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-rw-r--r--arch/arm64/mm/Makefile3
-rw-r--r--arch/arm64/mm/context.c105
-rw-r--r--arch/arm64/mm/copypage.c25
-rw-r--r--arch/arm64/mm/extable.c4
-rw-r--r--arch/arm64/mm/fault.c13
-rw-r--r--arch/arm64/mm/mmu.c20
-rw-r--r--arch/arm64/mm/mteswap.c83
-rw-r--r--arch/arm64/mm/numa.c8
-rw-r--r--arch/arm64/mm/pageattr.c1
-rw-r--r--arch/arm64/mm/proc.S32
-rw-r--r--arch/arm64/mm/ptdump.c (renamed from arch/arm64/mm/dump.c)6
11 files changed, 275 insertions, 25 deletions
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
index d91030f0ffee..5ead3c3de3b6 100644
--- a/arch/arm64/mm/Makefile
+++ b/arch/arm64/mm/Makefile
@@ -4,10 +4,11 @@ obj-y := dma-mapping.o extable.o fault.o init.o \
ioremap.o mmap.o pgd.o mmu.o \
context.o proc.o pageattr.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
-obj-$(CONFIG_PTDUMP_CORE) += dump.o
+obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
obj-$(CONFIG_PTDUMP_DEBUGFS) += ptdump_debugfs.o
obj-$(CONFIG_NUMA) += numa.o
obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
+obj-$(CONFIG_ARM64_MTE) += mteswap.o
KASAN_SANITIZE_physaddr.o += n
obj-$(CONFIG_KASAN) += kasan_init.o
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index 9b11c096a042..001737a8f309 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -27,6 +27,10 @@ static DEFINE_PER_CPU(atomic64_t, active_asids);
static DEFINE_PER_CPU(u64, reserved_asids);
static cpumask_t tlb_flush_pending;
+static unsigned long max_pinned_asids;
+static unsigned long nr_pinned_asids;
+static unsigned long *pinned_asid_map;
+
#define ASID_MASK (~GENMASK(asid_bits - 1, 0))
#define ASID_FIRST_VERSION (1UL << asid_bits)
@@ -72,7 +76,7 @@ void verify_cpu_asid_bits(void)
}
}
-static void set_kpti_asid_bits(void)
+static void set_kpti_asid_bits(unsigned long *map)
{
unsigned int len = BITS_TO_LONGS(NUM_USER_ASIDS) * sizeof(unsigned long);
/*
@@ -81,13 +85,15 @@ static void set_kpti_asid_bits(void)
* is set, then the ASID will map only userspace. Thus
* mark even as reserved for kernel.
*/
- memset(asid_map, 0xaa, len);
+ memset(map, 0xaa, len);
}
static void set_reserved_asid_bits(void)
{
- if (arm64_kernel_unmapped_at_el0())
- set_kpti_asid_bits();
+ if (pinned_asid_map)
+ bitmap_copy(asid_map, pinned_asid_map, NUM_USER_ASIDS);
+ else if (arm64_kernel_unmapped_at_el0())
+ set_kpti_asid_bits(asid_map);
else
bitmap_clear(asid_map, 0, NUM_USER_ASIDS);
}
@@ -166,6 +172,14 @@ static u64 new_context(struct mm_struct *mm)
return newasid;
/*
+ * If it is pinned, we can keep using it. Note that reserved
+ * takes priority, because even if it is also pinned, we need to
+ * update the generation into the reserved_asids.
+ */
+ if (refcount_read(&mm->context.pinned))
+ return newasid;
+
+ /*
* We had a valid ASID in a previous life, so try to re-use
* it if possible.
