powerpc: Use kprobe blacklist for exception handlers
Currently we mark the C implementations of some exception handlers as
__kprobes. This has the effect of putting them in the ".kprobes.text"
section, which separates them from the rest of the text.
Instead we can use the blacklist macros to add the symbols to a
blacklist which kprobes will check. This allows the linker to move
exception handler functions close to callers and avoids trampolines in
larger kernels.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Reword change log a bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index bb1ffc5..d0b137d 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -205,7 +205,7 @@
* The return value is 0 if the fault was handled, or the signal
* number if this is a kernel fault that can't be handled here.
*/
-int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
+int do_page_fault(struct pt_regs *regs, unsigned long address,
unsigned long error_code)
{
enum ctx_state prev_state = exception_enter();
@@ -498,8 +498,8 @@
bail:
exception_exit(prev_state);
return rc;
-
}
+NOKPROBE_SYMBOL(do_page_fault);
/*
* bad_page_fault is called when we have a bad access from the kernel.