diff options
| author | Rui Qi <qirui.001@bytedance.com> | 2026-08-07 19:24:33 -0600 |
|---|---|---|
| committer | Paul Walmsley <pjw@kernel.org> | 2026-08-07 19:24:33 -0600 |
| commit | e7d8ea6c6d1bc685a8943ffad2d3679be92d164f (patch) | |
| tree | b89a0f819f57fbfef538202895eefa2da79d6360 | |
| parent | 76555252981eefa209ba2a16544c4f1704ca330b (diff) | |
riscv: kprobes: Prevent probes in breakpoint handlers
The ftrace selftest multiple_kprobes.tc registers kprobe events on
the first 256 text symbols from /proc/kallsyms. If handle_break() is
selected as a probe target on RISC-V, the breakpoint exception path
can trap again before it reaches the kprobe breakpoint handler. That
recursively enters do_trap_break() and can make the system
unresponsive.
Mark handle_break() and its local probe dispatch helpers as nokprobe
symbols so they are added to the kprobe blacklist, matching other
low-level breakpoint exception paths.
Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://patch.msgid.link/20260806043807.2583001-1-qirui.001@bytedance.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
| -rw-r--r-- | arch/riscv/kernel/traps.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 8c62c771a656..f459f0c8aad2 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -270,6 +270,7 @@ static bool probe_single_step_handler(struct pt_regs *regs) return user ? uprobe_single_step_handler(regs) : kprobe_single_step_handler(regs); } +NOKPROBE_SYMBOL(probe_single_step_handler); static bool probe_breakpoint_handler(struct pt_regs *regs) { @@ -277,6 +278,7 @@ static bool probe_breakpoint_handler(struct pt_regs *regs) return user ? uprobe_breakpoint_handler(regs) : kprobe_breakpoint_handler(regs); } +NOKPROBE_SYMBOL(probe_breakpoint_handler); void handle_break(struct pt_regs *regs) { @@ -301,6 +303,7 @@ void handle_break(struct pt_regs *regs) else die(regs, "Kernel BUG"); } +NOKPROBE_SYMBOL(handle_break); asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs) { |