From: Gerald Schaefer gerald.schaefer@de.ibm.com
[ Upstream commit 2416cefc504ba8ae9b17e3e6b40afc72708f96be ]
Unlike pxd_free_tlb(), the pxd_free() functions do not check for folded page tables. This is not an issue so far, as those functions will actually never be called, since no code will reach them when page tables are folded.
In order to avoid future issues, and to make the s390 code more similar to other architectures, add mm_pxd_folded() checks, similar to how it is done in pxd_free_tlb().
This was found by testing a patch from from Anshuman Khandual, which is currently discussed on LKML ("mm/debug: Add tests validating architecture page table helpers").
Signed-off-by: Gerald Schaefer gerald.schaefer@de.ibm.com Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/s390/include/asm/pgalloc.h | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h index bbe99cb8219d..11857fea993c 100644 --- a/arch/s390/include/asm/pgalloc.h +++ b/arch/s390/include/asm/pgalloc.h @@ -70,7 +70,12 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long address) crst_table_init(table, _REGION2_ENTRY_EMPTY); return (p4d_t *) table; } -#define p4d_free(mm, p4d) crst_table_free(mm, (unsigned long *) p4d) + +static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d) +{ + if (!mm_p4d_folded(mm)) + crst_table_free(mm, (unsigned long *) p4d); +}
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address) { @@ -79,7 +84,12 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address) crst_table_init(table, _REGION3_ENTRY_EMPTY); return (pud_t *) table; } -#define pud_free(mm, pud) crst_table_free(mm, (unsigned long *) pud) + +static inline void pud_free(struct mm_struct *mm, pud_t *pud) +{ + if (!mm_pud_folded(mm)) + crst_table_free(mm, (unsigned long *) pud); +}
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr) { @@ -97,6 +107,8 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd) { + if (mm_pmd_folded(mm)) + return; pgtable_pmd_page_dtor(virt_to_page(pmd)); crst_table_free(mm, (unsigned long *) pmd); }