*/
@@ -256,6 +270,71 @@ switch_mm_fastpath:
cpu_switch_mm(mm->pgd, mm);
}
+unsigned long arm64_mm_context_get(struct mm_struct *mm)
+{
+ unsigned long flags;
+ u64 asid;
+
+ if (!pinned_asid_map)
+ return 0;
+
+ raw_spin_lock_irqsave(&cpu_asid_lock, flags);
+
+ asid = atomic64_read(&mm->context.id);
+
+ if (refcount_inc_not_zero(&mm->context.pinned))
+ goto out_unlock;
+
+ if (nr_pinned_asids >= max_pinned_asids) {
+ asid = 0;
+ goto out_unlock;
+ }
+
+ if (!asid_gen_match(asid)) {
+ /*
+ * We went through one or more rollover since that ASID was
+ * used. Ensure that it is still valid, or generate a new one.
+ */
+ asid = new_context(mm);
+ atomic64_set(&mm->context.id, asid);
+ }
+
+ nr_pinned_asids++;
+ __set_bit(asid2idx(asid), pinned_asid_map);
+ refcount_set(&mm->context.pinned, 1);
+
+out_unlock:
+ raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
+
+ asid &= ~ASID_MASK;
+
+ /* Set the equivalent of USER_ASID_BIT */
+ if (asid && arm64_kernel_unmapped_at_el0())
+ asid |= 1;
+
+ return asid;
+}
+EXPORT_SYMBOL_GPL(arm64_mm_context_get);
+
+void arm64_mm_context_put(struct mm_struct *mm)
+{
+ unsigned long flags;
+ u64 asid = atomic64_read(&mm->context.id);
+
+ if (!pinned_asid_map)
+ return;
+
+ raw_spin_lock_irqsave(&cpu_asid_lock, flags);
+
+ if (refcount_dec_and_test(&mm->context.pinned)) {
+ __clear_bit(asid2idx(asid), pinned_asid_map);
+ nr_pinned_asids--;
+ }
+
+ raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
+}
+EXPORT_SYMBOL_GPL(arm64_mm_context_put);
+
/* Errata workaround post TTBRx_EL1 update. */
asmlinkage void post_ttbr_update_workaround(void)
{
@@ -296,8 +375,11 @@ static int asids_update_limit(void)
{
unsigned long num_available_asids = NUM_USER_ASIDS;
- if (arm64_kernel_unmapped_at_el0())
+ if (arm64_kernel_unmapped_at_el0()) {
num_available_asids /= 2;
+ if (pinned_asid_map)
+ set_kpti_asid_bits(pinned_asid_map);
+ }
/*
* Expect allocation after rollover to fail if we don't have at least
* one more ASID than CPUs. ASID #0 is reserved for init_mm.
@@ -305,6 +387,13 @@ static int asids_update_limit(void)
WARN_ON(num_available_asids - 1 <= num_possible_cpus());
pr_info("ASID allocator initialised with %lu entries\n",
num_available_asids);
+
+ /*
+ * There must always be an ASID available after rollover. Ensure that,
+ * even if all CPUs have a reserved ASID and the maximum number of ASIDs
+ * are pinned, there still is at least one empty slot in the ASID map.
+ */
+ max_pinned_asids = num_available_asids - num_possible_cpus() - 2;
return 0;
}
arch_initcall(asids_update_limit);
@@ -319,13 +408,17 @@ static int asids_init(void)
panic("Failed to allocate bitmap for %lu ASIDs\n",
NUM_USER_ASIDS);
+ pinned_asid_map = kcalloc(BITS_TO_LONGS(NUM_USER_ASIDS),
+ sizeof(*pinned_asid_map), GFP_KERNEL);
+ nr_pinned_asids = 0;
+
/*
* We cannot call set_reserved_asid_bits() here because CPU
* caps are not finalized yet, so it is safer to assume KPTI
* and reserve kernel ASID's from beginning.
*/
if (IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0))
- set_kpti_asid_bits();
+ set_kpti_asid_bits(asid_map);
return 0;
}
early_initcall(asids_init);
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index 2ee7b73433a5..70a71f38b6a9 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -6,21 +6,32 @@
* Copyright (C) 2012 ARM Ltd.
