From: Steven Rostedt <rostedt@goodmis.org>
To: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linux Trace Kernel <linux-trace-kernel@vger.kernel.org>,
Ye Bin <yebin@huaweicloud.com>, Naveen N Rao <naveen@kernel.org>,
"David S . Miller" <davem@davemloft.net>,
yebin10@huawei.com
Subject: Re: [PATCH] kprobes: avoid crash when rmmod/insmod after ftrace killed
Date: Wed, 3 Dec 2025 09:56:40 -0500 [thread overview]
Message-ID: <20251203095640.7a4fda6b@gandalf.local.home> (raw)
In-Reply-To: <176473947565.1727781.13110060700668331950.stgit@mhiramat.tok.corp.google.com>
On Wed, 3 Dec 2025 14:24:35 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> After we hit ftrace is killed by some errors, the kernel crash if
> we remove modules in which kprobe probes.
>
> BUG: unable to handle page fault for address: fffffbfff805000d
> PGD 817fcc067 P4D 817fcc067 PUD 817fc8067 PMD 101555067 PTE 0
> Oops: Oops: 0000 [#1] SMP KASAN PTI
> CPU: 4 UID: 0 PID: 2012 Comm: rmmod Tainted: G W OE
> Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
> RIP: 0010:kprobes_module_callback+0x89/0x790
> RSP: 0018:ffff88812e157d30 EFLAGS: 00010a02
> RAX: 1ffffffff805000d RBX: dffffc0000000000 RCX: ffffffff86a8de90
> RDX: ffffed1025c2af9b RSI: 0000000000000008 RDI: ffffffffc0280068
> RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1025c2af9a
> R10: ffff88812e157cd7 R11: 205d323130325420 R12: 0000000000000002
> R13: ffffffffc0290488 R14: 0000000000000002 R15: ffffffffc0280040
> FS: 00007fbc450dd740(0000) GS:ffff888420331000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: fffffbfff805000d CR3: 000000010f624000 CR4: 00000000000006f0
> Call Trace:
> <TASK>
> notifier_call_chain+0xc6/0x280
> blocking_notifier_call_chain+0x60/0x90
> __do_sys_delete_module.constprop.0+0x32a/0x4e0
> do_syscall_64+0x5d/0xfa0
> entry_SYSCALL_64_after_hwframe+0x76/0x7e
>
> This is because the kprobe on ftrace does not correctly handles
> the kprobe_ftrace_disabled flag set by ftrace_kill().
>
> To prevent this error, check kprobe_ftrace_disabled in
> __disarm_kprobe_ftrace() and skip all ftrace related operations.
>
> Reported-by: Ye Bin <yebin10@huawei.com>
> Closes: https://lore.kernel.org/all/20251125020536.2484381-1-yebin@huaweicloud.com/
> Fixes: ae6aa16fdc16 ("kprobes: introduce ftrace based optimization")
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-- Steve
prev parent reply other threads:[~2025-12-03 14:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-03 5:24 [PATCH] kprobes: avoid crash when rmmod/insmod after ftrace killed Masami Hiramatsu (Google)
2025-12-03 14:56 ` Steven Rostedt [this message]
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