From: Mark Brown <broonie@kernel.org>
To: Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Brown <broonie@kernel.org>, linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 3/3] arm64: insn: Report PAC and BTI instructions as NOPs
Date: Tue, 28 Apr 2020 18:24:33 +0100 [thread overview]
Message-ID: <20200428172433.48830-4-broonie@kernel.org> (raw)
In-Reply-To: <20200428172433.48830-1-broonie@kernel.org>
In order to allow probing of PAC and BTI instructions without more
specialized support recognize them as NOPs.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
---
arch/arm64/kernel/insn.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index fd77cdd87c47..82afc582d29a 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -57,7 +57,27 @@ bool __kprobes aarch64_insn_is_nop(u32 insn)
if (!aarch64_insn_is_hint(insn))
return false;
+ /*
+ * The PAC and BTI instructons are not strictly NOPs but until
+ * better support is added we can treat them as such.
+ */
switch (insn & 0xFE0) {
+ case AARCH64_INSN_HINT_PACIA_1716:
+ case AARCH64_INSN_HINT_PACIB_1716:
+ case AARCH64_INSN_HINT_AUTIA_1716:
+ case AARCH64_INSN_HINT_AUTIB_1716:
+ case AARCH64_INSN_HINT_PACIAZ:
+ case AARCH64_INSN_HINT_PACIASP:
+ case AARCH64_INSN_HINT_PACIBZ:
+ case AARCH64_INSN_HINT_PACIBSP:
+ case AARCH64_INSN_HINT_AUTIAZ:
+ case AARCH64_INSN_HINT_AUTIASP:
+ case AARCH64_INSN_HINT_AUTIBZ:
+ case AARCH64_INSN_HINT_AUTIBSP:
+ case AARCH64_INSN_HINT_BTI:
+ case AARCH64_INSN_HINT_BTIC:
+ case AARCH64_INSN_HINT_BTIJ:
+ case AARCH64_INSN_HINT_BTIJC:
case AARCH64_INSN_HINT_NOP:
return true;
default:
--
2.20.1
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next prev parent reply other threads:[~2020-04-28 17:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 17:24 [PATCH v2 0/3] arm64: Make NOP handling a whitelist Mark Brown
2020-04-28 17:24 ` [PATCH v2 1/3] arm64: insn: Don't assume unrecognized HINTs are NOPs Mark Brown
2020-04-30 16:08 ` Will Deacon
2020-04-28 17:24 ` [PATCH v2 2/3] arm64: insn: Add constants for PAC and BTI instruction decode Mark Brown
2020-04-30 16:07 ` Will Deacon
2020-04-30 16:45 ` Mark Brown
2020-04-28 17:24 ` Mark Brown [this message]
2020-04-30 16:09 ` [PATCH v2 3/3] arm64: insn: Report PAC and BTI instructions as NOPs Will Deacon
2020-04-30 17:16 ` Mark Brown
2020-04-30 17:20 ` Will Deacon
2020-04-30 17:36 ` Mark Brown
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