*/
+#include <linux/bitops.h>
#include <linux/mm.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
+#include <asm/cpufeature.h>
+#include <asm/mte.h>
-void __cpu_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
+void copy_highpage(struct page *to, struct page *from)
{
- struct page *page = virt_to_page(kto);
+ struct page *kto = page_address(to);
+ struct page *kfrom = page_address(from);
+
copy_page(kto, kfrom);
- flush_dcache_page(page);
+
+ if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
+ set_bit(PG_mte_tagged, &to->flags);
+ mte_copy_page_tags(kto, kfrom);
+ }
}
-EXPORT_SYMBOL_GPL(__cpu_copy_user_page);
+EXPORT_SYMBOL(copy_highpage);
-void __cpu_clear_user_page(void *kaddr, unsigned long vaddr)
+void copy_user_highpage(struct page *to, struct page *from,
+ unsigned long vaddr, struct vm_area_struct *vma)
{
- clear_page(kaddr);
+ copy_highpage(to, from);
+ flush_dcache_page(to);
}
-EXPORT_SYMBOL_GPL(__cpu_clear_user_page);
+EXPORT_SYMBOL_GPL(copy_user_highpage);
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
index eee1732ab6cd..aa0060178343 100644
--- a/arch/arm64/mm/extable.c
+++ b/arch/arm64/mm/extable.c
@@ -14,9 +14,7 @@ int fixup_exception(struct pt_regs *regs)
if (!fixup)
return 0;
- if (IS_ENABLED(CONFIG_BPF_JIT) &&
- regs->pc >= BPF_JIT_REGION_START &&
- regs->pc < BPF_JIT_REGION_END)
+ if (in_bpf_jit(regs))
return arm64_bpf_fixup_exception(fixup, regs);
regs->pc = (unsigned long)&fixup->fixup + fixup->fixup;
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index f07333e86c2f..94c99c1c19e3 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -218,7 +218,9 @@ int ptep_set_access_flags(struct vm_area_struct *vma,
pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
} while (pteval != old_pteval);
- flush_tlb_fix_spurious_fault(vma, address);
+ /* Invalidate a stale read-only entry */
+ if (dirty)
+ flush_tlb_page(vma, address);
return 1;
}
@@ -641,6 +643,13 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
return 0;
}
+static int do_tag_check_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
+{
+ do_bad_area(addr, esr, regs);
+ return 0;
+}
+
static const struct fault_info fault_info[] = {
{ do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" },
{ do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" },
@@ -659,7 +668,7 @@ static const struct fault_info fault_info[] = {
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
{ do_sea, SIGBUS, BUS_OBJERR, "synchronous external abort" },
- { do_bad, SIGKILL, SI_KERNEL, "unknown 17" },
+ { do_tag_check_fault, SIGSEGV, SEGV_MTESERR, "synchronous tag check fault" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 18" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 19" },
{ do_sea, SIGKILL, SI_KERNEL, "level 0 (translation table walk)" },
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 75df62fea1b6..936c4762dadf 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -122,7 +122,7 @@ static bool pgattr_change_is_safe(u64 old, u64 new)
* The following mapping attributes may be updated in live
* kernel mappings without the need for break-before-make.
*/
- static const pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG;
+ pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG;
/* creating or taking down mappings is always safe */
if (old == 0 || new == 0)
@@ -136,6 +136,17 @@ static bool pgattr_change_is_safe(u64 old, u64 new)
if (old & ~new & PTE_NG)
return false;
+ /*
+ * Changing the memory type between Normal and Normal-Tagged is safe
+ * since Tagged is considered a permission attribute from the
+ * mismatched attribute aliases perspective.
+ */
+ if (((old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) ||
+ (old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)) &&
+ ((new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) ||
+ (new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)))
+ mask |= PTE_ATTRINDX_MASK;
+
return ((old ^ new) & ~mask) == 0;
}
@@ -491,7 +502,12 @@ static void __init map_mem(pgd_t *pgdp)
if (memblock_is_nomap(reg))
continue;
- __map_memblock(pgdp, start, end, PAGE_KERNEL, flags);
+ /*
+ * The linear map must allow allocation tags reading/writing
+ * if MTE is present. Otherwise, it has the same attributes as
+ * PAGE_KERNEL.
