Re: [RFC PATCH 4/4] powerpc: mm/slb: blacklist symbols from kprobe

On 2016/11/18 08:36PM, Michael Ellerman wrote:

"Naveen N. Rao" [off-list ref] writes:

quoted

We can't really take a trap at this point. So, blacklist these symbols.

Reported-by: Anton Blanchard <redacted>
Signed-off-by: Naveen N. Rao <redacted>
---
 arch/powerpc/mm/slb_low.S | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index c1c7456..c2bae92 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S

@@ -30,7 +30,7 @@
  *	r9, r10, r11 are clobbered by this function
  * No other registers are examined or changed.
  */
-_GLOBAL(slb_allocate_realmode)
+_GLOBAL_NOKPROBE(slb_allocate_realmode)

I think I'd prefer we just leave these as is, and add somewhere nearby:

_ASM_NOKPROBE_SYMBOL(slb_allocate_realmode)


It means someone reading the code doesn't need to worry about the
nokprobe part, just to understand the function. It also means we need
fewer macros :)

:)
Ok.

- Naveen