From: Will Deacon <will@kernel.org> To: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon <will@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Marc Zyngier <maz@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Peter Zijlstra <peterz@infradead.org>, Morten Rasmussen <morten.rasmussen@arm.com>, Qais Yousef <qais.yousef@arm.com>, Suren Baghdasaryan <surenb@google.com>, Quentin Perret <qperret@google.com>, Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>, Johannes Weiner <hannes@cmpxchg.org>, Ingo Molnar <mingo@redhat.com>, Juri Lelli <juri.lelli@redhat.com>, Vincent Guittot <vincent.guittot@linaro.org>, kernel-team@android.com Subject: [PATCH v3 05/14] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Date: Fri, 13 Nov 2020 09:37:10 +0000 [thread overview] Message-ID: <20201113093720.21106-6-will@kernel.org> (raw) In-Reply-To: <20201113093720.21106-1-will@kernel.org> Since 32-bit applications will be killed if they are caught trying to execute on a 64-bit-only CPU in a mismatched system, advertise the set of 32-bit capable CPUs to userspace in sysfs. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Will Deacon <will@kernel.org> --- .../ABI/testing/sysfs-devices-system-cpu | 9 +++++++++ arch/arm64/kernel/cpufeature.c | 19 +++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 1a04ca8162ad..8a2e377b0dde 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -493,6 +493,15 @@ Description: AArch64 CPU registers 'identification' directory exposes the CPU ID registers for identifying model and revision of the CPU. +What: /sys/devices/system/cpu/aarch32_el0 +Date: November 2020 +Contact: Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org> +Description: Identifies the subset of CPUs in the system that can execute + AArch32 (32-bit ARM) applications. If present, the same format as + /sys/devices/system/cpu/{offline,online,possible,present} is used. + If absent, then all or none of the CPUs can execute AArch32 + applications and execve() will behave accordingly. + What: /sys/devices/system/cpu/cpu#/cpu_capacity Date: December 2016 Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 1aa01ecc133f..a7a9b7bffc49 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -67,6 +67,7 @@ #include <linux/crash_dump.h> #include <linux/sort.h> #include <linux/stop_machine.h> +#include <linux/sysfs.h> #include <linux/types.h> #include <linux/mm.h> #include <linux/cpu.h> @@ -1272,6 +1273,24 @@ const struct cpumask *system_32bit_el0_cpumask(void) return cpu_present_mask; } +static ssize_t aarch32_el0_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct cpumask *mask = system_32bit_el0_cpumask(); + + return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(mask)); +} +static const DEVICE_ATTR_RO(aarch32_el0); + +static int __init aarch32_el0_sysfs_init(void) +{ + if (!allow_mismatched_32bit_el0) + return 0; + + return device_create_file(cpu_subsys.dev_root, &dev_attr_aarch32_el0); +} +device_initcall(aarch32_el0_sysfs_init); + static bool has_32bit_el0(const struct arm64_cpu_capabilities *entry, int scope) { if (!has_cpuid_feature(entry, scope)) -- 2.29.2.299.gdc1121823c-goog
WARNING: multiple messages have this Message-ID (diff)
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 05/14] arm64: Advertise CPUs capable of running 32-bit applications in sysfs Date: Fri, 13 Nov 2020 09:37:10 +0000 [thread overview] Message-ID: <20201113093720.21106-6-will@kernel.org> (raw) In-Reply-To: <20201113093720.21106-1-will@kernel.org> Since 32-bit applications will be killed if they are caught trying to execute on a 64-bit-only CPU in a mismatched system, advertise the set of 32-bit capable CPUs to userspace in sysfs. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Will Deacon <will@kernel.org> --- .../ABI/testing/sysfs-devices-system-cpu | 9 +++++++++ arch/arm64/kernel/cpufeature.c | 19 +++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 1a04ca8162ad..8a2e377b0dde 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -493,6 +493,15 @@ Description: AArch64 CPU registers 'identification' directory exposes the CPU ID registers for identifying model and revision of the CPU. +What: /sys/devices/system/cpu/aarch32_el0 +Date: November 2020 +Contact: Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org> +Description: Identifies the subset of CPUs in the system that can execute + AArch32 (32-bit ARM) applications. If present, the same format as + /sys/devices/system/cpu/{offline,online,possible,present} is used. + If absent, then all or none of the CPUs can execute AArch32 + applications and execve() will behave accordingly. + What: /sys/devices/system/cpu/cpu#/cpu_capacity Date: December 2016 Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 1aa01ecc133f..a7a9b7bffc49 