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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-05 11:18:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-05 11:18:53 -0700
commitf4dd60a3d4c7656dcaa0ba2afb503528c86f913f (patch)
treeee584ae030806416e8bee7eb099fd40b67cbbe4a
parent435faf5c218a47fd6258187f62d9bb1009717896 (diff)
parentbd1de2a7aace4d1d312fb1be264b8fafdb706208 (diff)
Merge tag 'x86-mm-2020-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Ingo Molnar: "Misc changes: - Unexport various PAT primitives - Unexport per-CPU tlbstate and uninline TLB helpers" * tag 'x86-mm-2020-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/tlb/uv: Add a forward declaration for struct flush_tlb_info x86/cpu: Export native_write_cr4() only when CONFIG_LKTDM=m x86/tlb: Restrict access to tlbstate xen/privcmd: Remove unneeded asm/tlb.h include x86/tlb: Move PCID helpers where they are used x86/tlb: Uninline nmi_uaccess_okay() x86/tlb: Move cr4_set_bits_and_update_boot() to the usage site x86/tlb: Move paravirt_tlb_remove_table() to the usage site x86/tlb: Move __flush_tlb_all() out of line x86/tlb: Move flush_tlb_others() out of line x86/tlb: Move __flush_tlb_one_kernel() out of line x86/tlb: Move __flush_tlb_one_user() out of line x86/tlb: Move __flush_tlb_global() out of line x86/tlb: Move __flush_tlb() out of line x86/alternatives: Move temporary_mm helpers into C x86/cr4: Sanitize CR4.PCE update x86/cpu: Uninline CR4 accessors x86/tlb: Uninline __get_current_cr3_fast() x86/mm: Use pgprotval_t in protval_4k_2_large() and protval_large_2_4k() x86/mm: Unexport __cachemode2pte_tbl ...
-rw-r--r--arch/x86/events/core.c11
-rw-r--r--arch/x86/include/asm/memtype.h3
-rw-r--r--arch/x86/include/asm/mmu_context.h88
-rw-r--r--arch/x86/include/asm/paravirt.h12
-rw-r--r--arch/x86/include/asm/pgtable_32.h2
-rw-r--r--arch/x86/include/asm/pgtable_types.h44
-rw-r--r--arch/x86/include/asm/tlbflush.h441
-rw-r--r--arch/x86/include/asm/uv/uv.h1
-rw-r--r--arch/x86/kernel/alternative.c55
-rw-r--r--arch/x86/kernel/cpu/common.c25
-rw-r--r--arch/x86/kernel/cpu/mtrr/generic.c4
-rw-r--r--arch/x86/kernel/paravirt.c21
-rw-r--r--arch/x86/kernel/process.c11
-rw-r--r--arch/x86/mm/init.c44
-rw-r--r--arch/x86/mm/init_64.c4
-rw-r--r--arch/x86/mm/ioremap.c10
-rw-r--r--arch/x86/mm/kmmio.c2
-rw-r--r--arch/x86/mm/mem_encrypt.c2
-rw-r--r--arch/x86/mm/pat/set_memory.c7
-rw-r--r--arch/x86/mm/pgtable.c16
-rw-r--r--arch/x86/mm/pgtable_32.c2
-rw-r--r--arch/x86/mm/tlb.c384
-rw-r--r--arch/x86/platform/uv/tlb_uv.c4
-rw-r--r--drivers/xen/privcmd.c1
24 files changed, 608 insertions, 586 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 9e63ee50b19a..ea2a3d151294 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2166,11 +2166,6 @@ static int x86_pmu_event_init(struct perf_event *event)
return err;
}
-static void refresh_pce(void *ignored)
-{
- load_mm_cr4_irqsoff(this_cpu_read(cpu_tlbstate.loaded_mm));
-}
-
static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)
{
if (!(event->hw.flags & PERF_X86_EVENT_RDPMC_ALLOWED))
@@ -2189,7 +2184,7 @@ static void x86_pmu_event_mapped(struct perf_event *event, struct mm_struct *mm)
lockdep_assert_held_write(&mm->mmap_sem);
if (atomic_inc_return(&mm->context.perf_rdpmc_allowed) == 1)
- on_each_cpu_mask(mm_cpumask(mm), refresh_pce, NULL, 1);
+ on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1);
}
static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *mm)
@@ -2199,7 +2194,7 @@ static void x86_pmu_event_unmapped(struct perf_event *event, struct mm_struct *m
return;
if (atomic_dec_and_test(&mm->context.perf_rdpmc_allowed))
- on_each_cpu_mask(mm_cpumask(mm), refresh_pce, NULL, 1);
+ on_each_cpu_mask(mm_cpumask(mm), cr4_update_pce, NULL, 1);
}
static int x86_pmu_event_idx(struct perf_event *event)
@@ -2257,7 +2252,7 @@ static ssize_t set_attr_rdpmc(struct device *cdev,
else if (x86_pmu.attr_rdpmc == 2)
static_branch_dec(&rdpmc_always_available_key);
- on_each_cpu(refresh_pce, NULL, 1);
+ on_each_cpu(cr4_update_pce, NULL, 1);
x86_pmu.attr_rdpmc = val;
}
diff --git a/arch/x86/include/asm/memtype.h b/arch/x86/include/asm/memtype.h
index 9c2447b3555d..9ca760e430b9 100644
--- a/arch/x86/include/asm/memtype.h
+++ b/arch/x86/include/asm/memtype.h
@@ -24,4 +24,7 @@ extern void memtype_free_io(resource_size_t start, resource_size_t end);
extern bool pat_pfn_immune_to_uc_mtrr(unsigned long pfn);
+bool x86_has_pat_wp(void);
+enum page_cache_mode pgprot2cachemode(pgprot_t pgprot);
+
#endif /* _ASM_X86_MEMTYPE_H */
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index 4e55370e48e8..47562147e70b 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -24,21 +24,9 @@ static inline void paravirt_activate_mm(struct mm_struct *prev,
#endif /* !CONFIG_PARAVIRT_XXL */
#ifdef CONFIG_PERF_EVENTS
-
DECLARE_STATIC_KEY_FALSE(rdpmc_never_available_key);
DECLARE_STATIC_KEY_FALSE(rdpmc_always_available_key);
-
-static inline void load_mm_cr4_irqsoff(struct mm_struct *mm)
-{
- if (static_branch_unlikely(&rdpmc_always_available_key) ||
- (!static_branch_unlikely(&rdpmc_never_available_key) &&
- atomic_read(&mm->context.perf_rdpmc_allowed)))
- cr4_set_bits_irqsoff(X86_CR4_PCE);
- else
- cr4_clear_bits_irqsoff(X86_CR4_PCE);
-}
-#else
-static inline void load_mm_cr4_irqsoff(struct mm_struct *mm) {}
+void cr4_update_pce(void *ignored);
#endif
#ifdef CONFIG_MODIFY_LDT_SYSCALL
@@ -225,78 +213,6 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
return __pkru_allows_pkey(vma_pkey(vma), write);
}
-/*
- * This can be used from process context to figure out what the value of
- * CR3 is without needing to do a (slow) __read_cr3().
- *
- * It's intended to be used for code like KVM that sneakily changes CR3
- * and needs to restore it. It needs to be used very carefully.
- */
-static inline unsigned long __get_current_cr3_fast(void)
-{
- unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd,
- this_cpu_read(cpu_tlbstate.loaded_mm_asid));
-
- /* For now, be very restrictive about when this can be called. */
- VM_WARN_ON(in_nmi() || preemptible());
-
- VM_BUG_ON(cr3 != __read_cr3());
- return cr3;
-}
-
-typedef struct {
- struct mm_struct *mm;
-} temp_mm_state_t;
-
-/*
- * Using a temporary mm allows to set temporary mappings that are not accessible
- * by other CPUs. Such mappings are needed to perform sensitive memory writes
- * that override the kernel memory protections (e.g., W^X), without exposing the
- * temporary page-table mappings that are required for these write operations to
- * other CPUs. Using a temporary mm also allows to avoid TLB shootdowns when the
- * mapping is torn down.
