Commit 65ccffce authored by Kevin Brodsky's avatar Kevin Brodsky Committed by Andrew Morton
Browse files

x86: pgtable: always use pte_free_kernel() 

Page table pages are normally freed using the appropriate helper for the
given page table level.  On x86, pud_free_pmd_page() and
pmd_free_pte_page() are an exception to the rule: they call free_page()
directly.

Constructor/destructor calls are about to be introduced for kernel PTEs. 
To avoid missing dtor calls in those helpers, free the PTE pages using
pte_free_kernel() instead of free_page().

While at it also use pmd_free() instead of calling pagetable_dtor()
explicitly at the PMD level.

Link: https://lkml.kernel.org/r/20250408095222.860601-3-kevin.brodsky@arm.com


Signed-off-by: default avatarKevin Brodsky <kevin.brodsky@arm.com>
Acked-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linus Waleij <linus.walleij@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: <x86@kernel.org>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent d82d3bf4

arch/x86/mm/pgtable.c

+3 −4
Original line number Diff line number Diff line
@@ -809,14 +809,13 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr) 
	for (i = 0; i < PTRS_PER_PMD; i++) {

		if (!pmd_none(pmd_sv[i])) {

			pte = (pte_t *)pmd_page_vaddr(pmd_sv[i]);

			free_page((unsigned long)pte);

			pte_free_kernel(&init_mm, pte);

		}

	}



	free_page((unsigned long)pmd_sv);



	pagetable_dtor(virt_to_ptdesc(pmd));

	free_page((unsigned long)pmd);

	pmd_free(&init_mm, pmd);



	return 1;

}
@@ -839,7 +838,7 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) 
	/* INVLPG to clear all paging-structure caches */

	flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1);



	free_page((unsigned long)pte);

	pte_free_kernel(&init_mm, pte);



	return 1;

}