[PATCH v5 09/17] arm64: pgtable: move pagetable_dtor() to __tlb_remove_table()
From: Qi Zheng <hidden>
Date: 2025-01-08 07:01:35
Also in:
linux-arch, linux-arm-kernel, linux-m68k, linux-mips, linux-mm, linux-riscv, linux-s390, linux-sh, linux-um, lkml, loongarch, sparclinux
Subsystem:
arm64 port (aarch64 architecture), mmu gather and tlb invalidation, the rest · Maintainers:
Catalin Marinas, Will Deacon, "Aneesh Kumar K.V", Andrew Morton, Nick Piggin, Peter Zijlstra, Linus Torvalds
Move pagetable_dtor() to __tlb_remove_table(), 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. Page tables shouldn't have swap cache, so use pagetable_free() instead of free_page_and_swap_cache() to free page table pages. Signed-off-by: Qi Zheng <redacted> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <redacted> Cc: linux-arm-kernel@lists.infradead.org --- arch/arm64/include/asm/tlb.h | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index 408d0f36a8a8f..93591a80b5bfb 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h@@ -9,11 +9,13 @@ #define __ASM_TLB_H #include <linux/pagemap.h> -#include <linux/swap.h> static inline void __tlb_remove_table(void *_table) { - free_page_and_swap_cache((struct page *)_table); + struct ptdesc *ptdesc = (struct ptdesc *)_table; + + pagetable_dtor(ptdesc); + pagetable_free(ptdesc); } #define tlb_flush tlb_flush
@@ -82,7 +84,6 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, { struct ptdesc *ptdesc = page_ptdesc(pte); - pagetable_dtor(ptdesc); tlb_remove_ptdesc(tlb, ptdesc); }
@@ -92,7 +93,6 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, { struct ptdesc *ptdesc = virt_to_ptdesc(pmdp); - pagetable_dtor(ptdesc); tlb_remove_ptdesc(tlb, ptdesc); } #endif
@@ -106,7 +106,6 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp, if (!pgtable_l4_enabled()) return; - pagetable_dtor(ptdesc); tlb_remove_ptdesc(tlb, ptdesc); } #endif
@@ -120,7 +119,6 @@ static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4dp, if (!pgtable_l5_enabled()) return; - pagetable_dtor(ptdesc); tlb_remove_ptdesc(tlb, ptdesc); } #endif
--
2.20.1