- *
- * Context: The temporary mm needs to be used exclusively by a single core. To
- * harden security IRQs must be disabled while the temporary mm is
- * loaded, thereby preventing interrupt handler bugs from overriding
- * the kernel memory protection.
- */
-static inline temp_mm_state_t use_temporary_mm(struct mm_struct *mm)
-{
- temp_mm_state_t temp_state;
-
- lockdep_assert_irqs_disabled();
- temp_state.mm = this_cpu_read(cpu_tlbstate.loaded_mm);
- switch_mm_irqs_off(NULL, mm, current);
-
- /*
- * If breakpoints are enabled, disable them while the temporary mm is
- * used. Userspace might set up watchpoints on addresses that are used
- * in the temporary mm, which would lead to wrong signals being sent or
- * crashes.
- *
- * Note that breakpoints are not disabled selectively, which also causes
- * kernel breakpoints (e.g., perf's) to be disabled. This might be
- * undesirable, but still seems reasonable as the code that runs in the
- * temporary mm should be short.
- */
- if (hw_breakpoint_active())
- hw_breakpoint_disable();
-
- return temp_state;
-}
-
-static inline void unuse_temporary_mm(temp_mm_state_t prev_state)
-{
- lockdep_assert_irqs_disabled();
- switch_mm_irqs_off(NULL, prev_state.mm, current);
-
- /*
- * Restore the breakpoints if they were disabled before the temporary mm
- * was loaded.
- */
- if (hw_breakpoint_active())
- hw_breakpoint_restore();
-}
+unsigned long __get_current_cr3_fast(void);
#endif /* _ASM_X86_MMU_CONTEXT_H */
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 694d8daf4983..5ca5d297df75 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -47,7 +47,13 @@ static inline void slow_down_io(void)
#endif
}
-static inline void __flush_tlb(void)
+void native_flush_tlb_local(void);
+void native_flush_tlb_global(void);
+void native_flush_tlb_one_user(unsigned long addr);
+void native_flush_tlb_others(const struct cpumask *cpumask,
+ const struct flush_tlb_info *info);
+
+static inline void __flush_tlb_local(void)
{
PVOP_VCALL0(mmu.flush_tlb_user);
}
@@ -62,8 +68,8 @@ static inline void __flush_tlb_one_user(unsigned long addr)
PVOP_VCALL1(mmu.flush_tlb_one_user, addr);
}
-static inline void flush_tlb_others(const struct cpumask *cpumask,
- const struct flush_tlb_info *info)
+static inline void __flush_tlb_others(const struct cpumask *cpumask,
+ const struct flush_tlb_info *info)
{
PVOP_VCALL2(mmu.flush_tlb_others, cpumask, info);
}
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index be7b19646897..82dc0d8464fa 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -60,7 +60,7 @@ void sync_initial_page_table(void);
#define kpte_clear_flush(ptep, vaddr) \
do { \
pte_clear(&init_mm, (vaddr), (ptep)); \
- __flush_tlb_one_kernel((vaddr)); \
+ flush_tlb_one_kernel((vaddr)); \
} while (0)
#endif /* !__ASSEMBLY__ */
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 2e7c442cc618..2da1f95b88d7 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -471,9 +471,6 @@ static inline pteval_t pte_flags(pte_t pte)
return native_pte_val(pte) & PTE_FLAGS_MASK;
}
-extern uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM];
-extern uint8_t __pte2cachemode_tbl[8];
-
#define __pte2cm_idx(cb) \
((((cb) >> (_PAGE_BIT_PAT - 2)) & 4) | \
(((cb) >> (_PAGE_BIT_PCD - 1)) & 2) | \
@@ -483,43 +480,26 @@ extern uint8_t __pte2cachemode_tbl[8];
(((i) & 2) << (_PAGE_BIT_PCD - 1)) | \
(((i) & 1) << _PAGE_BIT_PWT))
-static inline unsigned long cachemode2protval(enum page_cache_mode pcm)
+unsigned long cachemode2protval(enum page_cache_mode pcm);
+
+static inline pgprotval_t protval_4k_2_large(pgprotval_t val)
{
- if (likely(pcm == 0))
- return 0;
- return __cachemode2pte_tbl[pcm];
+ return (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
+ ((val & _PAGE_PAT) << (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));
}
-static inline pgprot_t cachemode2pgprot(enum page_cache_mode pcm)
+static inline pgprot_t pgprot_4k_2_large(pgprot_t pgprot)
{
- return __pgprot(cachemode2protval(pcm));
+ return __pgprot(protval_4k_2_large(pgprot_val(pgprot)));
}
-static inline enum page_cache_mode pgprot2cachemode(pgprot_t pgprot)
+static inline pgprotval_t protval_large_2_4k(pgprotval_t val)
{
- unsigned long masked;
-
- masked = pgprot_val(pgprot) & _PAGE_CACHE_MASK;
- if (likely(masked == 0))
- return 0;
- return __pte2cachemode_tbl[__pte2cm_idx(masked)];
-}
-static inline pgprot_t pgprot_4k_2_large(pgprot_t pgprot)
-{
- pgprotval_t val = pgprot_val(pgprot);
- pgprot_t new;
-
- pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
- ((val & _PAGE_PAT) << (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));
- return new;
+ return (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
+ ((val & _PAGE_PAT_LARGE) >>
+ (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));
}
static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot)
{
- pgprotval_t val = pgprot_val(pgprot);
- pgprot_t new;
-
- pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) |
- ((val & _PAGE_PAT_LARGE) >>
- (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT));
- return new;
+ return __pgprot(protval_large_2_4k(pgprot_val(pgprot)));
}
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 6f66d841262d..8c87a2e0b660 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -13,140 +13,51 @@
#include <asm/pti.h>
#include <asm/processor-flags.h>
-/*
- * The x86 feature is called PCID (Process Context IDentifier). It is similar
- * to what is traditionally called ASID on the RISC processors.
- *
- * We don't use the traditional ASID implementation, where each process/mm gets
- * its own ASID and flush/restart when we run out of ASID space.
- *
- * Instead we have a small per-cpu array of ASIDs and cache the last few mm's
- * that came by on this CPU, allowing cheaper switch_mm between processes on
- * this CPU.
- *
- * We end up with different spaces for different things. To avoid confusion we
- * use different names for each of them:
- *
- * ASID - [0, TLB_NR_DYN_ASIDS-1]
- * the canonical identifier for an mm
- *
- * kPCID - [1, TLB_NR_DYN_ASIDS]
- * the value we write into the PCID part of CR3; corresponds to the
- * ASID+1, because PCID 0 is special.
- *
- * uPCID - [2048 + 1, 2048 + TLB_NR_DYN_ASIDS]
- * for KPTI each mm has two address spaces and thus needs two
- * PCID values, but we can still do with a single ASID denomination
- * for each mm. Corresponds to kPCID + 2048.
- *
- */
-
-/* There are 12 bits of space for ASIDS in CR3 */
-#define CR3_HW_ASID_BITS 12
-
-/*
- * When enabled, PAGE_TABLE_ISOLATION consumes a single bit for
- * user/kernel switches
- */
-#ifdef CONFIG_PAGE_TABLE_ISOLATION
-# define PTI_CONSUMED_PCID_BITS 1
-#else
-# define PTI_CONSUMED_PCID_BITS 0
-#endif
+void __flush_tlb_all(void);
-#define CR3_AVAIL_PCID_BITS (X86_CR3_PCID_BITS - PTI_CONSUMED_PCID_BITS)
+#define TLB_FLUSH_ALL -1UL
-/*
- * ASIDs are zero-based: 0->MAX_AVAIL_ASID are valid. -1 below to account
- * for them being zero-based. Another -1 is because PCID 0 is reserved for
- * use by non-PCID-aware users.
- */
-#define MAX_ASID_AVAILABLE ((1 << CR3_AVAIL_PCID_BITS) - 2)
+void cr4_update_irqsoff(unsigned long set, unsigned long clear);
+unsigned long cr4_read_shadow(void);
-/*
- * 6 because 6 should be plenty and struct tlb_state will fit in two cache
- * lines.
- */
-#define TLB_NR_DYN_ASIDS 6
-
-/*
- * Given @asid, compute kPCID
- */
-static inline u16 kern_pcid(u16 asid)
+/* Set in this cpu's CR4. */
+static inline void cr4_set_bits_irqsoff(unsigned long mask)
{
- VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE);
-
-#ifdef CONFIG_PAGE_TABLE_ISOLATION
- /*
- * Make sure that the dynamic ASID space does not confict with the
- * bit we are using to switch between user and kernel ASIDs.
- */
- BUILD_BUG_ON(TLB_NR_DYN_ASIDS >= (1 << X86_CR3_PTI_PCID_USER_BIT));
-
- /*
- * The ASID being passed in here should have respected the
- * MAX_ASID_AVAILABLE and thus never have the switch bit set.
- */
- VM_WARN_ON_ONCE(asid & (1 << X86_CR3_PTI_PCID_USER_BIT));
-#endif
- /*
- * The dynamically-assigned ASIDs that get passed in are small
- * (<TLB_NR_DYN_ASIDS). They never have the high switch bit set,
- * so do not bother to clear it.
- *
- * If PCID is on, ASID-aware code paths put the ASID+1 into the
- * PCID bits. This serves two purposes. It prevents a nasty
- * situation in which PCID-unaware code saves CR3, loads some other
- * value (with PCID == 0), and then restores CR3, thus corrupting
- * the TLB for ASID 0 if the saved ASID was nonzero. It also means
- * that any bugs involving loading a PCID-enabled CR3 with
- * CR4.PCIDE off will trigger deterministically.
- */
- return asid + 1;
+ cr4_update_irqsoff(mask, 0);
}
-/*
- * Given @asid, compute uPCID
- */
-static inline u16 user_pcid(u16 asid)
+/* Clear in this cpu's CR4. */
+static inline void cr4_clear_bits_irqsoff(unsigned long mask)
{
- u16 ret = kern_pcid(asid);
-#ifdef CONFIG_PAGE_TABLE_ISOLATION
- ret |= 1 << X86_CR3_PTI_PCID_USER_BIT;
-#endif
- return ret;
+ cr4_update_irqsoff(0, mask);
}
-struct pgd_t;
-static inline unsigned long build_cr3(pgd_t *pgd, u16 asid)
+/* Set in this cpu's CR4. */
+static inline void cr4_set_bits(unsigned long mask)
{
- if (static_cpu_has(X86_FEATURE_PCID)) {
- return __sme_pa(pgd) | kern_pcid(asid);
- } else {
- VM_WARN_ON_ONCE(asid != 0);
- return __sme_pa(pgd);
- }
+ unsigned long flags;
+
+ local_irq_save(flags);
+ cr4_set_bits_irqsoff(mask);
+ local_irq_restore(flags);
}
-static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid)
+/* Clear in this cpu's CR4. */
+static inline void cr4_clear_bits(unsigned long mask)
{
- VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE);
- /*
- * Use boot_cpu_has() instead of this_cpu_has() as this function
- * might be called during early boot. This should work even after
- * boot because all CPU's the have same capabilities:
- */
- VM_WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_PCID));
- return __sme_pa(pgd) | kern_pcid(asid) | CR3_NOFLUSH;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ cr4_clear_bits_irqsoff(mask);
+ local_irq_restore(flags);
}
-#ifdef CONFIG_PARAVIRT
-#include <asm/paravirt.h>
-#else
-#define __flush_tlb() __native_flush_tlb()
-#define __flush_tlb_global() __native_flush_tlb_global()
-#define __flush_tlb_one_user(addr) __native_flush_tlb_one_user(addr)
-#endif
+#ifndef MODULE
+/*
+ * 6 because 6 should be plenty and struct tlb_state will fit in two cache
+ * lines.
+ */
+#define TLB_NR_DYN_ASIDS 6
struct tlb_context {
u64 ctx_id;
@@ -242,38 +153,7 @@ struct tlb_state {
};
DECLARE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate);
-/*
- * Blindly accessing user memory from NMI context can be dangerous
- * if we're in the middle of switching the current user task or
- * switching the loaded mm. It can also be dangerous if we
- * interrupted some kernel code that was temporarily using a
- * different mm.
- */
-static inline bool nmi_uaccess_okay(void)
-{
- struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm);
- struct mm_struct *current_mm = current->mm;
-
- VM_WARN_ON_ONCE(!loaded_mm);
-
- /*
- * The condition we want to check is
- * current_mm->pgd == __va(read_cr3_pa()). This may be slow, though,
- * if we're running in a VM with shadow paging, and nmi_uaccess_okay()
- * is supposed to be reasonably fast.
- *
- * Instead, we check the almost equivalent but somewhat conservative
- * condition below, and we rely on the fact that switch_mm_irqs_off()
- * sets loaded_mm to LOADED_MM_SWITCHING before writing to CR3.
- */
- if (loaded_mm != current_mm)
- return false;
-
- VM_WARN_ON_ONCE(current_mm->pgd != __va(read_cr3_pa()));
-
- return true;
-}
-
+bool nmi_uaccess_okay(void);
#define nmi_uaccess_okay nmi_uaccess_okay
/* Initialize cr4 shadow for this CPU. */
@@ -282,250 +162,12 @@ static inline void cr4_init_shadow(void)
this_cpu_write(cpu_tlbstate.cr4, __read_cr4());
}
-static inline void __cr4_set(unsigned long cr4)
-{
- lockdep_assert_irqs_disabled();
- this_cpu_write(cpu_tlbstate.cr4, cr4);
- __write_cr4(cr4);
-}
-
-/* Set in this cpu's CR4. */
-static inline void cr4_set_bits_irqsoff(unsigned long mask)
-{
- unsigned long cr4;
-
- cr4 = this_cpu_read(cpu_tlbstate.cr4);
- if ((cr4 | mask) != cr4)
- __cr4_set(cr4 | mask);
-}
-
-/* Clear in this cpu's CR4. */
-static inline void cr4_clear_bits_irqsoff(unsigned long mask)
-{
- unsigned long cr4;
-
- cr4 = this_cpu_read(cpu_tlbstate.cr4);
- if ((cr4 & ~mask) != cr4)
- __cr4_set(cr4 & ~mask);
-}
-
-/* Set in this cpu's CR4. */
-static inline void cr4_set_bits(unsigned long mask)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- cr4_set_bits_irqsoff(mask);
- local_irq_restore(flags);
-}
-
-/* Clear in this cpu's CR4. */
-static inline void cr4_clear_bits(unsigned long mask)
-{
- unsigned long flags;
-
- local_irq_save(flags);
- cr4_clear_bits_irqsoff(mask);
- local_irq_restore(flags);
-}
-
-static inline void cr4_toggle_bits_irqsoff(unsigned long mask)
-{
- unsigned long cr4;
-
- cr4 = this_cpu_read(cpu_tlbstate.cr4);
- __cr4_set(cr4 ^ mask);
-}
-
-/* Read the CR4 shadow. */
-static inline unsigned long cr4_read_shadow(void)
-{
- return this_cpu_read(cpu_tlbstate.cr4);
-}
-
-/*
- * Mark all other ASIDs as invalid, preserves the current.
- */
-static inline void invalidate_other_asid(void)
-{
- this_cpu_write(cpu_tlbstate.invalidate_other, true);
-}
-
-/*
- * Save some of cr4 feature set we're using (e.g. Pentium 4MB
- * enable and PPro Global page enable), so that any CPU's that boot
- * up after us can get the correct flags. This should only be used
- * during boot on the boot cpu.
