[PATCH v4 7/7] powerpc/64s: Blacklist rtas entry/exit from kprobes

[Naveen N. Rao]

We can't take traps with relocation off, so blacklist enter_rtas() and
rtas_return_loc(). However, instead of blacklisting all of enter_rtas(),
introduce a new symbol __enter_rtas from where on we can't take a trap
and blacklist that.

Signed-off-by: Naveen N. Rao <naveen.n.rao at linux.vnet.ibm.com>
---
 arch/powerpc/kernel/entry_64.S | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 0c27084800b6..16f4c4a1a294 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -1082,6 +1082,7 @@ _GLOBAL(enter_rtas)
 	sync				/* disable interrupts so SRR0/1 */
 	mtmsrd	r0			/* don't get trashed */
 
+__enter_rtas:
 	LOAD_REG_ADDR(r4, rtas)
 	ld	r5,RTASENTRY(r4)	/* get the rtas->entry value */
 	ld	r4,RTASBASE(r4)		/* get the rtas->base value */
@@ -1115,6 +1116,8 @@ rtas_return_loc:
 	mtspr	SPRN_SRR1,r4
 	rfid
 	b	.	/* prevent speculative execution */
+_ASM_NOKPROBE_SYMBOL(__enter_rtas)
+_ASM_NOKPROBE_SYMBOL(rtas_return_loc)
 
 	.align	3
 1:	.llong	rtas_restore_regs
-- 
2.13.1