diff options
| author | Alexandre Ghiti <alexghiti@rivosinc.com> | 2025-09-23 18:25:52 -0600 |
|---|---|---|
| committer | Paul Walmsley <pjw@kernel.org> | 2025-09-23 18:25:52 -0600 |
| commit | 546e42c8c6d9498d5eac14bf2aca0383a11b145a (patch) | |
| tree | 147e012ae5293dcb55aba9b9363032b81789dda5 | |
| parent | riscv: Fix sparse warning about different address spaces (diff) | |
| download | linux-546e42c8c6d9498d5eac14bf2aca0383a11b145a.tar.gz linux-546e42c8c6d9498d5eac14bf2aca0383a11b145a.zip | |
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.
Fixes: c3cc2a4a3a23 ("riscv: Add support for PUD THP")
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20250814-dev-alex-thp_pud_xchg-v1-1-b4704dfae206@rivosinc.com
[pjw@kernel.org: use xchg rather than atomic_long_xchg; avoid atomic op for !CONFIG_SMP like x86]
Signed-off-by: Paul Walmsley <pjw@kernel.org>
| -rw-r--r-- | arch/riscv/include/asm/pgtable.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 91697fbf1f90..815067742939 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -942,6 +942,23 @@ 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) +{ +#ifdef CONFIG_SMP + pud_t pud = __pud(xchg(&pudp->pud, 0)); +#else + pud_t pud = *pudp; + + pud_clear(pudp); +#endif + + page_table_check_pud_clear(mm, pud); + + return pud; +} + static inline int pud_young(pud_t pud) { return pte_young(pud_pte(pud)); |