- */
extern unsigned long mmu_cr4_features;
extern u32 *trampoline_cr4_features;
-static inline void cr4_set_bits_and_update_boot(unsigned long mask)
-{
- mmu_cr4_features |= mask;
- if (trampoline_cr4_features)
- *trampoline_cr4_features = mmu_cr4_features;
- cr4_set_bits(mask);
-}
-
extern void initialize_tlbstate_and_flush(void);
/*
- * Given an ASID, flush the corresponding user ASID. We can delay this
- * until the next time we switch to it.
- *
- * See SWITCH_TO_USER_CR3.
- */
-static inline void invalidate_user_asid(u16 asid)
-{
- /* There is no user ASID if address space separation is off */
- if (!IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION))
- return;
-
- /*
- * We only have a single ASID if PCID is off and the CR3
- * write will have flushed it.
- */
- if (!cpu_feature_enabled(X86_FEATURE_PCID))
- return;
-
- if (!static_cpu_has(X86_FEATURE_PTI))
- return;
-
- __set_bit(kern_pcid(asid),
- (unsigned long *)this_cpu_ptr(&cpu_tlbstate.user_pcid_flush_mask));
-}
-
-/*
- * flush the entire current user mapping
- */
-static inline void __native_flush_tlb(void)
-{
- /*
- * Preemption or interrupts must be disabled to protect the access
- * to the per CPU variable and to prevent being preempted between
- * read_cr3() and write_cr3().
- */
- WARN_ON_ONCE(preemptible());
-
- invalidate_user_asid(this_cpu_read(cpu_tlbstate.loaded_mm_asid));
-
- /* If current->mm == NULL then the read_cr3() "borrows" an mm */
- native_write_cr3(__native_read_cr3());
-}
-
-/*
- * flush everything
- */
-static inline void __native_flush_tlb_global(void)
-{
- unsigned long cr4, flags;
-
- if (static_cpu_has(X86_FEATURE_INVPCID)) {
- /*
- * Using INVPCID is considerably faster than a pair of writes
- * to CR4 sandwiched inside an IRQ flag save/restore.
- *
- * Note, this works with CR4.PCIDE=0 or 1.
- */
- invpcid_flush_all();
- return;
- }
-
- /*
- * Read-modify-write to CR4 - protect it from preemption and
- * from interrupts. (Use the raw variant because this code can
- * be called from deep inside debugging code.)
- */
- raw_local_irq_save(flags);
-
- cr4 = this_cpu_read(cpu_tlbstate.cr4);
- /* toggle PGE */
- native_write_cr4(cr4 ^ X86_CR4_PGE);
- /* write old PGE again and flush TLBs */
- native_write_cr4(cr4);
-
- raw_local_irq_restore(flags);
-}
-
-/*
- * flush one page in the user mapping
- */
-static inline void __native_flush_tlb_one_user(unsigned long addr)
-{
- u32 loaded_mm_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
-
- asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
-
- if (!static_cpu_has(X86_FEATURE_PTI))
- return;
-
- /*
- * Some platforms #GP if we call invpcid(type=1/2) before CR4.PCIDE=1.
- * Just use invalidate_user_asid() in case we are called early.
- */
- if (!this_cpu_has(X86_FEATURE_INVPCID_SINGLE))
- invalidate_user_asid(loaded_mm_asid);
- else
- invpcid_flush_one(user_pcid(loaded_mm_asid), addr);
-}
-
-/*
- * flush everything
- */
-static inline void __flush_tlb_all(void)
-{
- /*
- * This is to catch users with enabled preemption and the PGE feature
- * and don't trigger the warning in __native_flush_tlb().
- */
- VM_WARN_ON_ONCE(preemptible());
-
- if (boot_cpu_has(X86_FEATURE_PGE)) {
- __flush_tlb_global();
- } else {
- /*
- * !PGE -> !PCID (setup_pcid()), thus every flush is total.
- */
- __flush_tlb();
- }
-}
-
-/*
- * flush one page in the kernel mapping
- */
-static inline void __flush_tlb_one_kernel(unsigned long addr)
-{
- count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
-
- /*
- * If PTI is off, then __flush_tlb_one_user() is just INVLPG or its
- * paravirt equivalent. Even with PCID, this is sufficient: we only
- * use PCID if we also use global PTEs for the kernel mapping, and
- * INVLPG flushes global translations across all address spaces.
- *
- * If PTI is on, then the kernel is mapped with non-global PTEs, and
- * __flush_tlb_one_user() will flush the given address for the current
- * kernel address space and for its usermode counterpart, but it does
- * not flush it for other address spaces.
- */
- __flush_tlb_one_user(addr);
-
- if (!static_cpu_has(X86_FEATURE_PTI))
- return;
-
- /*
- * See above. We need to propagate the flush to all other address
- * spaces. In principle, we only need to propagate it to kernelmode
- * address spaces, but the extra bookkeeping we would need is not
- * worth it.
- */
- invalidate_other_asid();
-}
-
-#define TLB_FLUSH_ALL -1UL
-
-/*
* TLB flushing:
*
* - flush_tlb_all() flushes all processes TLBs
@@ -563,7 +205,15 @@ struct flush_tlb_info {
bool freed_tables;
};
-#define local_flush_tlb() __flush_tlb()
+void flush_tlb_local(void);
+void flush_tlb_one_user(unsigned long addr);
+void flush_tlb_one_kernel(unsigned long addr);
+void flush_tlb_others(const struct cpumask *cpumask,
+ const struct flush_tlb_info *info);
+
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#endif
#define flush_tlb_mm(mm) \
flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL, true)
@@ -585,9 +235,6 @@ static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a)
flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, PAGE_SHIFT, false);
}
-void native_flush_tlb_others(const struct cpumask *cpumask,
- const struct flush_tlb_info *info);
-
static inline u64 inc_mm_tlb_gen(struct mm_struct *mm)
{
/*
@@ -608,12 +255,6 @@ static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch,
extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);
-#ifndef CONFIG_PARAVIRT
-#define flush_tlb_others(mask, info) \
- native_flush_tlb_others(mask, info)
-
-#define paravirt_tlb_remove_table(tlb, page) \
- tlb_remove_page(tlb, (void *)(page))
-#endif
+#endif /* !MODULE */
#endif /* _ASM_X86_TLBFLUSH_H */
diff --git a/arch/x86/include/asm/uv/uv.h b/arch/x86/include/asm/uv/uv.h
index ae587ce544f4..3db85626048f 100644
--- a/arch/x86/include/asm/uv/uv.h
+++ b/arch/x86/include/asm/uv/uv.h
@@ -8,6 +8,7 @@ enum uv_system_type {UV_NONE, UV_LEGACY_APIC, UV_X2APIC, UV_NON_UNIQUE_APIC};
struct cpumask;
struct mm_struct;
+struct flush_tlb_info;
#ifdef CONFIG_X86_UV
#include <linux/efi.h>
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 7867dfb3963e..cd617979b7fc 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -783,6 +783,61 @@ void __init_or_module text_poke_early(void *addr, const void *opcode,
}
}
+typedef struct {
+ struct mm_struct *mm;
+} temp_mm_state_t;
+
+/*
+ * Using a temporary mm allows to set temporary mappings that are not accessible
+ * by other CPUs. Such mappings are needed to perform sensitive memory writes
+ * that override the kernel memory protections (e.g., W^X), without exposing the
+ * temporary page-table mappings that are required for these write operations to
+ * other CPUs. Using a temporary mm also allows to avoid TLB shootdowns when the
+ * mapping is torn down.
+ *
+ * Context: The temporary mm needs to be used exclusively by a single core. To
+ * harden security IRQs must be disabled while the temporary mm is
+ * loaded, thereby preventing interrupt handler bugs from overriding
+ * the kernel memory protection.
