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authorQi Zheng <zhengqi.arch@bytedance.com>2025-01-08 14:57:23 +0800
committerAndrew Morton <akpm@linux-foundation.org>2025-01-25 20:22:22 -0800
commitdb6b435d731a8d82c38e558175db55466cb5832a (patch)
tree6ad4b763d825245c7cd99ae9af18fb8c2fc29e13 /arch/um/include/asm
parentb7dcd539bfc7301b56fdaa6ebbb23752b670ee81 (diff)
mm: pgtable: introduce pagetable_dtor()
The pagetable_p*_dtor() are exactly the same except for the handling of ptlock. If we make ptlock_free() handle the case where ptdesc->ptl is NULL and remove VM_BUG_ON_PAGE() from pmd_ptlock_free(), we can unify pagetable_p*_dtor() into one function. Let's introduce pagetable_dtor() to do this. Later, pagetable_dtor() will be moved to tlb_remove_ptdesc(), so that ptlock and page table pages can be freed together (regardless of whether RCU is used). This prevents the use-after-free problem where the ptlock is freed immediately but the page table pages is freed later via RCU. Link: https://lkml.kernel.org/r/47f44fff9dc68d9d9e9a0d6c036df275f820598a.1736317725.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/um/include/asm')
-rw-r--r--arch/um/include/asm/pgalloc.h6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
index 04fb4e6969a4..f0af23c3aeb2 100644
--- a/arch/um/include/asm/pgalloc.h
+++ b/arch/um/include/asm/pgalloc.h
@@ -27,7 +27,7 @@ extern pgd_t *pgd_alloc(struct mm_struct *);
#define __pte_free_tlb(tlb, pte, address) \
do { \
- pagetable_pte_dtor(page_ptdesc(pte)); \
+ pagetable_dtor(page_ptdesc(pte)); \
tlb_remove_page_ptdesc((tlb), (page_ptdesc(pte))); \
} while (0)
@@ -35,7 +35,7 @@ do { \
#define __pmd_free_tlb(tlb, pmd, address) \
do { \
- pagetable_pmd_dtor(virt_to_ptdesc(pmd)); \
+ pagetable_dtor(virt_to_ptdesc(pmd)); \
tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pmd)); \
} while (0)
@@ -43,7 +43,7 @@ do { \
#define __pud_free_tlb(tlb, pud, address) \
do { \
- pagetable_pud_dtor(virt_to_ptdesc(pud)); \
+ pagetable_dtor(virt_to_ptdesc(pud)); \
tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pud)); \
} while (0)