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From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Nicholas Piggin <npiggin@gmail.com>,
	linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v3 6/6] powerpc/64s: Blacklist rtas entry/exit from kprobes
Date: Thu, 22 Jun 2017 00:08:42 +0530	[thread overview]
Message-ID: <482db382b611b0a97bb1d897b3b38cc083e10965.1498069502.git.naveen.n.rao@linux.vnet.ibm.com> (raw)
In-Reply-To: <cover.1498069502.git.naveen.n.rao@linux.vnet.ibm.com>
In-Reply-To: <cover.1498069502.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 | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index d376f07153d7..49c35450f399 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -1076,6 +1076,8 @@ _GLOBAL(enter_rtas)
         rldicr  r9,r9,MSR_SF_LG,(63-MSR_SF_LG)
 	ori	r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP|MSR_RI|MSR_LE
 	andc	r6,r0,r9
+
+__enter_rtas:
 	sync				/* disable interrupts so SRR0/1 */
 	mtmsrd	r0			/* don't get trashed */
 
@@ -1112,6 +1114,8 @@ 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:[~2017-06-21 18:39 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-21 18:38 [PATCH v3 0/6] powerpc: build out kprobes blacklist -- series 3 Naveen N. Rao
2017-06-21 18:38 ` [PATCH v3 1/6] powerpc64/elfv1: Validate function pointer address in the function descriptor Naveen N. Rao
2017-06-22  3:22   ` Nicholas Piggin
2017-06-22 10:59     ` Michael Ellerman
2017-06-22 13:06       ` Nicholas Piggin
2017-06-22 14:01         ` Naveen N. Rao
2017-06-21 18:38 ` [PATCH v3 2/6] powerpc/64s: Convert .L__replay_interrupt_return to a local label Naveen N. Rao
2017-06-22  3:23   ` Nicholas Piggin
2017-06-21 18:38 ` [PATCH v3 3/6] powerpc/64s: Blacklist system_call() and system_call_common() from kprobes Naveen N. Rao
2017-06-22  3:36   ` Nicholas Piggin
2017-06-22 11:07     ` Michael Ellerman
2017-06-22 13:08       ` Nicholas Piggin
2017-06-22 14:34         ` Naveen N. Rao
2017-06-21 18:38 ` [PATCH v3 4/6] powerpc/64s: Un-blacklist system_call() " Naveen N. Rao
2017-06-22  3:41   ` Nicholas Piggin
2017-06-22 11:14     ` Michael Ellerman
2017-06-22 13:14       ` Nicholas Piggin
2017-06-22 15:43         ` Naveen N. Rao
2017-06-21 18:38 ` [PATCH v3 5/6] powerpc/64s: Blacklist functions invoked on a trap Naveen N. Rao
2017-06-22  3:44   ` Nicholas Piggin
2017-06-22 11:12     ` Michael Ellerman
2017-06-21 18:38 ` Naveen N. Rao [this message]
2017-06-22  3:48   ` [PATCH v3 6/6] powerpc/64s: Blacklist rtas entry/exit from kprobes Nicholas Piggin
2017-06-22 16:52     ` Naveen N. Rao

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