The patch titled
Subject: mm: add PTE pointer parameter to flush_tlb_fix_spurious_fault()
has been added to the -mm mm-unstable branch. Its filename is
mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Subject: mm: add PTE pointer parameter to flush_tlb_fix_spurious_fault()
Date: Mon, 6 Mar 2023 17:15:48 +0100
s390 can do more fine-grained handling of spurious TLB protection faults,
when there also is the PTE pointer available.
Therefore, pass on the PTE pointer to flush_tlb_fix_spurious_fault() as an
additional parameter.
This will add no functional change to other architectures, but those with
private flush_tlb_fix_spurious_fault() implementations need to be made
aware of the new parameter.
Link: https://lkml.kernel.org/r/20230306161548.661740-1-gerald.schaefer@xxxxxxxxxxxxx
Signed-off-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Reviewed-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx> [arm64]
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/arch/arm64/include/asm/pgtable.h~mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault
+++ a/arch/arm64/include/asm/pgtable.h
@@ -57,7 +57,7 @@ static inline bool arch_thp_swp_supporte
* fault on one CPU which has been handled concurrently by another CPU
* does not need to perform additional invalidation.
*/
-#define flush_tlb_fix_spurious_fault(vma, address) do { } while (0)
+#define flush_tlb_fix_spurious_fault(vma, address, ptep) do { } while (0)
/*
* ZERO_PAGE is a global shared page that is always zero: used
--- a/arch/mips/include/asm/pgtable.h~mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault
+++ a/arch/mips/include/asm/pgtable.h
@@ -469,7 +469,8 @@ static inline pgprot_t pgprot_writecombi
}
static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma,
- unsigned long address)
+ unsigned long address,
+ pte_t *ptep)
{
}
--- a/arch/powerpc/include/asm/book3s/64/tlbflush.h~mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault
+++ a/arch/powerpc/include/asm/book3s/64/tlbflush.h
@@ -121,7 +121,8 @@ static inline void flush_tlb_page(struct
#define flush_tlb_fix_spurious_fault flush_tlb_fix_spurious_fault
static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma,
- unsigned long address)
+ unsigned long address,
+ pte_t *ptep)
{
/*
* Book3S 64 does not require spurious fault flushes because the PTE
--- a/arch/s390/include/asm/pgtable.h~mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault
+++ a/arch/s390/include/asm/pgtable.h
@@ -1239,7 +1239,8 @@ static inline int pte_allow_rdp(pte_t ol
}
static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma,
- unsigned long address)
+ unsigned long address,
+ pte_t *ptep)
{
/*
* RDP might not have propagated the PTE protection reset to all CPUs,
@@ -1247,11 +1248,12 @@ static inline void flush_tlb_fix_spuriou
* NOTE: This will also be called when a racing pagetable update on
* another thread already installed the correct PTE. Both cases cannot
* really be distinguished.
- * Therefore, only do the local TLB flush when RDP can be used, to avoid
- * unnecessary overhead.
+ * Therefore, only do the local TLB flush when RDP can be used, and the
+ * PTE does not have _PAGE_PROTECT set, to avoid unnecessary overhead.
+ * A local RDP can be used to do the flush.
*/
- if (MACHINE_HAS_RDP)
- asm volatile("ptlb" : : : "memory");
+ if (MACHINE_HAS_RDP && !(pte_val(*ptep) & _PAGE_PROTECT))
+ __ptep_rdp(address, ptep, 0, 0, 1);
}
#define flush_tlb_fix_spurious_fault flush_tlb_fix_spurious_fault
--- a/arch/x86/include/asm/pgtable.h~mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault
+++ a/arch/x86/include/asm/pgtable.h
@@ -1097,7 +1097,7 @@ static inline void ptep_set_wrprotect(st
clear_bit(_PAGE_BIT_RW, (unsigned long *)&ptep->pte);
}
-#define flush_tlb_fix_spurious_fault(vma, address) do { } while (0)
+#define flush_tlb_fix_spurious_fault(vma, address, ptep) do { } while (0)
#define mk_pmd(page, pgprot) pfn_pmd(page_to_pfn(page), (pgprot))
--- a/include/linux/pgtable.h~mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault
+++ a/include/linux/pgtable.h
@@ -817,7 +817,7 @@ static inline void arch_swap_restore(swp
#endif
#ifndef flush_tlb_fix_spurious_fault
-#define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
+#define flush_tlb_fix_spurious_fault(vma, address, ptep) flush_tlb_page(vma, address)
#endif
/*
--- a/mm/memory.c~mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault
+++ a/mm/memory.c
@@ -4956,7 +4956,8 @@ static vm_fault_t handle_pte_fault(struc
* with threads.
*/
if (vmf->flags & FAULT_FLAG_WRITE)
- flush_tlb_fix_spurious_fault(vmf->vma, vmf->address);
+ flush_tlb_fix_spurious_fault(vmf->vma, vmf->address,
+ vmf->pte);
}
unlock:
pte_unmap_unlock(vmf->pte, vmf->ptl);
--- a/mm/pgtable-generic.c~mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault
+++ a/mm/pgtable-generic.c
@@ -69,7 +69,7 @@ int ptep_set_access_flags(struct vm_area
int changed = !pte_same(*ptep, entry);
if (changed) {
set_pte_at(vma->vm_mm, address, ptep, entry);
- flush_tlb_fix_spurious_fault(vma, address);
+ flush_tlb_fix_spurious_fault(vma, address, ptep);
}
return changed;
}
_
Patches currently in -mm which might be from gerald.schaefer@xxxxxxxxxxxxx are
mm-add-pte-pointer-parameter-to-flush_tlb_fix_spurious_fault.patch