+ */
+ __map_memblock(pgdp, start, end, PAGE_KERNEL_TAGGED, flags);
}
/*
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c
new file mode 100644
index 000000000000..c52c1847079c
--- /dev/null
+++ b/arch/arm64/mm/mteswap.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/pagemap.h>
+#include <linux/xarray.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <asm/mte.h>
+
+static DEFINE_XARRAY(mte_pages);
+
+void *mte_allocate_tag_storage(void)
+{
+ /* tags granule is 16 bytes, 2 tags stored per byte */
+ return kmalloc(PAGE_SIZE / 16 / 2, GFP_KERNEL);
+}
+
+void mte_free_tag_storage(char *storage)
+{
+ kfree(storage);
+}
+
+int mte_save_tags(struct page *page)
+{
+ void *tag_storage, *ret;
+
+ if (!test_bit(PG_mte_tagged, &page->flags))
+ return 0;
+
+ tag_storage = mte_allocate_tag_storage();
+ if (!tag_storage)
+ return -ENOMEM;
+
+ mte_save_page_tags(page_address(page), tag_storage);
+
+ /* page_private contains the swap entry.val set in do_swap_page */
+ ret = xa_store(&mte_pages, page_private(page), tag_storage, GFP_KERNEL);
+ if (WARN(xa_is_err(ret), "Failed to store MTE tags")) {
+ mte_free_tag_storage(tag_storage);
+ return xa_err(ret);
+ } else if (ret) {
+ /* Entry is being replaced, free the old entry */
+ mte_free_tag_storage(ret);
+ }
+
+ return 0;
+}
+
+bool mte_restore_tags(swp_entry_t entry, struct page *page)
+{
+ void *tags = xa_load(&mte_pages, entry.val);
+
+ if (!tags)
+ return false;
+
+ mte_restore_page_tags(page_address(page), tags);
+
+ return true;
+}
+
+void mte_invalidate_tags(int type, pgoff_t offset)
+{
+ swp_entry_t entry = swp_entry(type, offset);
+ void *tags = xa_erase(&mte_pages, entry.val);
+
+ mte_free_tag_storage(tags);
+}
+
+void mte_invalidate_tags_area(int type)
+{
+ swp_entry_t entry = swp_entry(type, 0);
+ swp_entry_t last_entry = swp_entry(type + 1, 0);
+ void *tags;
+
+ XA_STATE(xa_state, &mte_pages, entry.val);
+
+ xa_lock(&mte_pages);
+ xas_for_each(&xa_state, tags, last_entry.val - 1) {
+ __xa_erase(&mte_pages, xa_state.xa_index);
+ mte_free_tag_storage(tags);
+ }
+ xa_unlock(&mte_pages);
+}
diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
index 73f8b49d485c..676deb220b99 100644
--- a/arch/arm64/mm/numa.c
+++ b/arch/arm64/mm/numa.c
@@ -46,7 +46,11 @@ EXPORT_SYMBOL(node_to_cpumask_map);
*/
const struct cpumask *cpumask_of_node(int node)
{
- if (WARN_ON(node >= nr_node_ids))
+
+ if (node == NUMA_NO_NODE)
+ return cpu_all_mask;
+
+ if (WARN_ON(node < 0 || node >= nr_node_ids))
return cpu_none_mask;
if (WARN_ON(node_to_cpumask_map[node] == NULL))
@@ -448,7 +452,7 @@ static int __init dummy_numa_init(void)
* arm64_numa_init() - Initialize NUMA
*
* Try each configured NUMA initialization method until one succeeds. The
- * last fallback is dummy single node config encomapssing whole memory.
+ * last fallback is dummy single node config encompassing whole memory.
