On Wed, 3 Dec 2025 14:24:35 +0900 "Masami Hiramatsu (Google)" <[email protected]> wrote:
> From: Masami Hiramatsu (Google) <[email protected]> > > 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 <[email protected]> > Closes: > https://lore.kernel.org/all/[email protected]/ > Fixes: ae6aa16fdc16 ("kprobes: introduce ftrace based optimization") > Signed-off-by: Masami Hiramatsu (Google) <[email protected]> Acked-by: Steven Rostedt (Google) <[email protected]> -- Steve
