Commit:
0cb2f1372b ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler")
fixed one bug but the underlying bugs are not completely fixed yet.
If we run a kprobe_module.tc of ftracetest, a warning triggers:
# ./ftracetest test.d/kprobe/kprobe_module.tc
=== Ftrace unit tests ===
[1] Kprobe dynamic event - probing module
...
------------[ cut here ]------------
Failed to disarm kprobe-ftrace at trace_printk_irq_work+0x0/0x7e [trace_printk] (-2)
WARNING: CPU: 7 PID: 200 at kernel/kprobes.c:1091 __disarm_kprobe_ftrace.isra.0+0x7e/0xa0
This is because the kill_kprobe() calls disarm_kprobe_ftrace() even
if the given probe is not enabled. In that case, ftrace_set_filter_ip()
fails because the given probe point is not registered to ftrace.
Fix to check the given (going) probe is enabled before invoking
disarm_kprobe_ftrace().
Fixes: 0cb2f1372b ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/159888672694.1411785.5987998076694782591.stgit@devnote2
bcb53209be