The patch below does not apply to the 6.17-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.17.y git checkout FETCH_HEAD git cherry-pick -x 668208b161a0b679427e7d0f34c0a65fd7d23979 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025101914-dodge-paprika-36e0@gregkh' --subject-prefix 'PATCH 6.17.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 668208b161a0b679427e7d0f34c0a65fd7d23979 Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti alexghiti@rivosinc.com Date: Thu, 14 Aug 2025 12:06:14 +0000 Subject: [PATCH] riscv: use an atomic xchg in pudp_huge_get_and_clear()
Make sure we return the right pud value and not a value that could have been overwritten in between by a different core.
Link: https://lkml.kernel.org/r/20250814-dev-alex-thp_pud_xchg-v1-1-b4704dfae206@r... Fixes: c3cc2a4a3a23 ("riscv: Add support for PUD THP") Signed-off-by: Alexandre Ghiti alexghiti@rivosinc.com Cc: Andrew Donnellan ajd@linux.ibm.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 91697fbf1f90..e69346307e78 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -942,6 +942,17 @@ static inline int pudp_test_and_clear_young(struct vm_area_struct *vma, return ptep_test_and_clear_young(vma, address, (pte_t *)pudp); }
+#define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR +static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm, + unsigned long address, pud_t *pudp) +{ + pud_t pud = __pud(atomic_long_xchg((atomic_long_t *)pudp, 0)); + + page_table_check_pud_clear(mm, pud); + + return pud; +} + static inline int pud_young(pud_t pud) { return pte_young(pud_pte(pud));