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authorLinus Torvalds <torvalds@linux-foundation.org>2019-01-11 12:25:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-11 12:25:40 -0800
commitc3405d689974555532c12a4f3a5e72dedc660c0b (patch)
tree31b1c24faefa8dc26c1b04104a19045acbedc3dd
parentf87092c4337fc064b52bfad1df499a5b82f6d088 (diff)
parent279667212ab2a4f36c3b0347657ddcc11f9cfa25 (diff)
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon: "Another handful of arm64 fixes here. Most of the complication comes from improving our kpti code to avoid lengthy pauses (30+ seconds) during boot when we rewrite the page tables. There are also a couple of IORT fixes that came in via Lorenzo. Summary: - Don't error in kexec_file_load if kaslr-seed is missing in device-tree - Fix incorrect argument type passed to iort_match_node_callback() - Fix IORT build failure when CONFIG_IOMMU_API=n - Fix kpti performance regression with new rodata default option - Typo fix" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: kexec_file: return successfully even if kaslr-seed doesn't exist ACPI/IORT: Fix rc_dma_get_range() arm64: kpti: Avoid rewriting early page tables when KASLR is enabled arm64: asm-prototypes: Fix fat-fingered typo in comment ACPI/IORT: Fix build when CONFIG_IOMMU_API=n
-rw-r--r--arch/arm64/include/asm/asm-prototypes.h2
-rw-r--r--arch/arm64/include/asm/mmu.h41
-rw-r--r--arch/arm64/include/asm/pgtable-prot.h4
-rw-r--r--arch/arm64/kernel/cpu_errata.c2
-rw-r--r--arch/arm64/kernel/cpufeature.c9
-rw-r--r--arch/arm64/kernel/head.S1
-rw-r--r--arch/arm64/kernel/machine_kexec_file.c4
-rw-r--r--drivers/acpi/arm64/iort.c5
8 files changed, 59 insertions, 9 deletions
diff --git a/arch/arm64/include/asm/asm-prototypes.h b/arch/arm64/include/asm/asm-prototypes.h
index 2173ad32d550..1c9a3a0c5fa5 100644
--- a/arch/arm64/include/asm/asm-prototypes.h
+++ b/arch/arm64/include/asm/asm-prototypes.h
@@ -2,7 +2,7 @@
#ifndef __ASM_PROTOTYPES_H
#define __ASM_PROTOTYPES_H
/*
- * CONFIG_MODEVERIONS requires a C declaration to generate the appropriate CRC
+ * CONFIG_MODVERSIONS requires a C declaration to generate the appropriate CRC
* for each symbol. Since commit:
*
* 4efca4ed05cbdfd1 ("kbuild: modversions for EXPORT_SYMBOL() for asm")
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index 7689c7aa1d77..ac352accb3d9 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -16,6 +16,8 @@
#ifndef __ASM_MMU_H
#define __ASM_MMU_H
+#include <asm/cputype.h>
+
#define MMCF_AARCH32 0x1 /* mm context flag for AArch32 executables */
#define USER_ASID_BIT 48
#define USER_ASID_FLAG (UL(1) << USER_ASID_BIT)
@@ -44,6 +46,45 @@ static inline bool arm64_kernel_unmapped_at_el0(void)
cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0);
}
+static inline bool arm64_kernel_use_ng_mappings(void)
+{
+ bool tx1_bug;
+
+ /* What's a kpti? Use global mappings if we don't know. */
+ if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0))
+ return false;
+
+ /*
+ * Note: this function is called before the CPU capabilities have
+ * been configured, so our early mappings will be global. If we
+ * later determine that kpti is required, then
+ * kpti_install_ng_mappings() will make them non-global.
+ */
+ if (!IS_ENABLED(CONFIG_RANDOMIZE_BASE))
+ return arm64_kernel_unmapped_at_el0();
+
+ /*
+ * KASLR is enabled so we're going to be enabling kpti on non-broken
+ * CPUs regardless of their susceptibility to Meltdown. Rather
+ * than force everybody to go through the G -> nG dance later on,
+ * just put down non-global mappings from the beginning.