+ */
+static inline temp_mm_state_t use_temporary_mm(struct mm_struct *mm)
+{
+ temp_mm_state_t temp_state;
+
+ lockdep_assert_irqs_disabled();
+ temp_state.mm = this_cpu_read(cpu_tlbstate.loaded_mm);
+ switch_mm_irqs_off(NULL, mm, current);
+
+ /*
+ * If breakpoints are enabled, disable them while the temporary mm is
+ * used. Userspace might set up watchpoints on addresses that are used
+ * in the temporary mm, which would lead to wrong signals being sent or
+ * crashes.
+ *
+ * Note that breakpoints are not disabled selectively, which also causes
+ * kernel breakpoints (e.g., perf's) to be disabled. This might be
+ * undesirable, but still seems reasonable as the code that runs in the
+ * temporary mm should be short.
+ */
+ if (hw_breakpoint_active())
+ hw_breakpoint_disable();
+
+ return temp_state;
+}
+
+static inline void unuse_temporary_mm(temp_mm_state_t prev_state)
+{
+ lockdep_assert_irqs_disabled();
+ switch_mm_irqs_off(NULL, prev_state.mm, current);
+
+ /*
+ * Restore the breakpoints if they were disabled before the temporary mm
+ * was loaded.
+ */
+ if (hw_breakpoint_active())
+ hw_breakpoint_restore();
+}
+
__ro_after_init struct mm_struct *poking_mm;
__ro_after_init unsigned long poking_addr;
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index d07809286b95..74682b8d09b0 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -387,7 +387,30 @@ set_register:
bits_missing);
}
}
-EXPORT_SYMBOL(native_write_cr4);
+#if IS_MODULE(CONFIG_LKDTM)
+EXPORT_SYMBOL_GPL(native_write_cr4);
+#endif
+
+void cr4_update_irqsoff(unsigned long set, unsigned long clear)
+{
+ unsigned long newval, cr4 = this_cpu_read(cpu_tlbstate.cr4);
+
+ lockdep_assert_irqs_disabled();
+
+ newval = (cr4 & ~clear) | set;
+ if (newval != cr4) {
+ this_cpu_write(cpu_tlbstate.cr4, newval);
+ __write_cr4(newval);
+ }
+}
+EXPORT_SYMBOL(cr4_update_irqsoff);
+
+/* Read the CR4 shadow. */
+unsigned long cr4_read_shadow(void)
+{
+ return this_cpu_read(cpu_tlbstate.cr4);
+}
+EXPORT_SYMBOL_GPL(cr4_read_shadow);
void cr4_init(void)
{
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index 51b9190c628b..23ad8e953dfb 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -761,7 +761,7 @@ static void prepare_set(void) __acquires(set_atomicity_lock)
/* Flush all TLBs via a mov %cr3, %reg; mov %reg, %cr3 */
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
- __flush_tlb();
+ flush_tlb_local();
/* Save MTRR state */
rdmsr(MSR_MTRRdefType, deftype_lo, deftype_hi);
@@ -778,7 +778,7 @@ static void post_set(void) __releases(set_atomicity_lock)
{
/* Flush TLBs (no need to flush caches - they are disabled) */
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
- __flush_tlb();
+ flush_tlb_local();
/* Intel (P6) standard MTRRs */
mtrr_wrmsr(MSR_MTRRdefType, deftype_lo, deftype_hi);
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index c131ba4e70ef..5638e4ae2ea6 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -160,25 +160,6 @@ unsigned paravirt_patch_insns(void *insn_buff, unsigned len,
return insn_len;
}
-static void native_flush_tlb(void)
-{
- __native_flush_tlb();
-}
-
-/*
- * Global pages have to be flushed a bit differently. Not a real
- * performance problem because this does not happen often.
- */
-static void native_flush_tlb_global(void)
-{
- __native_flush_tlb_global();
-}
-
-static void native_flush_tlb_one_user(unsigned long addr)
-{
- __native_flush_tlb_one_user(addr);
-}
-
struct static_key paravirt_steal_enabled;
struct static_key paravirt_steal_rq_enabled;
@@ -359,7 +340,7 @@ struct paravirt_patch_template pv_ops = {
#endif /* CONFIG_PARAVIRT_XXL */
/* Mmu ops. */
- .mmu.flush_tlb_user = native_flush_tlb,
+ .mmu.flush_tlb_user = native_flush_tlb_local,
.mmu.flush_tlb_kernel = native_flush_tlb_global,
.mmu.flush_tlb_one_user = native_flush_tlb_one_user,
.mmu.flush_tlb_others = native_flush_tlb_others,
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index ce6cd220f722..8e3d0347b664 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -612,6 +612,17 @@ void speculation_ctrl_update_current(void)
preempt_enable();
}
+static inline void cr4_toggle_bits_irqsoff(unsigned long mask)
+{
+ unsigned long newval, cr4 = this_cpu_read(cpu_tlbstate.cr4);
+
+ newval = cr4 ^ mask;
+ if (newval != cr4) {
+ this_cpu_write(cpu_tlbstate.cr4, newval);
+ __write_cr4(newval);
+ }
+}
+
void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p)
{
unsigned long tifp, tifn;
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 1decb645dac0..112d3b98a3b6 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -49,7 +49,7 @@
* Index into __pte2cachemode_tbl[] are the caching attribute bits of the pte
* (_PAGE_PWT, _PAGE_PCD, _PAGE_PAT) at index bit positions 0, 1, 2.
*/
-uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = {
+static uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = {
[_PAGE_CACHE_MODE_WB ] = 0 | 0 ,
[_PAGE_CACHE_MODE_WC ] = 0 | _PAGE_PCD,
[_PAGE_CACHE_MODE_UC_MINUS] = 0 | _PAGE_PCD,
@@ -57,9 +57,16 @@ uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = {
[_PAGE_CACHE_MODE_WT ] = 0 | _PAGE_PCD,
[_PAGE_CACHE_MODE_WP ] = 0 | _PAGE_PCD,
};
-EXPORT_SYMBOL(__cachemode2pte_tbl);
-uint8_t __pte2cachemode_tbl[8] = {
+unsigned long cachemode2protval(enum page_cache_mode pcm)
+{
+ if (likely(pcm == 0))
+ return 0;
+ return __cachemode2pte_tbl[pcm];
+}
+EXPORT_SYMBOL(cachemode2protval);
+
+static uint8_t __pte2cachemode_tbl[8] = {
[__pte2cm_idx( 0 | 0 | 0 )] = _PAGE_CACHE_MODE_WB,
[__pte2cm_idx(_PAGE_PWT | 0 | 0 )] = _PAGE_CACHE_MODE_UC_MINUS,
[__pte2cm_idx( 0 | _PAGE_PCD | 0 )] = _PAGE_CACHE_MODE_UC_MINUS,
@@ -69,7 +76,22 @@ uint8_t __pte2cachemode_tbl[8] = {
[__pte2cm_idx(0 | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS,
[__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC,
};
-EXPORT_SYMBOL(__pte2cachemode_tbl);
+
+/* Check that the write-protect PAT entry is set for write-protect */
+bool x86_has_pat_wp(void)
+{
+ return __pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] == _PAGE_CACHE_MODE_WP;
+}
+
+enum page_cache_mode pgprot2cachemode(pgprot_t pgprot)
+{
+ unsigned long masked;
+
+ masked = pgprot_val(pgprot) & _PAGE_CACHE_MASK;
+ if (likely(masked == 0))
+ return 0;
+ return __pte2cachemode_tbl[__pte2cm_idx(masked)];
+}
static unsigned long __initdata pgt_buf_start;
static unsigned long __initdata pgt_buf_end;
@@ -170,6 +192,19 @@ struct map_range {
static int page_size_mask;
+/*
+ * Save some of cr4 feature set we're using (e.g. Pentium 4MB
+ * enable and PPro Global page enable), so that any CPU's that boot
+ * up after us can get the correct flags. Invoked on the boot CPU.
