From: Jeremy Linton <jeremy.linton@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: catalin.marinas@arm.com, will.deacon@arm.com,
marc.zyngier@arm.com, suzuki.poulose@arm.com,
dave.martin@arm.com, shankerd@codeaurora.org,
mark.rutland@arm.com, linux-kernel@vger.kernel.org,
ykaukab@suse.de, Jeremy Linton <jeremy.linton@arm.com>
Subject: [PATCH 1/6] arm64: kpti: move check for non-vulnerable CPUs to a function
Date: Thu, 6 Dec 2018 17:44:03 -0600 [thread overview]
Message-ID: <20181206234408.1287689-2-jeremy.linton@arm.com> (raw)
In-Reply-To: <20181206234408.1287689-1-jeremy.linton@arm.com>
From: Mian Yousaf Kaukab <ykaukab@suse.de>
Add is_meltdown_safe() which is a whitelist of known safe cores.
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
[Moved location of function]
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
---
arch/arm64/kernel/cpufeature.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index aec5ecb85737..242898395f68 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -908,8 +908,7 @@ has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
static int __kpti_forced; /* 0: not forced, >0: forced on, <0: forced off */
-static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
- int scope)
+static bool is_cpu_meltdown_safe(void)
{
/* List of CPUs that are not vulnerable and don't need KPTI */
static const struct midr_range kpti_safe_list[] = {
@@ -917,6 +916,16 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
{ /* sentinel */ }
};
+ /* Don't force KPTI for CPUs that are not vulnerable */
+ if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list))
+ return true;
+
+ return false;
+}
+
+static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
+ int scope)
+{
char const *str = "command line option";
/*
@@ -940,8 +949,7 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
return true;
- /* Don't force KPTI for CPUs that are not vulnerable */
- if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list))
+ if (is_cpu_meltdown_safe())
return false;
/* Defer to CPU feature registers */
--
2.17.2
next prev parent reply other threads:[~2018-12-06 23:44 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-06 23:44 [PATCH 0/6] add system vulnerability sysfs entries Jeremy Linton
2018-12-06 23:44 ` Jeremy Linton [this message]
2018-12-13 9:13 ` [PATCH 1/6] arm64: kpti: move check for non-vulnerable CPUs to a function Julien Thierry
2018-12-12 14:36 ` Jeremy Linton
2018-12-06 23:44 ` [PATCH 2/6] arm64: add sysfs vulnerability show for meltdown Jeremy Linton
2018-12-13 9:23 ` Julien Thierry
2018-12-13 10:46 ` Julien Thierry
2018-12-12 14:49 ` Jeremy Linton
2018-12-14 8:55 ` Julien Thierry
2018-12-06 23:44 ` [PATCH 3/6] arm64: add sysfs vulnerability show for spectre v1 Jeremy Linton
2018-12-06 23:44 ` [PATCH 4/6] arm64: add sysfs vulnerability show for spectre v2 Jeremy Linton
2018-12-13 11:09 ` Julien Thierry
2019-01-02 22:19 ` Jeremy Linton
2018-12-06 23:44 ` [PATCH 5/6] arm64: add sysfs vulnerability show for speculative store bypass Jeremy Linton
2018-12-14 10:34 ` Steven Price
2018-12-14 10:36 ` Will Deacon
2018-12-14 10:41 ` Steven Price
2018-12-14 11:28 ` Dave Martin
2018-12-14 11:33 ` Will Deacon
2018-12-06 23:44 ` [PATCH 6/6] arm64: enable generic CPU vulnerabilites support Jeremy Linton
2018-12-13 12:07 ` [PATCH 0/6] add system vulnerability sysfs entries Dave Martin
2018-12-12 15:48 ` Jeremy Linton
2018-12-13 19:26 ` Dave Martin
-- strict thread matches above, loose matches on Subject: below --
2018-08-07 18:14 [PATCH 0/6] arm64: add support for generic cpu vulnerabilities Mian Yousaf Kaukab
2018-08-07 18:14 ` [PATCH 1/6] arm64: kpti: move check for non-vulnerable CPUs to a function Mian Yousaf Kaukab
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