+ */
+ if (!IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456)) {
+ tx1_bug = false;
+#ifndef MODULE
+ } else if (!static_branch_likely(&arm64_const_caps_ready)) {
+ extern const struct midr_range cavium_erratum_27456_cpus[];
+
+ tx1_bug = is_midr_in_range_list(read_cpuid_id(),
+ cavium_erratum_27456_cpus);
+#endif
+ } else {
+ tx1_bug = __cpus_have_const_cap(ARM64_WORKAROUND_CAVIUM_27456);
+ }
+
+ return !tx1_bug && kaslr_offset() > 0;
+}
+
typedef void (*bp_hardening_cb_t)(void);
struct bp_hardening_data {
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index 78b942c1bea4..986e41c4c32b 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -37,8 +37,8 @@
#define _PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
#define _PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
-#define PTE_MAYBE_NG (arm64_kernel_unmapped_at_el0() ? PTE_NG : 0)
-#define PMD_MAYBE_NG (arm64_kernel_unmapped_at_el0() ? PMD_SECT_NG : 0)
+#define PTE_MAYBE_NG (arm64_kernel_use_ng_mappings() ? PTE_NG : 0)
+#define PMD_MAYBE_NG (arm64_kernel_use_ng_mappings() ? PMD_SECT_NG : 0)
#define PROT_DEFAULT (_PROT_DEFAULT | PTE_MAYBE_NG)
#define PROT_SECT_DEFAULT (_PROT_SECT_DEFAULT | PMD_MAYBE_NG)
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 09ac548c9d44..9950bb0cbd52 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -553,7 +553,7 @@ static const struct midr_range arm64_repeat_tlbi_cpus[] = {
#endif
#ifdef CONFIG_CAVIUM_ERRATUM_27456
-static const struct midr_range cavium_erratum_27456_cpus[] = {
+const struct midr_range cavium_erratum_27456_cpus[] = {
/* Cavium ThunderX, T88 pass 1.x - 2.1 */
MIDR_RANGE(MIDR_THUNDERX, 0, 0, 1, 1),
/* Cavium ThunderX, T81 pass 1.0 */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 4f272399de89..f6d84e2c92fe 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -983,7 +983,7 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry,
/* Useful for KASLR robustness */
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
- return true;
+ return kaslr_offset() > 0;
/* Don't force KPTI for CPUs that are not vulnerable */
if (is_midr_in_range_list(read_cpuid_id(), kpti_safe_list))
@@ -1003,7 +1003,12 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused)
static bool kpti_applied = false;
int cpu = smp_processor_id();
- if (kpti_applied)
+ /*
+ * We don't need to rewrite the page-tables if either we've done
+ * it already or we have KASLR enabled and therefore have not
+ * created any global mappings at all.
+ */
+ if (kpti_applied || kaslr_offset() > 0)
return;
remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index c7213674cb24..15d79a8e5e5e 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -475,6 +475,7 @@ ENDPROC(__primary_switched)
ENTRY(kimage_vaddr)
.quad _text - TEXT_OFFSET
+EXPORT_SYMBOL(kimage_vaddr)
/*
* If we're fortunate enough to boot at EL2, ensure that the world is
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index 10e33860e47a..f2c211a6229b 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -87,7 +87,9 @@ static int setup_dtb(struct kimage *image,
/* add kaslr-seed */
ret = fdt_delprop(dtb, off, FDT_PROP_KASLR_SEED);
- if (ret && (ret != -FDT_ERR_NOTFOUND))
+ if (ret == -FDT_ERR_NOTFOUND)
+ ret = 0;
+ else if (ret)
goto out;
if (rng_is_initialized()) {
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index fdd90ffceb85..e48894e002ba 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -876,7 +876,7 @@ int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
return (resv == its->its_count) ? resv : -ENODEV;
}
#else
-static inline const struct iommu_ops *iort_fwspec_iommu_ops(struct device *dev);
+static inline const struct iommu_ops *iort_fwspec_iommu_ops(struct device *dev)
{ return NULL; }
static inline int iort_add_device_replay(const struct iommu_ops *ops,
struct device *dev)
@@ -952,9 +952,10 @@ static int rc_dma_get_range(struct device *dev, u64 *size)
{
struct acpi_iort_node *node;
struct acpi_iort_root_complex *rc;
+ struct pci_bus *pbus = to_pci_dev(dev)->bus;
node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
- iort_match_node_callback, dev);
+ iort_match_node_callback, &pbus->dev);
if (!node || node->revision < 1)
return -ENODEV;

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