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From: Rob Herring <robh@kernel.org>
To: Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Jiri Olsa <jolsa@redhat.com>, Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	honnappa.nagarahalli@arm.com, Zachary.Leaf@arm.com,
	Raphael Gault <raphael.gault@arm.com>,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Itaru Kitayama <itaru.kitayama@gmail.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v7 1/9] arm64: Restrict undef hook for cpufeature registers
Date: Mon, 19 Apr 2021 22:15:03 -0500	[thread overview]
Message-ID: <20210420031511.2348977-2-robh@kernel.org> (raw)
In-Reply-To: <20210420031511.2348977-1-robh@kernel.org>

From: Raphael Gault <raphael.gault@arm.com>

This commit modifies the mask of the mrs_hook declared in
arch/arm64/kernel/cpufeatures.c which emulates only feature register
access. This is necessary because this hook's mask was too large and
thus masking any mrs instruction, even if not related to the emulated
registers which made the pmu emulation inefficient.

Signed-off-by: Raphael Gault <raphael.gault@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
---
v7:
 - Split off from Raphael's original undef hook patch as this change stands
   on its own.
---
 arch/arm64/kernel/cpufeature.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 066030717a4c..aa0777690ab1 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2888,8 +2888,8 @@ static int emulate_mrs(struct pt_regs *regs, u32 insn)
 }

 static struct undef_hook mrs_hook = {
-	.instr_mask = 0xfff00000,
-	.instr_val  = 0xd5300000,
+	.instr_mask = 0xffff0000,
+	.instr_val  = 0xd5380000,
 	.pstate_mask = PSR_AA32_MODE_MASK,
 	.pstate_val = PSR_MODE_EL0t,
 	.fn = emulate_mrs,
--
2.27.0

WARNING: multiple messages have this Message-ID
From: Rob Herring <robh@kernel.org>
To: Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Jiri Olsa <jolsa@redhat.com>, Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	honnappa.nagarahalli@arm.com, Zachary.Leaf@arm.com,
	Raphael Gault <raphael.gault@arm.com>,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Itaru Kitayama <itaru.kitayama@gmail.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v7 1/9] arm64: Restrict undef hook for cpufeature registers
Date: Mon, 19 Apr 2021 22:15:03 -0500	[thread overview]
Message-ID: <20210420031511.2348977-2-robh@kernel.org> (raw)
In-Reply-To: <20210420031511.2348977-1-robh@kernel.org>

From: Raphael Gault <raphael.gault@arm.com>

This commit modifies the mask of the mrs_hook declared in
arch/arm64/kernel/cpufeatures.c which emulates only feature register
access. This is necessary because this hook's mask was too large and
thus masking any mrs instruction, even if not related to the emulated
registers which made the pmu emulation inefficient.

Signed-off-by: Raphael Gault <raphael.gault@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
---
v7:
 - Split off from Raphael's original undef hook patch as this change stands
   on its own.
---
 arch/arm64/kernel/cpufeature.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 066030717a4c..aa0777690ab1 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2888,8 +2888,8 @@ static int emulate_mrs(struct pt_regs *regs, u32 insn)
 }

 static struct undef_hook mrs_hook = {
-	.instr_mask = 0xfff00000,
-	.instr_val  = 0xd5300000,
+	.instr_mask = 0xffff0000,
+	.instr_val  = 0xd5380000,
 	.pstate_mask = PSR_AA32_MODE_MASK,
 	.pstate_val = PSR_MODE_EL0t,
 	.fn = emulate_mrs,
--
2.27.0

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  reply	other threads:[~2021-04-20  3:15 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-20  3:15 [PATCH v7 0/9] arm64 userspace counter access support Rob Herring
2021-04-20  3:15 ` Rob Herring
2021-04-20  3:15 ` Rob Herring [this message]
2021-04-20  3:15   ` [PATCH v7 1/9] arm64: Restrict undef hook for cpufeature registers Rob Herring
2021-04-20  3:15 ` [PATCH v7 2/9] arm64: pmu: Add function implementation to update event index in userpage Rob Herring
2021-04-20  3:15   ` Rob Herring
2021-04-20  3:15 ` [PATCH v7 3/9] arm64: perf: Enable PMU counter direct access for perf event Rob Herring
2021-04-20  3:15   ` Rob Herring
2021-04-20  3:15 ` [PATCH v7 4/9] drivers/perf: arm_pmu: Export the per_cpu cpu_armpmu Rob Herring
2021-04-20  3:15   ` Rob Herring
2021-04-20  3:15 ` [PATCH v7 5/9] arm64: perf: Add userspace counter access disable switch Rob Herring
2021-04-20  3:15   ` Rob Herring
2021-04-20  3:15 ` [PATCH v7 6/9] libperf: Add arm64 support to perf_mmap__read_self() Rob Herring
2021-04-20  3:15   ` Rob Herring
2021-04-20  3:15 ` [PATCH v7 7/9] perf: arm64: Add test for userspace counter access on heterogeneous systems Rob Herring
2021-04-20  3:15   ` Rob Herring
2021-04-30 16:46   ` Masayoshi Mizuma
2021-04-30 16:46     ` Masayoshi Mizuma
2021-04-30 18:17     ` Rob Herring
2021-04-30 18:17       ` Rob Herring
2021-04-30 18:20       ` Rob Herring
2021-04-30 18:20         ` Rob Herring
2021-04-30 20:16         ` Masayoshi Mizuma
2021-04-30 20:16           ` Masayoshi Mizuma
2021-05-13  9:05   ` nakamura.shun
2021-05-13  9:05     ` nakamura.shun
2021-05-13 12:37     ` Rob Herring
2021-05-13 12:37       ` Rob Herring
2021-04-20  3:15 ` [PATCH v7 8/9] perf: arm64: Add tests for 32-bit and 64-bit counter size userspace access Rob Herring
2021-04-20  3:15   ` Rob Herring
2021-04-20  3:15 ` [PATCH v7 9/9] Documentation: arm64: Document PMU counters access from userspace Rob Herring
2021-04-20  3:15   ` Rob Herring
2021-04-30 18:59 ` [PATCH v7 0/9] arm64 userspace counter access support Arnaldo Carvalho de Melo
2021-04-30 18:59   ` Arnaldo Carvalho de Melo
2021-05-03 14:56   ` Rob Herring
2021-05-03 14:56     ` Rob Herring

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