[PATCH v3 08/17] arm: pgtable: move pagetable_dtor() to __tlb_remove_table()
From: Qi Zheng <hidden>
Date: 2024-12-23 09:44:45
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:
arm port, mmu gather and tlb invalidation, the rest · Maintainers:
Russell King, 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> Cc: linux-arm-kernel@lists.infradead.org --- arch/arm/include/asm/tlb.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index ef79bf1e8563f..264ab635e807a 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h@@ -26,12 +26,14 @@ #else /* !CONFIG_MMU */ -#include <linux/swap.h> #include <asm/tlbflush.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); } #include <asm-generic/tlb.h>
@@ -41,8 +43,6 @@ __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr) { struct ptdesc *ptdesc = page_ptdesc(pte); - pagetable_dtor(ptdesc); - #ifndef CONFIG_ARM_LPAE /* * With the classic ARM MMU, a pte page has two corresponding pmd
@@ -61,7 +61,6 @@ __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr) #ifdef CONFIG_ARM_LPAE struct ptdesc *ptdesc = virt_to_ptdesc(pmdp); - pagetable_dtor(ptdesc); tlb_remove_ptdesc(tlb, ptdesc); #endif }
--
2.20.1