From: Yang Yanchao <yangyanchao6@huawei.com> euleros inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7WLVX --------------------------------------------- Make sure that the mmap is successfully executed when no device exists. Fixes: 46a7894b5e4c ("mm: gmem: Introduce GMEM") