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-rw-r--r--arch/arm64/kernel/armv8_deprecated.c8
-rw-r--r--arch/arm64/kernel/cpufeature.c20
2 files changed, 27 insertions, 1 deletions
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index 78d56bf..bcee7ab 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -14,6 +14,8 @@
#include <linux/slab.h>
#include <linux/sysctl.h>
+#include <asm/alternative.h>
+#include <asm/cpufeature.h>
#include <asm/insn.h>
#include <asm/opcodes.h>
#include <asm/sysreg.h>
@@ -280,6 +282,8 @@ static void register_insn_emulation_sysctl(struct ctl_table *table)
*/
#define __user_swpX_asm(data, addr, res, temp, B) \
__asm__ __volatile__( \
+ ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, \
+ CONFIG_ARM64_PAN) \
" mov %w2, %w1\n" \
"0: ldxr"B" %w1, [%3]\n" \
"1: stxr"B" %w0, %w2, [%3]\n" \
@@ -295,7 +299,9 @@ static void register_insn_emulation_sysctl(struct ctl_table *table)
" .align 3\n" \
" .quad 0b, 3b\n" \
" .quad 1b, 3b\n" \
- " .popsection" \
+ " .popsection\n" \
+ ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, \
+ CONFIG_ARM64_PAN) \
: "=&r" (res), "+r" (data), "=&r" (temp) \
: "r" (addr), "i" (-EAGAIN), "i" (-EFAULT) \
: "memory")
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 74fd0f7..978fa16 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -21,6 +21,7 @@
#include <linux/types.h>
#include <asm/cpu.h>
#include <asm/cpufeature.h>
+#include <asm/processor.h>
static bool
feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry)
@@ -39,6 +40,15 @@ has_id_aa64pfr0_feature(const struct arm64_cpu_capabilities *entry)
return feature_matches(val, entry);
}
+static bool __maybe_unused
+has_id_aa64mmfr1_feature(const struct arm64_cpu_capabilities *entry)
+{
+ u64 val;
+
+ val = read_cpuid(id_aa64mmfr1_el1);
+ return feature_matches(val, entry);
+}
+
static const struct arm64_cpu_capabilities arm64_features[] = {
{
.desc = "GIC system register CPU interface",
@@ -47,6 +57,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.field_pos = 24,
.min_field_value = 1,
},
+#ifdef CONFIG_ARM64_PAN
+ {
+ .desc = "Privileged Access Never",
+ .capability = ARM64_HAS_PAN,
+ .matches = has_id_aa64mmfr1_feature,
+ .field_pos = 20,
+ .min_field_value = 1,
+ .enable = cpu_enable_pan,
+ },
+#endif /* CONFIG_ARM64_PAN */
{},
};