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -67,6 +67,7 @@ #include <linux/crash_dump.h> #include <linux/sort.h> #include <linux/stop_machine.h> +#include <linux/sysfs.h> #include <linux/types.h> #include <linux/mm.h> #include <linux/cpu.h> @@ -1272,6 +1273,24 @@ const struct cpumask *system_32bit_el0_cpumask(void) return cpu_present_mask; } +static ssize_t aarch32_el0_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + const struct cpumask *mask = system_32bit_el0_cpumask(); + + return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(mask)); +} +static const DEVICE_ATTR_RO(aarch32_el0); + +static int __init aarch32_el0_sysfs_init(void) +{ + if (!allow_mismatched_32bit_el0) + return 0; + + return device_create_file(cpu_subsys.dev_root, &dev_attr_aarch32_el0); +} +device_initcall(aarch32_el0_sysfs_init); + static bool has_32bit_el0(const struct arm64_cpu_capabilities *entry, int scope) { if (!has_cpuid_feature(entry, scope)) -- 2.29.2.299.gdc1121823c-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-11-13 9:38 UTC|newest] Thread overview: 104+ 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 ` 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 ` Will Deacon 2020-11-13 9:37 ` [PATCH v3 02/14] arm64: Allow mismatched 32-bit EL0 support Will Deacon 2020-11-13 9:37 ` Will Deacon 2020-11-19 11:27 ` Valentin Schneider 2020-11-19 11:27 ` Valentin Schneider 2020-11-19 13:12 ` Will Deacon 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 ` 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 ` Will Deacon 2020-11-13 9:37 ` Will Deacon [this message] 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 ` [PATCH v3 06/14] arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0 Will Deacon 2020-11-13 9:37 ` Will Deacon 2020-11-13 9:37 ` [PATCH v3 07/14] sched: Introduce restrict_cpus_allowed_ptr() to limit task CPU affinity Will Deacon 2020-11-13 9:37 ` Will Deacon 2020-11-19 9:18 ` Quentin Perret 2020-11-19 9:18 ` Quentin Perret 2020-11-19 11:03 ` Quentin Perret 2020-11-19 11:03 ` Quentin Perret 2020-11-19 11:05 ` Will Deacon 2020-11-19 11:05 ` Will Deacon 2020-11-19 11:27 ` Valentin Schneider 2020-11-19 11:27 ` Valentin Schneider 2020-11-19 13:13 ` Will Deacon 2020-11-19 13:13 ` Will Deacon 2020-11-19 14:54 ` Valentin Schneider 2020-11-19 14:54 ` Valentin Schneider 2020-11-19 16:41 ` Will Deacon 2020-11-19 16:41 ` Will Deacon 2020-11-19 12:47 ` Valentin Schneider 2020-11-19 12:47 ` Valentin Schneider 2020-11-19 13:13 ` Will Deacon 2020-11-19 13:13 ` Will Deacon 2020-11-19 14:54 ` Valentin Schneider 2020-11-19 14:54 ` Valentin Schneider 2020-11-19 16:09 ` Peter Zijlstra 2020-11-19 16:09 ` Peter Zijlstra 2020-11-19 16:57 ` Valentin Schneider 2020-11-19 16:57 ` Valentin Schneider 2020-11-19 19:25 ` Will Deacon 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 2020-11-13 9:37 ` Will Deacon 2020-11-19 9:24 ` Quentin Perret 2020-11-19 9:24 ` Quentin Perret 2020-11-19 11:06 ` Will Deacon 2020-11-19 11:06 ` Will Deacon 2020-11-19 16:19 ` Peter Zijlstra 2020-11-19 16:19 ` Peter Zijlstra 2020-11-19 16:30 ` Will Deacon 2020-11-19 16:30 ` Will Deacon 2020-11-19 16:44 ` Peter Zijlstra 2020-11-19 16:44 ` Peter Zijlstra 2020-11-19 16:51 ` Will Deacon 2020-11-19 16:51 ` Will Deacon 2020-11-19 16:14 ` Peter Zijlstra 2020-11-19 16:14 ` Peter Zijlstra 2020-11-19 16:28 ` Will Deacon 2020-11-19 16:28 ` Will Deacon 2020-11-19 16:42 ` Peter Zijlstra 2020-11-19 16:42 ` Peter Zijlstra 2020-11-19 16:48 ` Will Deacon 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 2020-11-13 9:37 ` Will Deacon 2020-11-19 9:29 ` Quentin Perret 2020-11-19 9:29 ` Quentin Perret 2020-11-19 11:06 ` Will Deacon 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 2020-11-13 9:37 ` Will Deacon 2020-11-19 9:38 ` Quentin Perret 2020-11-19 9:38 ` Quentin Perret 2020-11-19 11:07 ` Will Deacon 2020-11-19 11:07 ` Will Deacon 2020-11-19 20:39 ` Will Deacon 2020-11-19 20:39 ` Will Deacon 2020-11-23 14:48 ` Quentin Perret 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 2020-11-13 9:37 ` Will Deacon 2020-11-19 9:47 ` Quentin Perret 2020-11-19 9:47 ` Quentin Perret 2020-11-19 11:07 ` Will Deacon 2020-11-19 11:07 ` Will Deacon 2020-11-19 14:30 ` Quentin Perret 2020-11-19 14:30 ` Quentin Perret 2020-11-19 16:44 ` Will Deacon 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 ` Will Deacon 2020-11-13 9:37 ` [PATCH v3 13/14] arm64: Implement arch_cpu_allowed_mask() Will Deacon 2020-11-13 9:37 ` 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 2020-11-13 9:37 ` Will Deacon 2020-11-19 16:11 ` [PATCH v3 00/14] An alternative series for asymmetric AArch32 systems Peter Zijlstra 2020-11-19 16:11 ` Peter Zijlstra 2020-11-19 16:39 ` Will Deacon 2020-11-19 16:39 ` Will Deacon
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