x86,kprobes: WARN if kprobes tries to handle a fault
With the removal of kprobe::handle_fault there is no reason left that
kprobe_page_fault() would ever return true on x86, make sure it
doesn't happen by accident.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210525073213.660594073@infradead.org
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 1c548ad..362255b 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1186,7 +1186,7 @@ do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code,
return;
/* kprobes don't want to hook the spurious faults: */
- if (kprobe_page_fault(regs, X86_TRAP_PF))
+ if (WARN_ON_ONCE(kprobe_page_fault(regs, X86_TRAP_PF)))
return;
/*
@@ -1239,7 +1239,7 @@ void do_user_addr_fault(struct pt_regs *regs,
}
/* kprobes don't want to hook the spurious faults: */
- if (unlikely(kprobe_page_fault(regs, X86_TRAP_PF)))
+ if (WARN_ON_ONCE(kprobe_page_fault(regs, X86_TRAP_PF)))
return;
/*