+ */
+static inline void cr4_set_bits_and_update_boot(unsigned long mask)
+{
+ mmu_cr4_features |= mask;
+ if (trampoline_cr4_features)
+ *trampoline_cr4_features = mmu_cr4_features;
+ cr4_set_bits(mask);
+}
+
static void __init probe_page_size_mask(void)
{
/*
@@ -955,7 +990,6 @@ __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate) = {
.next_asid = 1,
.cr4 = ~0UL, /* fail hard if we screw up cr4 shadow initialization */
};
-EXPORT_PER_CPU_SYMBOL(cpu_tlbstate);
void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache)
{
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index e08f1007f776..add03c35aa34 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -304,7 +304,7 @@ static void __set_pte_vaddr(pud_t *pud, unsigned long vaddr, pte_t new_pte)
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
- __flush_tlb_one_kernel(vaddr);
+ flush_tlb_one_kernel(vaddr);
}
void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte)
@@ -373,7 +373,7 @@ static void __init __init_extra_mapping(unsigned long phys, unsigned long size,
pgprot_t prot;
pgprot_val(prot) = pgprot_val(PAGE_KERNEL_LARGE) |
- pgprot_val(pgprot_4k_2_large(cachemode2pgprot(cache)));
+ protval_4k_2_large(cachemode2protval(cache));
BUG_ON((phys & ~PMD_MASK) || (size & ~PMD_MASK));
for (; size; phys += PMD_SIZE, size -= PMD_SIZE) {
pgd = pgd_offset_k((unsigned long)__va(phys));
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 18c637c0dc6f..986d57534fd6 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -778,10 +778,8 @@ void __init *early_memremap_encrypted(resource_size_t phys_addr,
void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
unsigned long size)
{
- /* Be sure the write-protect PAT entry is set for write-protect */
- if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP)
+ if (!x86_has_pat_wp())
return NULL;
-
return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC_WP);
}
@@ -799,10 +797,8 @@ void __init *early_memremap_decrypted(resource_size_t phys_addr,
void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
unsigned long size)
{
- /* Be sure the write-protect PAT entry is set for write-protect */
- if (__pte2cachemode_tbl[_PAGE_CACHE_MODE_WP] != _PAGE_CACHE_MODE_WP)
+ if (!x86_has_pat_wp())
return NULL;
-
return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC_WP);
}
#endif /* CONFIG_AMD_MEM_ENCRYPT */
@@ -889,5 +885,5 @@ void __init __early_set_fixmap(enum fixed_addresses idx,
set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
else
pte_clear(&init_mm, addr, pte);
- __flush_tlb_one_kernel(addr);
+ flush_tlb_one_kernel(addr);
}
diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c
index 22bae5828c3d..be020a7bc414 100644
--- a/arch/x86/mm/kmmio.c
+++ b/arch/x86/mm/kmmio.c
@@ -173,7 +173,7 @@ static int clear_page_presence(struct kmmio_fault_page *f, bool clear)
return -1;
}
- __flush_tlb_one_kernel(f->addr);
+ flush_tlb_one_kernel(f->addr);
return 0;
}
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index a03614bd3e1a..4a781cf99e92 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -134,7 +134,7 @@ static void __init __sme_early_map_unmap_mem(void *vaddr, unsigned long size,
size = (size <= PMD_SIZE) ? 0 : size - PMD_SIZE;
} while (size);
- __native_flush_tlb();
+ flush_tlb_local();
}
void __init sme_unmap_bootdata(char *real_mode_data)
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index b8c55a2e402d..77e04304a2a7 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -69,6 +69,11 @@ static DEFINE_SPINLOCK(cpa_lock);
#define CPA_PAGES_ARRAY 4
#define CPA_NO_CHECK_ALIAS 8 /* Do not search for aliases */
+static inline pgprot_t cachemode2pgprot(enum page_cache_mode pcm)
+{
+ return __pgprot(cachemode2protval(pcm));
+}
+
#ifdef CONFIG_PROC_FS
static unsigned long direct_pages_count[PG_LEVEL_NUM];
@@ -341,7 +346,7 @@ static void __cpa_flush_tlb(void *data)
unsigned int i;
for (i = 0; i < cpa->numpages; i++)
- __flush_tlb_one_kernel(fix_addr(__cpa_addr(cpa, i)));
+ flush_tlb_one_kernel(fix_addr(__cpa_addr(cpa, i)));
}
static void cpa_flush(struct cpa_data *data, int cache)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 7bd2c3a52297..d88e9064c28e 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -19,6 +19,14 @@ EXPORT_SYMBOL(physical_mask);
#define PGTABLE_HIGHMEM 0
#endif
+#ifndef CONFIG_PARAVIRT
+static inline
+void paravirt_tlb_remove_table(struct mmu_gather *tlb, void *table)
+{
+ tlb_remove_page(tlb, table);
+}
+#endif
+
gfp_t __userpte_alloc_gfp = GFP_PGTABLE_USER | PGTABLE_HIGHMEM;
pgtable_t pte_alloc_one(struct mm_struct *mm)
@@ -706,11 +714,9 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
if (pud_present(*pud) && !pud_huge(*pud))
return 0;
- prot = pgprot_4k_2_large(prot);
-
set_pte((pte_t *)pud, pfn_pte(
(u64)addr >> PAGE_SHIFT,
- __pgprot(pgprot_val(prot) | _PAGE_PSE)));
+ __pgprot(protval_4k_2_large(pgprot_val(prot)) | _PAGE_PSE)));
return 1;
}
@@ -738,11 +744,9 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
if (pmd_present(*pmd) && !pmd_huge(*pmd))
return 0;
- prot = pgprot_4k_2_large(prot);
-
set_pte((pte_t *)pmd, pfn_pte(
(u64)addr >> PAGE_SHIFT,
- __pgprot(pgprot_val(prot) | _PAGE_PSE)));
+ __pgprot(protval_4k_2_large(pgprot_val(prot)) | _PAGE_PSE)));
return 1;
}
diff --git a/arch/x86/mm/pgtable_32.c b/arch/x86/mm/pgtable_32.c
index 0e6700eaa4f9..e1ce59dc558f 100644
--- a/arch/x86/mm/pgtable_32.c
+++ b/arch/x86/mm/pgtable_32.c
@@ -64,7 +64,7 @@ void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
- __flush_tlb_one_kernel(vaddr);
+ flush_tlb_one_kernel(vaddr);
}
unsigned long __FIXADDR_TOP = 0xfffff000;
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index f3fe261e5936..1a3569b43aa5 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -18,6 +18,16 @@
#include "mm_internal.h"
+#ifdef CONFIG_PARAVIRT
+# define STATIC_NOPV
+#else
+# define STATIC_NOPV static
+# define __flush_tlb_local native_flush_tlb_local
+# define __flush_tlb_global native_flush_tlb_global
+# define __flush_tlb_one_user(addr) native_flush_tlb_one_user(addr)
+# define __flush_tlb_others(msk, info) native_flush_tlb_others(msk, info)
+#endif
+
/*
* TLB flushing, formerly SMP-only
* c/o Linus Torvalds.
@@ -39,6 +49,126 @@
#define LAST_USER_MM_IBPB 0x1UL
/*
+ * The x86 feature is called PCID (Process Context IDentifier). It is similar
+ * to what is traditionally called ASID on the RISC processors.
+ *
+ * We don't use the traditional ASID implementation, where each process/mm gets
+ * its own ASID and flush/restart when we run out of ASID space.
+ *
+ * Instead we have a small per-cpu array of ASIDs and cache the last few mm's
+ * that came by on this CPU, allowing cheaper switch_mm between processes on
+ * this CPU.
