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From:   Christophe Leroy <christophe.leroy@c-s.fr>
Subject: [PATCH 04/12] powerpc/powermac: Blacklist functions running with MMU
 disabled for kprobe
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        naveen.n.rao@linux.vnet.ibm.com
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Date:   Sun, 29 Mar 2020 09:41:04 +0000 (UTC)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

kprobe does not handle events happening in real mode, all
functions running with MMU disabled have to be blacklisted.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/platforms/powermac/cache.S | 2 ++
 arch/powerpc/platforms/powermac/sleep.S | 5 ++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powermac/cache.S b/arch/powerpc/platforms/powermac/cache.S
index da69e0fcb4f1..ced225415486 100644
--- a/arch/powerpc/platforms/powermac/cache.S
+++ b/arch/powerpc/platforms/powermac/cache.S
@@ -184,6 +184,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 
 	mtlr	r10
 	blr
+_ASM_NOKPROBE_SYMBOL(flush_disable_75x)
 
 /* This code is for 745x processors */
 flush_disable_745x:
@@ -351,4 +352,5 @@ END_FTR_SECTION_IFSET(CPU_FTR_L3CR)
 	mtmsr	r11		/* restore DR and EE */
 	isync
 	blr
+_ASM_NOKPROBE_SYMBOL(flush_disable_745x)
 #endif	/* CONFIG_PPC_BOOK3S_32 */
diff --git a/arch/powerpc/platforms/powermac/sleep.S b/arch/powerpc/platforms/powermac/sleep.S
index bd6085b470b7..f9a680fdd9c4 100644
--- a/arch/powerpc/platforms/powermac/sleep.S
+++ b/arch/powerpc/platforms/powermac/sleep.S
@@ -244,7 +244,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450)
 	mtmsr	r2
 	isync
 	b	1b
-
+_ASM_NOKPROBE_SYMBOL(low_cpu_die)
 /*
  * Here is the resume code.
  */
@@ -282,6 +282,7 @@ _GLOBAL(core99_wake_up)
 	lwz	r1,0(r3)
 
 	/* Pass thru to older resume code ... */
+_ASM_NOKPROBE_SYMBOL(core99_wake_up)
 /*
  * Here is the resume code for older machines.
  * r1 has the physical address of SL_PC(sp).
@@ -429,6 +430,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
 	lwz	r0,4(r1)
 	mtlr	r0
 	blr
+_ASM_NOKPROBE_SYMBOL(grackle_wake_up)
 
 turn_on_mmu:
 	mflr	r4
@@ -438,6 +440,7 @@ turn_on_mmu:
 	sync
 	isync
 	rfi
+_ASM_NOKPROBE_SYMBOL(turn_on_mmu)
 
 #endif /* defined(CONFIG_PM) || defined(CONFIG_CPU_FREQ) */
 
-- 
2.25.0