From: Andrea della Porta <andrea.porta@suse.com>
To: Jonathan Corbet <corbet@lwn.net>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Cc: Andrea della Porta <andrea.porta@suse.com>
Subject: [PATCH v3] arm64: Add the arm64.no32bit_el0 command line option
Date: Mon, 29 Apr 2024 12:28:33 +0200 [thread overview]
Message-ID: <20240429102833.6426-1-andrea.porta@suse.com> (raw)
Introducing the field 'el0' to the idreg-override for register
ID_AA64PFR0_EL1. This field is also aliased to the new kernel
command line option 'arm64.no32bit_el0' as a more recognizable
and mnemonic name to disable the execution of 32 bit userspace
applications (i.e. avoid Aarch32 execution state in EL0) from
kernel command line.
Changes in V3:
- idreg-override.c has been moved to arch/arm64/kernel/pi/
directory, so this patch revision adjust for that change.
Link: https://lore.kernel.org/all/20240207105847.7739-1-andrea.porta@suse.com/
Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
---
Documentation/admin-guide/kernel-parameters.txt | 3 +++
arch/arm64/kernel/pi/idreg-override.c | 2 ++
2 files changed, 5 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index bb884c14b2f6..3e70963599df 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -431,6 +431,9 @@
arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
Format: <io>,<irq>,<nodeID>
+ arm64.no32bit_el0 [ARM64] Unconditionally disable the execution of
+ 32 bit applications.
+
arm64.nobti [ARM64] Unconditionally disable Branch Target
Identification support
diff --git a/arch/arm64/kernel/pi/idreg-override.c b/arch/arm64/kernel/pi/idreg-override.c
index aad399796e81..48c1aa456af9 100644
--- a/arch/arm64/kernel/pi/idreg-override.c
+++ b/arch/arm64/kernel/pi/idreg-override.c
@@ -108,6 +108,7 @@ static const struct ftr_set_desc pfr0 __prel64_initconst = {
.override = &id_aa64pfr0_override,
.fields = {
FIELD("sve", ID_AA64PFR0_EL1_SVE_SHIFT, pfr0_sve_filter),
+ FIELD("el0", ID_AA64PFR0_EL1_EL0_SHIFT, NULL),
{}
},
};
@@ -223,6 +224,7 @@ static const struct {
{ "nokaslr", "arm64_sw.nokaslr=1" },
{ "rodata=off", "arm64_sw.rodataoff=1" },
{ "arm64.nolva", "id_aa64mmfr2.varange=0" },
+ { "arm64.no32bit_el0", "id_aa64pfr0.el0=1" },
};
static int __init parse_hexdigit(const char *p, u64 *v)
--
2.35.3
next reply other threads:[~2024-04-29 10:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-29 10:28 Andrea della Porta [this message]
2024-05-03 17:32 ` [PATCH v3] arm64: Add the arm64.no32bit_el0 command line option Will Deacon
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