+ *
+ * We end up with different spaces for different things. To avoid confusion we
+ * use different names for each of them:
+ *
+ * ASID - [0, TLB_NR_DYN_ASIDS-1]
+ * the canonical identifier for an mm
+ *
+ * kPCID - [1, TLB_NR_DYN_ASIDS]
+ * the value we write into the PCID part of CR3; corresponds to the
+ * ASID+1, because PCID 0 is special.
+ *
+ * uPCID - [2048 + 1, 2048 + TLB_NR_DYN_ASIDS]
+ * for KPTI each mm has two address spaces and thus needs two
+ * PCID values, but we can still do with a single ASID denomination
+ * for each mm. Corresponds to kPCID + 2048.
+ *
+ */
+
+/* There are 12 bits of space for ASIDS in CR3 */
+#define CR3_HW_ASID_BITS 12
+
+/*
+ * When enabled, PAGE_TABLE_ISOLATION consumes a single bit for
+ * user/kernel switches
+ */
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+# define PTI_CONSUMED_PCID_BITS 1
+#else
+# define PTI_CONSUMED_PCID_BITS 0
+#endif
+
+#define CR3_AVAIL_PCID_BITS (X86_CR3_PCID_BITS - PTI_CONSUMED_PCID_BITS)
+
+/*
+ * ASIDs are zero-based: 0->MAX_AVAIL_ASID are valid. -1 below to account
+ * for them being zero-based. Another -1 is because PCID 0 is reserved for
+ * use by non-PCID-aware users.
+ */
+#define MAX_ASID_AVAILABLE ((1 << CR3_AVAIL_PCID_BITS) - 2)
+
+/*
+ * Given @asid, compute kPCID
+ */
+static inline u16 kern_pcid(u16 asid)
+{
+ VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE);
+
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+ /*
+ * Make sure that the dynamic ASID space does not confict with the
+ * bit we are using to switch between user and kernel ASIDs.
+ */
+ BUILD_BUG_ON(TLB_NR_DYN_ASIDS >= (1 << X86_CR3_PTI_PCID_USER_BIT));
+
+ /*
+ * The ASID being passed in here should have respected the
+ * MAX_ASID_AVAILABLE and thus never have the switch bit set.
+ */
+ VM_WARN_ON_ONCE(asid & (1 << X86_CR3_PTI_PCID_USER_BIT));
+#endif
+ /*
+ * The dynamically-assigned ASIDs that get passed in are small
+ * (<TLB_NR_DYN_ASIDS). They never have the high switch bit set,
+ * so do not bother to clear it.
+ *
+ * If PCID is on, ASID-aware code paths put the ASID+1 into the
+ * PCID bits. This serves two purposes. It prevents a nasty
+ * situation in which PCID-unaware code saves CR3, loads some other
+ * value (with PCID == 0), and then restores CR3, thus corrupting
+ * the TLB for ASID 0 if the saved ASID was nonzero. It also means
+ * that any bugs involving loading a PCID-enabled CR3 with
+ * CR4.PCIDE off will trigger deterministically.
+ */
+ return asid + 1;
+}
+
+/*
+ * Given @asid, compute uPCID
+ */
+static inline u16 user_pcid(u16 asid)
+{
+ u16 ret = kern_pcid(asid);
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+ ret |= 1 << X86_CR3_PTI_PCID_USER_BIT;
+#endif
+ return ret;
+}
+
+static inline unsigned long build_cr3(pgd_t *pgd, u16 asid)
+{
+ if (static_cpu_has(X86_FEATURE_PCID)) {
+ return __sme_pa(pgd) | kern_pcid(asid);
+ } else {
+ VM_WARN_ON_ONCE(asid != 0);
+ return __sme_pa(pgd);
+ }
+}
+
+static inline unsigned long build_cr3_noflush(pgd_t *pgd, u16 asid)
+{
+ VM_WARN_ON_ONCE(asid > MAX_ASID_AVAILABLE);
+ /*
+ * Use boot_cpu_has() instead of this_cpu_has() as this function
+ * might be called during early boot. This should work even after
+ * boot because all CPU's the have same capabilities:
+ */
+ VM_WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_PCID));
+ return __sme_pa(pgd) | kern_pcid(asid) | CR3_NOFLUSH;
+}
+
+/*
* We get here when we do something requiring a TLB invalidation
* but could not go invalidate all of the contexts. We do the
* necessary invalidation by clearing out the 'ctx_id' which
@@ -110,6 +240,32 @@ static void choose_new_asid(struct mm_struct *next, u64 next_tlb_gen,
*need_flush = true;
}
+/*
+ * Given an ASID, flush the corresponding user ASID. We can delay this
+ * until the next time we switch to it.
+ *
+ * See SWITCH_TO_USER_CR3.
+ */
+static inline void invalidate_user_asid(u16 asid)
+{
+ /* There is no user ASID if address space separation is off */
+ if (!IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION))
+ return;
+
+ /*
+ * We only have a single ASID if PCID is off and the CR3
+ * write will have flushed it.
+ */
+ if (!cpu_feature_enabled(X86_FEATURE_PCID))
+ return;
+
+ if (!static_cpu_has(X86_FEATURE_PTI))
+ return;
+
+ __set_bit(kern_pcid(asid),
+ (unsigned long *)this_cpu_ptr(&cpu_tlbstate.user_pcid_flush_mask));
+}
+
static void load_new_mm_cr3(pgd_t *pgdir, u16 new_asid, bool need_flush)
{
unsigned long new_mm_cr3;
@@ -244,6 +400,26 @@ static void cond_ibpb(struct task_struct *next)
}
}
+#ifdef CONFIG_PERF_EVENTS
+static inline void cr4_update_pce_mm(struct mm_struct *mm)
+{
+ if (static_branch_unlikely(&rdpmc_always_available_key) ||
+ (!static_branch_unlikely(&rdpmc_never_available_key) &&
+ atomic_read(&mm->context.perf_rdpmc_allowed)))
+ cr4_set_bits_irqsoff(X86_CR4_PCE);
+ else
+ cr4_clear_bits_irqsoff(X86_CR4_PCE);
+}
+
+void cr4_update_pce(void *ignored)
+{
+ cr4_update_pce_mm(this_cpu_read(cpu_tlbstate.loaded_mm));
+}
+
+#else
+static inline void cr4_update_pce_mm(struct mm_struct *mm) { }
+#endif
+
void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
@@ -403,7 +579,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
this_cpu_write(cpu_tlbstate.loaded_mm_asid, new_asid);
if (next != real_prev) {
- load_mm_cr4_irqsoff(next);
+ cr4_update_pce_mm(next);
switch_ldt(real_prev, next);
}
}
@@ -580,7 +756,7 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f,
unsigned long addr = f->start;
while (addr < f->end) {
- __flush_tlb_one_user(addr);
+ flush_tlb_one_user(addr);
addr += 1UL << f->stride_shift;
}
if (local)
@@ -588,7 +764,7 @@ static void flush_tlb_func_common(const struct flush_tlb_info *f,
trace_tlb_flush(reason, nr_invalidate);
} else {
/* Full flush. */
- local_flush_tlb();
+ flush_tlb_local();
if (local)
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
trace_tlb_flush(reason, TLB_FLUSH_ALL);
@@ -623,8 +799,8 @@ static bool tlb_is_not_lazy(int cpu, void *data)
return !per_cpu(cpu_tlbstate.is_lazy, cpu);
}
-void native_flush_tlb_others(const struct cpumask *cpumask,
- const struct flush_tlb_info *info)
+STATIC_NOPV void native_flush_tlb_others(const struct cpumask *cpumask,
+ const struct flush_tlb_info *info)
{
count_vm_tlb_event(NR_TLB_REMOTE_FLUSH);
if (info->end == TLB_FLUSH_ALL)
@@ -674,6 +850,12 @@ void native_flush_tlb_others(const struct cpumask *cpumask,
(void *)info, 1, cpumask);
}
+void flush_tlb_others(const struct cpumask *cpumask,
+ const struct flush_tlb_info *info)
+{
+ __flush_tlb_others(cpumask, info);
+}
+
/*
* See Documentation/x86/tlb.rst for details. We choose 33
* because it is large enough to cover the vast majority (at
@@ -784,7 +966,7 @@ static void do_kernel_range_flush(void *info)
/* flush range by one by one 'invlpg' */
for (addr = f->start; addr < f->end; addr += PAGE_SIZE)
- __flush_tlb_one_kernel(addr);
+ flush_tlb_one_kernel(addr);
}
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
@@ -807,6 +989,164 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end)
}
/*
+ * This can be used from process context to figure out what the value of
+ * CR3 is without needing to do a (slow) __read_cr3().
