Prohibit probing on IRQ handlers in irqentry_text because if it interrupts user mode, at that point we haven't changed to kernel space yet and which eventually leads a double fault. E.g.
# echo p apic_timer_interrupt > kprobe_events # echo 1 > events/kprobes/enable PANIC: double fault, error_code: 0x0 CPU: 1 PID: 814 Comm: less Not tainted 4.20.0-rc3+ #30 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:error_entry+0x12/0xf0 [snip] Call Trace: <ENTRY_TRAMPOLINE> ? native_iret+0x7/0x7 ? async_page_fault+0x8/0x30 ? trace_hardirqs_on_thunk+0x1c/0x1c ? error_entry+0x7c/0xf0 ? async_page_fault+0x8/0x30 ? native_iret+0x7/0x7 ? int3+0xa/0x20 ? trace_hardirqs_on_thunk+0x1c/0x1c ? error_entry+0x7c/0xf0 ? int3+0xa/0x20 ? apic_timer_interrupt+0x1/0x20 </ENTRY_TRAMPOLINE> Kernel panic - not syncing: Machine halted. Kernel Offset: disabled ---[ end Kernel panic - not syncing: Machine halted. ]---
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org --- arch/x86/kernel/kprobes/core.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index f4b954ff5b89..fed46ddb1eef 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1072,6 +1072,13 @@ NOKPROBE_SYMBOL(kprobe_fault_handler);
int __init arch_populate_kprobe_blacklist(void) { + int ret; + + ret = kprobe_add_area_blacklist((unsigned long)__irqentry_text_start, + (unsigned long)__irqentry_text_end); + if (ret) + return ret; + return kprobe_add_area_blacklist((unsigned long)__entry_text_start, (unsigned long)__entry_text_end); }