From: Rohan McLure Date: Thu, 18 Dec 2025 17:09:44 +0000 (+1100) Subject: powerpc/mm: support page table check X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=641d47d4c9635987f2329054b1395421716d3fee;p=thirdparty%2Fkernel%2Flinux.git powerpc/mm: support page table check On creation and clearing of a page table mapping, instrument such calls by invoking page_table_check_pte_set and page_table_check_pte_clear respectively. These calls serve as a sanity check against illegal mappings. Enable ARCH_SUPPORTS_PAGE_TABLE_CHECK on powerpc, except when HUGETLB_PAGE is enabled (powerpc has some weirdness in how it implements set_huge_pte_at(), which may require some further work). See also: riscv support in commit 3fee229a8eb9 ("riscv/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") arm64 in commit 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") x86_64 in commit d283d422c6c4 ("x86: mm: add x86_64 support for page table check") [ajd@linux.ibm.com: rebase, add additional instrumentation, misc fixes] Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-12-755bc151a50b@linux.ibm.com Signed-off-by: Rohan McLure Signed-off-by: Andrew Donnellan Reviewed-by: Christophe Leroy Reviewed-by: Pasha Tatashin Acked-by: Madhavan Srinivasan Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Alexandre Ghiti Cc: Alistair Popple Cc: "Christophe Leroy (CS GROUP)" Cc: David Hildenbrand Cc: Donet Tom Cc: Guo Weikang Cc: Ingo Molnar Cc: Jason Gunthorpe Cc: Kevin Brodsky Cc: Magnus Lindholm Cc: "Matthew Wilcox (Oracle)" Cc: Michael Ellerman Cc: Nicholas Miehlbradt Cc: Nicholas Piggin Cc: Paul Mackerras Cc: Qi Zheng Cc: "Ritesh Harjani (IBM)" Cc: Sweet Tea Dorminy Cc: Thomas Huth Cc: "Vishal Moola (Oracle)" Cc: Zi Yan Signed-off-by: Andrew Morton --- diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 9537a61ebae02..271690445a454 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -172,6 +172,7 @@ config PPC select ARCH_STACKWALK select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_DEBUG_PAGEALLOC if PPC_BOOK3S || PPC_8xx + select ARCH_SUPPORTS_PAGE_TABLE_CHECK if !HUGETLB_PAGE select ARCH_SUPPORTS_SCHED_MC if SMP select ARCH_SUPPORTS_SCHED_SMT if PPC64 && SMP select SCHED_MC if ARCH_SUPPORTS_SCHED_MC diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h index 2edca1068b6f3..dcbae85218304 100644 --- a/arch/powerpc/include/asm/book3s/32/pgtable.h +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h @@ -202,6 +202,7 @@ void unmap_kernel_page(unsigned long va); #ifndef __ASSEMBLER__ #include #include +#include /* Bits to mask out from a PGD to get to the PUD page */ #define PGD_MASKED_BITS 0 @@ -315,7 +316,11 @@ static inline int __ptep_test_and_clear_young(struct mm_struct *mm, static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { - return __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0)); + pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0)); + + page_table_check_pte_clear(mm, addr, old_pte); + + return old_pte; } #define __HAVE_ARCH_PTEP_SET_WRPROTECT diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 2d69a827594f3..1a91762b455d9 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -144,6 +144,8 @@ #define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX) #ifndef __ASSEMBLER__ +#include + /* * page table defines */ @@ -416,8 +418,11 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm, static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { - unsigned long old = pte_update(mm, addr, ptep, ~0UL, 0, 0); - return __pte(old); + pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0)); + + page_table_check_pte_clear(mm, addr, old_pte); + + return old_pte; } #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL @@ -426,11 +431,16 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, pte_t *ptep, int full) { if (full && radix_enabled()) { + pte_t old_pte; + /* * We know that this is a full mm pte clear and * hence can be sure there is no parallel set_pte. */ - return radix__ptep_get_and_clear_full(mm, addr, ptep, full); + old_pte = radix__ptep_get_and_clear_full(mm, addr, ptep, full); + page_table_check_pte_clear(mm, addr, old_pte); + + return old_pte; } return ptep_get_and_clear(mm, addr, ptep); } @@ -1301,19 +1311,34 @@ extern int pudp_test_and_clear_young(struct vm_area_struct *vma, static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp) { - if (radix_enabled()) - return radix__pmdp_huge_get_and_clear(mm, addr, pmdp); - return hash__pmdp_huge_get_and_clear(mm, addr, pmdp); + pmd_t old_pmd; + + if (radix_enabled()) { + old_pmd = radix__pmdp_huge_get_and_clear(mm, addr, pmdp); + } else { + old_pmd = hash__pmdp_huge_get_and_clear(mm, addr, pmdp); + } + + page_table_check_pmd_clear(mm, addr, old_pmd); + + return old_pmd; } #define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm, unsigned long addr, pud_t *pudp) { - if (radix_enabled()) - return radix__pudp_huge_get_and_clear(mm, addr, pudp); - BUG(); - return *pudp; + pud_t old_pud; + + if (radix_enabled()) { + old_pud = radix__pudp_huge_get_and_clear(mm, addr, pudp); + } else { + BUG(); + } + + page_table_check_pud_clear(mm, addr, old_pud); + + return old_pud; } static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h index 9bf3e40f27b64..e6da5eaccff63 100644 --- a/arch/powerpc/include/asm/nohash/pgtable.h +++ b/arch/powerpc/include/asm/nohash/pgtable.h @@ -29,6 +29,8 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p #ifndef __ASSEMBLER__ +#include + extern int icache_44x_need_flush; #ifndef pte_huge_size @@ -122,7 +124,11 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { - return __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0)); + pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0)); + + page_table_check_pte_clear(mm, addr, old_pte); + + return old_pte; } #define __HAVE_ARCH_PTEP_GET_AND_CLEAR diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c index 82d31177630b8..ac2a24d15d2e3 100644 --- a/arch/powerpc/mm/book3s64/hash_pgtable.c +++ b/arch/powerpc/mm/book3s64/hash_pgtable.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include @@ -230,6 +231,9 @@ pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long addres pmd = *pmdp; pmd_clear(pmdp); + + page_table_check_pmd_clear(vma->vm_mm, address, pmd); + /* * Wait for all pending hash_page to finish. This is needed * in case of subpage collapse. When we collapse normal pages diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c index 97db2f42ea3d3..4b09c04654a8f 100644 --- a/arch/powerpc/mm/book3s64/pgtable.c +++ b/arch/powerpc/mm/book3s64/pgtable.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include @@ -127,6 +128,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr, WARN_ON(!(pmd_leaf(pmd))); #endif trace_hugepage_set_pmd(addr, pmd_val(pmd)); + page_table_check_pmd_set(mm, addr, pmdp, pmd); return set_pte_at_unchecked(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd)); } @@ -144,6 +146,7 @@ void set_pud_at(struct mm_struct *mm, unsigned long addr, WARN_ON(!(pud_leaf(pud))); #endif trace_hugepage_set_pud(addr, pud_val(pud)); + page_table_check_pud_set(mm, addr, pudp, pud); return set_pte_at_unchecked(mm, addr, pudp_ptep(pudp), pud_pte(pud)); } @@ -179,23 +182,27 @@ void serialize_against_pte_lookup(struct mm_struct *mm) pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { - unsigned long old_pmd; + pmd_t old_pmd; VM_WARN_ON_ONCE(!pmd_present(*pmdp)); - old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID); + old_pmd = __pmd(pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID)); flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); - return __pmd(old_pmd); + page_table_check_pmd_clear(vma->vm_mm, address, old_pmd); + + return old_pmd; } pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address, pud_t *pudp) { - unsigned long old_pud; + pud_t old_pud; VM_WARN_ON_ONCE(!pud_present(*pudp)); - old_pud = pud_hugepage_update(vma->vm_mm, address, pudp, _PAGE_PRESENT, _PAGE_INVALID); + old_pud = __pud(pud_hugepage_update(vma->vm_mm, address, pudp, _PAGE_PRESENT, _PAGE_INVALID)); flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE); - return __pud(old_pud); + page_table_check_pud_clear(vma->vm_mm, address, old_pud); + + return old_pud; } pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma, diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c index b2541bf33d01c..10aced261cff4 100644 --- a/arch/powerpc/mm/book3s64/radix_pgtable.c +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -1474,6 +1475,8 @@ pmd_t radix__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long addre pmd = *pmdp; pmd_clear(pmdp); + page_table_check_pmd_clear(vma->vm_mm, address, pmd); + radix__flush_tlb_collapsed_pmd(vma->vm_mm, address); return pmd; diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c index 7b69cd16e011c..a9be337be3e46 100644 --- a/arch/powerpc/mm/pgtable.c +++ b/arch/powerpc/mm/pgtable.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -206,6 +207,9 @@ void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep, * and not hw_valid ptes. Hence there is no translation cache flush * involved that need to be batched. */ + + page_table_check_ptes_set(mm, addr, ptep, pte, nr); + for (;;) { /*