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From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>,
	Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Anton Blanchard <anton@samba.org>,
	linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v4 7/7] powerpc/64s: Blacklist rtas entry/exit from kprobes
Date: Thu, 29 Jun 2017 16:11:10 +0530	[thread overview]
Message-ID: <39d40efd808c6346b97e5bfe4be47546919cb91b.1498732172.git.naveen.n.rao@linux.vnet.ibm.com> (raw)
In-Reply-To: <cover.1498732172.git.naveen.n.rao@linux.vnet.ibm.com>
In-Reply-To: <cover.1498732172.git.naveen.n.rao@linux.vnet.ibm.com>

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@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

  parent reply	other threads:[~2017-06-29 10:41 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-29 10:41 [PATCH v4 0/7] powerpc: build out kprobes blacklist -- series 3 Naveen N. Rao
2017-06-29 10:41 ` [PATCH v4 1/7] powerpc64/elfv1: Only dereference function descriptor for non-text symbols Naveen N. Rao
2017-06-29 10:49   ` Nicholas Piggin
2017-06-29 11:48     ` Naveen N. Rao
2017-06-29 10:41 ` [PATCH v4 2/7] powerpc/64s: Convert .L__replay_interrupt_return to a local label Naveen N. Rao
2017-06-29 10:41 ` [PATCH v4 3/7] powerpc/64s: Blacklist system_call() and system_call_common() from kprobes Naveen N. Rao
2017-06-29 10:41 ` [PATCH v4 4/7] powerpc/64s: Move system_call() symbol to just after setting MSR_EE Naveen N. Rao
2017-06-29 11:44   ` Nicholas Piggin
2017-06-29 10:41 ` [PATCH v4 5/7] powerpc/64s: Un-blacklist system_call() from kprobes Naveen N. Rao
2017-06-29 10:55   ` Nicholas Piggin
2017-06-29 11:51     ` Naveen N. Rao
2017-06-29 10:41 ` [PATCH v4 6/7] powerpc/64s: Blacklist functions invoked on a trap Naveen N. Rao
2017-06-29 10:41 ` Naveen N. Rao [this message]
2017-06-29 11:01   ` [PATCH v4 7/7] powerpc/64s: Blacklist rtas entry/exit from kprobes Nicholas Piggin
2017-06-29 11:54     ` Naveen N. Rao
2017-06-29 12:13       ` Nicholas Piggin
2017-06-29 16:51         ` Naveen N. Rao

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