From: Ard Biesheuvel <ardb@xxxxxxxxxx>
When FEAT_LPA{,2} are not implemented, the ID_AA64MMFR0_EL1.PARange and
TCR.IPS values corresponding with 52-bit physical addressing are
reserved.
Setting the TCR.IPS field to 0b110 (52-bit physical addressing) has side
effects, such as how the TTBRn_ELx.BADDR fields are interpreted, and so
it is important that disabling FEAT_LPA2 (by overriding the
ID_AA64MMFR0.TGran fields) also presents a PARange field consistent with
that.
So limit the field to 48 bits unless LPA2 is enabled, and update
existing references to use the override consistently.
Fixes: 352b0395b505 ("arm64: Enable 52-bit virtual addressing for 4k and 16k granule configs")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/arm64/include/asm/assembler.h | 5 +++++
arch/arm64/kernel/cpufeature.c | 2 +-
arch/arm64/kernel/pi/idreg-override.c | 9 +++++++++
arch/arm64/kernel/pi/map_kernel.c | 6 ++++++
arch/arm64/mm/init.c | 7 ++++++-
5 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 3d8d534a7a77..ad63457a05c5 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -343,6 +343,11 @@ alternative_cb_end
// Narrow PARange to fit the PS field in TCR_ELx
ubfx \tmp0, \tmp0, #ID_AA64MMFR0_EL1_PARANGE_SHIFT, #3
mov \tmp1, #ID_AA64MMFR0_EL1_PARANGE_MAX
+#ifdef CONFIG_ARM64_LPA2
+alternative_if_not ARM64_HAS_VA52
+ mov \tmp1, #ID_AA64MMFR0_EL1_PARANGE_48
+alternative_else_nop_endif
+#endif
cmp \tmp0, \tmp1
csel \tmp0, \tmp1, \tmp0, hi
bfi \tcr, \tmp0, \pos, #3
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6ce71f444ed8..f8cb8a6ab98a 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -3478,7 +3478,7 @@ static void verify_hyp_capabilities(void)
return;
safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
- mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
+ mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
/* Verify VMID bits */
diff --git a/arch/arm64/kernel/pi/idreg-override.c b/arch/arm64/kernel/pi/idreg-override.c
index 22159251eb3a..c6b185b885f7 100644
--- a/arch/arm64/kernel/pi/idreg-override.c
+++ b/arch/arm64/kernel/pi/idreg-override.c
@@ -83,6 +83,15 @@ static bool __init mmfr2_varange_filter(u64 val)
id_aa64mmfr0_override.val |=
(ID_AA64MMFR0_EL1_TGRAN_LPA2 - 1) << ID_AA64MMFR0_EL1_TGRAN_SHIFT;
id_aa64mmfr0_override.mask |= 0xfU << ID_AA64MMFR0_EL1_TGRAN_SHIFT;
+
+ /*
+ * Override PARange to 48 bits - the override will just be
+ * ignored if the actual PARange is smaller, but this is
+ * unlikely to be the case for LPA2 capable silicon.
+ */
+ id_aa64mmfr0_override.val |=
+ ID_AA64MMFR0_EL1_PARANGE_48 << ID_AA64MMFR0_EL1_PARANGE_SHIFT;
+ id_aa64mmfr0_override.mask |= 0xfU << ID_AA64MMFR0_EL1_PARANGE_SHIFT;
}
#endif
return true;
diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c
index f374a3e5a5fe..e57b043f324b 100644
--- a/arch/arm64/kernel/pi/map_kernel.c
+++ b/arch/arm64/kernel/pi/map_kernel.c
@@ -136,6 +136,12 @@ static void noinline __section(".idmap.text") set_ttbr0_for_lpa2(u64 ttbr)
{
u64 sctlr = read_sysreg(sctlr_el1);
u64 tcr = read_sysreg(tcr_el1) | TCR_DS;
+ u64 mmfr0 = read_sysreg(id_aa64mmfr0_el1);
+ u64 parange = cpuid_feature_extract_unsigned_field(mmfr0,
+ ID_AA64MMFR0_EL1_PARANGE_SHIFT);
+
+ tcr &= ~TCR_IPS_MASK;
+ tcr |= parange << TCR_IPS_SHIFT;
asm(" msr sctlr_el1, %0 ;"
" isb ;"
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index d21f67d67cf5..2b2289d55eaa 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -280,7 +280,12 @@ void __init arm64_memblock_init(void)
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
extern u16 memstart_offset_seed;
- u64 mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
+
+ /*
+ * Use the sanitised version of id_aa64mmfr0_el1 so that linear
+ * map randomization can be enabled by shrinking the IPA space.
+ */
+ u64 mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
int parange = cpuid_feature_extract_unsigned_field(
mmfr0, ID_AA64MMFR0_EL1_PARANGE_SHIFT);
s64 range = linear_region_size -
--
2.47.1.613.gc27f4b7a9f-goog
