __pfx_dyn_event_open+0x10/0x10 unregister_ftrace_function+0x2a/0x140 ? __pfx_dyn_event_open+0x10/0x10 unregister_fprobe+0x57/0x90 trace_fprobe_release+0x56/0x150 dyn_event_open+0x99/0xe0 do_dentry_open+0x14a/0x3e0 vfs_open+0x2c/0xe0 path_openat+0xca5/0xf10 ? __lock_acquire+0xd38/0x2af0 ? __create_object+0x36/0x100 ? __create_object+0x36/0x100 do_filp_open+0xb5/0x160 do_sys_openat2+0x7f/0xd0 __x64_sys_openat+0x81/0xa0 do_syscall_64+0xec/0x1d0 ? exc_page_fault+0x92/0x110 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x4aa9cb Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14 25 RSP: 002b:00007ffce30daf50 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000002de79bd0 RCX: 00000000004aa9cb RDX: 0000000000000241 RSI: 000000002deb08f0 RDI: 00000000ffffff9c RBP: 000000002deb08f0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000241 R13: 000000002deb08f0 R14: 00007ffce30db3f8 R15: 0000000000000000 irq event stamp: 147361 hardirqs last enabled at (147373): [] __console_unlock+0x81/0xd0 hardirqs last disabled at (147386): [] __console_unlock+0x66/0xd0 softirqs last enabled at (146866): [] handle_softirqs+0x34f/0x3b0 softirqs last disabled at (146861): [] __irq_exit_rcu+0x66/0xd0 ---[ end trace 0000000000000000 ]--- BUG: kernel NULL pointer dereference, address: 000000000000002e #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 8000000005af0067 P4D 8000000005af0067 PUD 55d7067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 UID: 0 PID: 156 Comm: ftracetest Tainted: G W 6.12.74 #1 Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:trace_fprobe_release+0x78/0x150 Code: 4c 89 f7 e8 ba e2 ff ff ba f0 01 00 00 4c 89 f7 31 f6 e8 9b 64 8d 00 48 8b bb 10 02 00 00 48 85 ff 74 21 4c 8d b3 10 02 00 00 <48> 8b 77 30 31 d2 e8 8d cf f8 ff 49 c7 06 00 00 00 00 49 c7 46 08 RSP: 0018:ffffc900005c3be8 EFLAGS: 00010282 RAX: ffff8880054ba818 RBX: ffff8880054ba800 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: fffffffffffffffe RBP: 00000000fffffff0 R08: 000000000000017b R09: 0000000000000000 R10: ffff8880054ba818 R11: 0000000000000000 R12: ffff8880048216d0 R13: ffff8880052f7850 R14: ffff8880054baa10 R15: ffffffff8124e160 FS: 000000002de743c0(0000) GS:ffff88807d800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000002e CR3: 0000000005b3a000 CR4: 00000000000006b0 Call Trace: dyn_event_open+0x99/0xe0 do_dentry_open+0x14a/0x3e0 vfs_open+0x2c/0xe0 path_openat+0xca5/0xf10 ? __lock_acquire+0xd38/0x2af0 ? __create_object+0x36/0x100 ? __create_object+0x36/0x100 do_filp_open+0xb5/0x160 do_sys_openat2+0x7f/0xd0 __x64_sys_openat+0x81/0xa0 do_syscall_64+0xec/0x1d0 ? exc_page_fault+0x92/0x110 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x4aa9cb Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00 00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14 25 RSP: 002b:00007ffce30daf50 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000002de79bd0 RCX: 00000000004aa9cb RDX: 0000000000000241 RSI: 000000002deb08f0 RDI: 00000000ffffff9c RBP: 000000002deb08f0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000241 R13: 000000002deb08f0 R14: 00007ffce30db3f8 R15: 0000000000000000 Modules linked in: [last unloaded: trace_events_sample] CR2: 000000000000002e ---[ end trace 0000000000000000 ]--- Fixes: 5ba4f58ec2de ("tracing: tprobe-events: Fix to clean up tprobe correctly when module unload") Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_fprobe.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index 440dbfa6bbfd..2cf5036c825d 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -984,6 +984,7 @@ static int __tracepoint_probe_module_cb(struct notifier_block *self, } } else if (val == MODULE_STATE_GOING && tp_mod->mod == tf->mod) { unregister_fprobe(&tf->fp); + memset(&tf->fp, 0, sizeof(tf->fp)); if (trace_fprobe_is_tracepoint(tf)) { tracepoint_probe_unregister(tf->tpoint, tf->tpoint->probestub, NULL);