+ *
+ * It's intended to be used for code like KVM that sneakily changes CR3
+ * and needs to restore it. It needs to be used very carefully.
+ */
+unsigned long __get_current_cr3_fast(void)
+{
+ unsigned long cr3 = build_cr3(this_cpu_read(cpu_tlbstate.loaded_mm)->pgd,
+ this_cpu_read(cpu_tlbstate.loaded_mm_asid));
+
+ /* For now, be very restrictive about when this can be called. */
+ VM_WARN_ON(in_nmi() || preemptible());
+
+ VM_BUG_ON(cr3 != __read_cr3());
+ return cr3;
+}
+EXPORT_SYMBOL_GPL(__get_current_cr3_fast);
+
+/*
+ * Flush one page in the kernel mapping
+ */
+void flush_tlb_one_kernel(unsigned long addr)
+{
+ count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
+
+ /*
+ * If PTI is off, then __flush_tlb_one_user() is just INVLPG or its
+ * paravirt equivalent. Even with PCID, this is sufficient: we only
+ * use PCID if we also use global PTEs for the kernel mapping, and
+ * INVLPG flushes global translations across all address spaces.
+ *
+ * If PTI is on, then the kernel is mapped with non-global PTEs, and
+ * __flush_tlb_one_user() will flush the given address for the current
+ * kernel address space and for its usermode counterpart, but it does
+ * not flush it for other address spaces.
+ */
+ flush_tlb_one_user(addr);
+
+ if (!static_cpu_has(X86_FEATURE_PTI))
+ return;
+
+ /*
+ * See above. We need to propagate the flush to all other address
+ * spaces. In principle, we only need to propagate it to kernelmode
+ * address spaces, but the extra bookkeeping we would need is not
+ * worth it.
+ */
+ this_cpu_write(cpu_tlbstate.invalidate_other, true);
+}
+
+/*
+ * Flush one page in the user mapping
+ */
+STATIC_NOPV void native_flush_tlb_one_user(unsigned long addr)
+{
+ u32 loaded_mm_asid = this_cpu_read(cpu_tlbstate.loaded_mm_asid);
+
+ asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
+
+ if (!static_cpu_has(X86_FEATURE_PTI))
+ return;
+
+ /*
+ * Some platforms #GP if we call invpcid(type=1/2) before CR4.PCIDE=1.
+ * Just use invalidate_user_asid() in case we are called early.
+ */
+ if (!this_cpu_has(X86_FEATURE_INVPCID_SINGLE))
+ invalidate_user_asid(loaded_mm_asid);
+ else
+ invpcid_flush_one(user_pcid(loaded_mm_asid), addr);
+}
+
+void flush_tlb_one_user(unsigned long addr)
+{
+ __flush_tlb_one_user(addr);
+}
+
+/*
+ * Flush everything
+ */
+STATIC_NOPV void native_flush_tlb_global(void)
+{
+ unsigned long cr4, flags;
+
+ if (static_cpu_has(X86_FEATURE_INVPCID)) {
+ /*
+ * Using INVPCID is considerably faster than a pair of writes
+ * to CR4 sandwiched inside an IRQ flag save/restore.
+ *
+ * Note, this works with CR4.PCIDE=0 or 1.
+ */
+ invpcid_flush_all();
+ return;
+ }
+
+ /*
+ * Read-modify-write to CR4 - protect it from preemption and
+ * from interrupts. (Use the raw variant because this code can
+ * be called from deep inside debugging code.)
+ */
+ raw_local_irq_save(flags);
+
+ cr4 = this_cpu_read(cpu_tlbstate.cr4);
+ /* toggle PGE */
+ native_write_cr4(cr4 ^ X86_CR4_PGE);
+ /* write old PGE again and flush TLBs */
+ native_write_cr4(cr4);
+
+ raw_local_irq_restore(flags);
+}
+
+/*
+ * Flush the entire current user mapping
+ */
+STATIC_NOPV void native_flush_tlb_local(void)
+{
+ /*
+ * Preemption or interrupts must be disabled to protect the access
+ * to the per CPU variable and to prevent being preempted between
+ * read_cr3() and write_cr3().
+ */
+ WARN_ON_ONCE(preemptible());
+
+ invalidate_user_asid(this_cpu_read(cpu_tlbstate.loaded_mm_asid));
+
+ /* If current->mm == NULL then the read_cr3() "borrows" an mm */
+ native_write_cr3(__native_read_cr3());
+}
+
+void flush_tlb_local(void)
+{
+ __flush_tlb_local();
+}
+
+/*
+ * Flush everything
+ */
+void __flush_tlb_all(void)
+{
+ /*
+ * This is to catch users with enabled preemption and the PGE feature
+ * and don't trigger the warning in __native_flush_tlb().
+ */
+ VM_WARN_ON_ONCE(preemptible());
+
+ if (boot_cpu_has(X86_FEATURE_PGE)) {
+ __flush_tlb_global();
+ } else {
+ /*
+ * !PGE -> !PCID (setup_pcid()), thus every flush is total.
+ */
+ flush_tlb_local();
+ }
+}
+EXPORT_SYMBOL_GPL(__flush_tlb_all);
+
+/*
* arch_tlbbatch_flush() performs a full TLB flush regardless of the active mm.
* This means that the 'struct flush_tlb_info' that describes which mappings to
* flush is actually fixed. We therefore set a single fixed struct and use it in
@@ -837,6 +1177,38 @@ void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
put_cpu();
}
+/*
+ * Blindly accessing user memory from NMI context can be dangerous
+ * if we're in the middle of switching the current user task or
+ * switching the loaded mm. It can also be dangerous if we
+ * interrupted some kernel code that was temporarily using a
+ * different mm.
+ */
+bool nmi_uaccess_okay(void)
+{
+ struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm);
+ struct mm_struct *current_mm = current->mm;
+
+ VM_WARN_ON_ONCE(!loaded_mm);
+
+ /*
+ * The condition we want to check is
+ * current_mm->pgd == __va(read_cr3_pa()). This may be slow, though,
+ * if we're running in a VM with shadow paging, and nmi_uaccess_okay()
+ * is supposed to be reasonably fast.
+ *
+ * Instead, we check the almost equivalent but somewhat conservative
+ * condition below, and we rely on the fact that switch_mm_irqs_off()
+ * sets loaded_mm to LOADED_MM_SWITCHING before writing to CR3.
+ */
+ if (loaded_mm != current_mm)
+ return false;
+
+ VM_WARN_ON_ONCE(current_mm->pgd != __va(read_cr3_pa()));
+
+ return true;
+}
+
static ssize_t tlbflush_read_file(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
index 1fd321f37f1b..4ea69690c3e4 100644
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -293,10 +293,10 @@ static void bau_process_message(struct msg_desc *mdp, struct bau_control *bcp,
* This must be a normal message, or retry of a normal message
*/
if (msg->address == TLB_FLUSH_ALL) {
- local_flush_tlb();
+ flush_tlb_local();
stat->d_alltlb++;
} else {
- __flush_tlb_one_user(msg->address);
+ flush_tlb_one_user(msg->address);
stat->d_onetlb++;
}
stat->d_requestee++;
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index c6070e70dd73..b8ccb8990bfd 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -27,7 +27,6 @@
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
-#include <asm/tlb.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>