6.17-stable review patch. If anyone has any objections, please let me know.
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From: Alexandre Ghiti alexghiti@rivosinc.com
commit 668208b161a0b679427e7d0f34c0a65fd7d23979 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/riscv/include/asm/pgtable.h | 11 +++++++++++ 1 file changed, 11 insertions(+)
--- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -959,6 +959,17 @@ static inline pud_t pudp_huge_get_and_cl return pud; }
+#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));