From: Will Deacon <will@kernel•org>
To: linux-arm-kernel@lists•infradead.org
Cc: linux-arch@vger•kernel.org, Marc Zyngier <maz@kernel•org>,
kernel-team@android•com,
Vincent Guittot <vincent.guittot@linaro•org>,
Juri Lelli <juri.lelli@redhat•com>,
Quentin Perret <qperret@google•com>,
Peter Zijlstra <peterz@infradead•org>,
Catalin Marinas <catalin.marinas@arm•com>,
Johannes Weiner <hannes@cmpxchg•org>,
linux-kernel@vger•kernel.org, Qais Yousef <qais.yousef@arm•com>,
Suren Baghdasaryan <surenb@google•com>,
Ingo Molnar <mingo@redhat•com>, Li Zefan <lizefan@huawei•com>,
Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
Tejun Heo <tj@kernel•org>, Will Deacon <will@kernel•org>,
Morten Rasmussen <morten.rasmussen@arm•com>
Subject: [PATCH v3 06/14] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0
Date: Fri, 13 Nov 2020 09:37:11 +0000 [thread overview]
Message-ID: <20201113093720.21106-7-will@kernel.org> (raw)
In-Reply-To: <20201113093720.21106-1-will@kernel.org>
Allow systems with mismatched 32-bit support at EL0 to run 32-bit
applications based on a new kernel parameter.
Signed-off-by: Will Deacon <will@kernel•org>
---
Documentation/admin-guide/kernel-parameters.txt | 7 +++++++
arch/arm64/kernel/cpufeature.c | 7 +++++++
2 files changed, 14 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 526d65d8573a..f20188c44d83 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -289,6 +289,13 @@
do not want to use tracing_snapshot_alloc() as it needs
to be done where GFP_KERNEL allocations are allowed.
+ allow_mismatched_32bit_el0 [ARM64]
+ Allow execve() of 32-bit applications and setting of the
+ PER_LINUX32 personality on systems where only a strict
+ subset of the CPUs support 32-bit EL0. When this
+ parameter is present, the set of CPUs supporting 32-bit
+ EL0 is indicated by /sys/devices/system/cpu/aarch32_el0.
+
amd_iommu= [HW,X86-64]
Pass parameters to the AMD IOMMU driver in the system.
Possible values are:
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index a7a9b7bffc49..dfded018af44 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1273,6 +1273,13 @@ const struct cpumask *system_32bit_el0_cpumask(void)
return cpu_present_mask;
}
+static int __init parse_32bit_el0_param(char *str)
+{
+ allow_mismatched_32bit_el0 = true;
+ return 0;
+}
+early_param("allow_mismatched_32bit_el0", parse_32bit_el0_param);
+
static ssize_t aarch32_el0_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
--
2.29.2.299.gdc1121823c-goog
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next prev parent reply other threads:[~2020-11-13 9:39 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-13 9:37 [PATCH v3 00/14] An alternative series for asymmetric AArch32 systems Will Deacon
2020-11-13 9:37 ` [PATCH v3 01/14] arm64: cpuinfo: Split AArch32 registers out into a separate struct Will Deacon
2020-11-13 9:37 ` [PATCH v3 02/14] arm64: Allow mismatched 32-bit EL0 support Will Deacon
2020-11-19 11:27 ` Valentin Schneider
2020-11-19 13:12 ` Will Deacon
2020-11-13 9:37 ` [PATCH v3 03/14] KVM: arm64: Kill 32-bit vCPUs on systems with mismatched " Will Deacon
2020-11-13 9:37 ` [PATCH v3 04/14] arm64: Kill 32-bit applications scheduled on 64-bit-only CPUs Will Deacon
2020-11-13 9:37 ` [PATCH v3 05/14] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Will Deacon
2020-11-13 9:37 ` Will Deacon [this message]
2020-11-13 9:37 ` [PATCH v3 07/14] sched: Introduce restrict_cpus_allowed_ptr() to limit task CPU affinity Will Deacon
2020-11-19 9:18 ` Quentin Perret
2020-11-19 11:03 ` Quentin Perret
2020-11-19 11:05 ` Will Deacon
2020-11-19 11:27 ` Valentin Schneider
2020-11-19 13:13 ` Will Deacon
2020-11-19 14:54 ` Valentin Schneider
2020-11-19 16:41 ` Will Deacon
2020-11-19 12:47 ` Valentin Schneider
2020-11-19 13:13 ` Will Deacon
2020-11-19 14:54 ` Valentin Schneider
2020-11-19 16:09 ` Peter Zijlstra
2020-11-19 16:57 ` Valentin Schneider
2020-11-19 19:25 ` Will Deacon
2020-11-13 9:37 ` [PATCH v3 08/14] arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0 Will Deacon
2020-11-19 9:24 ` Quentin Perret
2020-11-19 11:06 ` Will Deacon
2020-11-19 16:19 ` Peter Zijlstra
2020-11-19 16:30 ` Will Deacon
2020-11-19 16:44 ` Peter Zijlstra
2020-11-19 16:51 ` Will Deacon
2020-11-19 16:14 ` Peter Zijlstra
2020-11-19 16:28 ` Will Deacon
2020-11-19 16:42 ` Peter Zijlstra
2020-11-19 16:48 ` Will Deacon
2020-11-13 9:37 ` [PATCH v3 09/14] cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1 Will Deacon
2020-11-19 9:29 ` Quentin Perret
2020-11-19 11:06 ` Will Deacon
2020-11-13 9:37 ` [PATCH v3 10/14] sched: Introduce arch_cpu_allowed_mask() to limit fallback rq selection Will Deacon
2020-11-19 9:38 ` Quentin Perret
2020-11-19 11:07 ` Will Deacon
2020-11-19 20:39 ` Will Deacon
2020-11-23 14:48 ` Quentin Perret
2020-11-13 9:37 ` [PATCH v3 11/14] sched: Reject CPU affinity changes based on arch_cpu_allowed_mask() Will Deacon
2020-11-19 9:47 ` Quentin Perret
2020-11-19 11:07 ` Will Deacon
2020-11-19 14:30 ` Quentin Perret
2020-11-19 16:44 ` Will Deacon
2020-11-13 9:37 ` [PATCH v3 12/14] arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system Will Deacon
2020-11-13 9:37 ` [PATCH v3 13/14] arm64: Implement arch_cpu_allowed_mask() Will Deacon
2020-11-13 9:37 ` [PATCH v3 14/14] arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores Will Deacon
2020-11-19 16:11 ` [PATCH v3 00/14] An alternative series for asymmetric AArch32 systems Peter Zijlstra
2020-11-19 16:39 ` Will Deacon
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