*/
void __init arm64_numa_init(void)
{
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 23f648c2a199..1b94f5b82654 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -8,6 +8,7 @@
#include <linux/sched.h>
#include <linux/vmalloc.h>
+#include <asm/cacheflush.h>
#include <asm/set_memory.h>
#include <asm/tlbflush.h>
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 796e47a571e6..23c326a06b2d 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -18,6 +18,7 @@
#include <asm/cpufeature.h>
#include <asm/alternative.h>
#include <asm/smp.h>
+#include <asm/sysreg.h>
#ifdef CONFIG_ARM64_64K_PAGES
#define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K
@@ -44,14 +45,18 @@
#define TCR_KASAN_FLAGS 0
#endif
-/* Default MAIR_EL1 */
+/*
+ * Default MAIR_EL1. MT_NORMAL_TAGGED is initially mapped as Normal memory and
+ * changed during __cpu_setup to Normal Tagged if the system supports MTE.
+ */
#define MAIR_EL1_SET \
(MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRnE, MT_DEVICE_nGnRnE) | \
MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRE, MT_DEVICE_nGnRE) | \
MAIR_ATTRIDX(MAIR_ATTR_DEVICE_GRE, MT_DEVICE_GRE) | \
MAIR_ATTRIDX(MAIR_ATTR_NORMAL_NC, MT_NORMAL_NC) | \
MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL) | \
- MAIR_ATTRIDX(MAIR_ATTR_NORMAL_WT, MT_NORMAL_WT))
+ MAIR_ATTRIDX(MAIR_ATTR_NORMAL_WT, MT_NORMAL_WT) | \
+ MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL_TAGGED))
#ifdef CONFIG_CPU_PM
/**
@@ -421,6 +426,29 @@ SYM_FUNC_START(__cpu_setup)
* Memory region attributes
*/
mov_q x5, MAIR_EL1_SET
+#ifdef CONFIG_ARM64_MTE
+ /*
+ * Update MAIR_EL1, GCR_EL1 and TFSR*_EL1 if MTE is supported
+ * (ID_AA64PFR1_EL1[11:8] > 1).
+ */
+ mrs x10, ID_AA64PFR1_EL1
+ ubfx x10, x10, #ID_AA64PFR1_MTE_SHIFT, #4
+ cmp x10, #ID_AA64PFR1_MTE
+ b.lt 1f
+
+ /* Normal Tagged memory type at the corresponding MAIR index */
+ mov x10, #MAIR_ATTR_NORMAL_TAGGED
+ bfi x5, x10, #(8 * MT_NORMAL_TAGGED), #8
+
+ /* initialize GCR_EL1: all non-zero tags excluded by default */
+ mov x10, #(SYS_GCR_EL1_RRND | SYS_GCR_EL1_EXCL_MASK)
+ msr_s SYS_GCR_EL1, x10
+
+ /* clear any pending tag check faults in TFSR*_EL1 */
+ msr_s SYS_TFSR_EL1, xzr
+ msr_s SYS_TFSRE0_EL1, xzr
+1:
+#endif
msr mair_el1, x5
/*
* Set/prepare TCR and TTBR. We use 512GB (39-bit) address range for
diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/ptdump.c
index 0b8da1cc1c07..807dc634bbd2 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/ptdump.c
@@ -41,6 +41,8 @@ static struct addr_marker address_markers[] = {
{ 0 /* KASAN_SHADOW_START */, "Kasan shadow start" },
{ KASAN_SHADOW_END, "Kasan shadow end" },
#endif
+ { BPF_JIT_REGION_START, "BPF start" },
+ { BPF_JIT_REGION_END, "BPF end" },
{ MODULES_VADDR, "Modules start" },
{ MODULES_END, "Modules end" },
{ VMALLOC_START, "vmalloc() area" },
@@ -169,6 +171,10 @@ static const struct prot_bits pte_bits[] = {
.mask = PTE_ATTRINDX_MASK,
.val = PTE_ATTRINDX(MT_NORMAL),
.set = "MEM/NORMAL",
+ }, {
+ .mask = PTE_ATTRINDX_MASK,
+ .val = PTE_ATTRINDX(MT_NORMAL_TAGGED),
+ .set = "MEM/NORMAL-TAGGED",
}
};