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author | Jeremy Linton <jeremy.linton@arm.com> | 2019-10-08 17:39:24 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-11 18:21:34 +0200 |
commit | 59a6dc262c8500c6e5fb9f234c6078fd72ddc20f (patch) | |
tree | e1428178806bf9080a9d3c35251bdc62fdd6a79e /arch | |
parent | c131623b1e9d94c11e2db4635c4572a85fd8b3ce (diff) | |
download | linux-stable-59a6dc262c8500c6e5fb9f234c6078fd72ddc20f.tar.gz linux-stable-59a6dc262c8500c6e5fb9f234c6078fd72ddc20f.tar.bz2 linux-stable-59a6dc262c8500c6e5fb9f234c6078fd72ddc20f.zip |
arm64: Provide a command line to disable spectre_v2 mitigation
[ Upstream commit e5ce5e7267ddcbe13ab9ead2542524e1b7993e5a ]
There are various reasons, such as benchmarking, to disable spectrev2
mitigation on a machine. Provide a command-line option to do so.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 10571a378f4c..2394a105ebf4 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -189,6 +189,14 @@ static void qcom_link_stack_sanitization(void) : "=&r" (tmp)); } +static bool __nospectre_v2; +static int __init parse_nospectre_v2(char *str) +{ + __nospectre_v2 = true; + return 0; +} +early_param("nospectre_v2", parse_nospectre_v2); + static void enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) { @@ -200,6 +208,11 @@ enable_smccc_arch_workaround_1(const struct arm64_cpu_capabilities *entry) if (!entry->matches(entry, SCOPE_LOCAL_CPU)) return; + if (__nospectre_v2) { + pr_info_once("spectrev2 mitigation disabled by command line option\n"); + return; + } + if (psci_ops.smccc_version == SMCCC_VERSION_1_0) return; |