diff options
Diffstat (limited to 'arch/powerpc/mm')
-rw-r--r-- | arch/powerpc/mm/book3s64/mmu_context.c | 55 | ||||
-rw-r--r-- | arch/powerpc/mm/book3s64/pgtable.c | 3 | ||||
-rw-r--r-- | arch/powerpc/mm/mem.c | 3 | ||||
-rw-r--r-- | arch/powerpc/mm/pgtable.c | 16 |
4 files changed, 66 insertions, 11 deletions
diff --git a/arch/powerpc/mm/book3s64/mmu_context.c b/arch/powerpc/mm/book3s64/mmu_context.c index cb2b08635508..6d8f06b04022 100644 --- a/arch/powerpc/mm/book3s64/mmu_context.c +++ b/arch/powerpc/mm/book3s64/mmu_context.c @@ -55,20 +55,52 @@ EXPORT_SYMBOL_GPL(hash__alloc_context_id); void slb_setup_new_exec(void); +static int realloc_context_ids(mm_context_t *ctx) +{ + int i, id; + + /* + * id 0 (aka. ctx->id) is special, we always allocate a new one, even if + * there wasn't one allocated previously (which happens in the exec + * case where ctx is newly allocated). + * + * We have to be a bit careful here. We must keep the existing ids in + * the array, so that we can test if they're non-zero to decide if we + * need to allocate a new one. However in case of error we must free the + * ids we've allocated but *not* any of the existing ones (or risk a + * UAF). That's why we decrement i at the start of the error handling + * loop, to skip the id that we just tested but couldn't reallocate. + */ + for (i = 0; i < ARRAY_SIZE(ctx->extended_id); i++) { + if (i == 0 || ctx->extended_id[i]) { + id = hash__alloc_context_id(); + if (id < 0) + goto error; + + ctx->extended_id[i] = id; + } + } + + /* The caller expects us to return id */ + return ctx->id; + +error: + for (i--; i >= 0; i--) { + if (ctx->extended_id[i]) + ida_free(&mmu_context_ida, ctx->extended_id[i]); + } + + return id; +} + static int hash__init_new_context(struct mm_struct *mm) { int index; - index = hash__alloc_context_id(); - if (index < 0) - return index; - mm->context.hash_context = kmalloc(sizeof(struct hash_mm_context), GFP_KERNEL); - if (!mm->context.hash_context) { - ida_free(&mmu_context_ida, index); + if (!mm->context.hash_context) return -ENOMEM; - } /* * The old code would re-promote on fork, we don't do that when using @@ -96,13 +128,20 @@ static int hash__init_new_context(struct mm_struct *mm) mm->context.hash_context->spt = kmalloc(sizeof(struct subpage_prot_table), GFP_KERNEL); if (!mm->context.hash_context->spt) { - ida_free(&mmu_context_ida, index); kfree(mm->context.hash_context); return -ENOMEM; } } #endif + } + index = realloc_context_ids(&mm->context); + if (index < 0) { +#ifdef CONFIG_PPC_SUBPAGE_PROT + kfree(mm->context.hash_context->spt); +#endif + kfree(mm->context.hash_context); + return index; } pkey_mm_init(mm); diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c index ad3dd977c22d..953850a602f7 100644 --- a/arch/powerpc/mm/book3s64/pgtable.c +++ b/arch/powerpc/mm/book3s64/pgtable.c @@ -116,6 +116,9 @@ pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, /* * This ensures that generic code that rely on IRQ disabling * to prevent a parallel THP split work as expected. + * + * Marking the entry with _PAGE_INVALID && ~_PAGE_PRESENT requires + * a special case check in pmd_access_permitted. */ serialize_against_pte_lookup(vma->vm_mm); return __pmd(old_pmd); diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index e885fe2aafcc..40bd4153ab09 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -253,7 +253,8 @@ void __init paging_init(void) (long int)((top_of_ram - total_ram) >> 20)); #ifdef CONFIG_ZONE_DMA - max_zone_pfns[ZONE_DMA] = min(max_low_pfn, 0x7fffffffUL >> PAGE_SHIFT); + max_zone_pfns[ZONE_DMA] = min(max_low_pfn, + ((1UL << ARCH_ZONE_DMA_BITS) - 1) >> PAGE_SHIFT); #endif max_zone_pfns[ZONE_NORMAL] = max_low_pfn; #ifdef CONFIG_HIGHMEM diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c index db4a6253df92..533fc6fa6726 100644 --- a/arch/powerpc/mm/pgtable.c +++ b/arch/powerpc/mm/pgtable.c @@ -372,13 +372,25 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea, pdshift = PMD_SHIFT; pmdp = pmd_offset(&pud, ea); pmd = READ_ONCE(*pmdp); + /* - * A hugepage collapse is captured by pmd_none, because - * it mark the pmd none and do a hpte invalidate. + * A hugepage collapse is captured by this condition, see + * pmdp_collapse_flush. */ if (pmd_none(pmd)) return NULL; +#ifdef CONFIG_PPC_BOOK3S_64 + /* + * A hugepage split is captured by this condition, see + * pmdp_invalidate. + * + * Huge page modification can be caught here too. + */ + if (pmd_is_serializing(pmd)) + return NULL; +#endif + if (pmd_trans_huge(pmd) || pmd_devmap(pmd)) { if (is_thp) *is_thp = true; |