sugar/linux
1
0
Fork 0
Code Activity

riscv: use an atomic xchg in pudp_huge_get_and_clear()

Browse Source 
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@rivosinc.com
Fixes: c3cc2a4a3a ("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>
This commit is contained in:
Alexandre Ghiti
2025-08-14 12:06:14 +00:00
committed by Andrew Morton
parent 0ee8279828
commit 668208b161
1 changed files with 11 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
arch/riscv/include/asm/pgtable.h
View File

@@ -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));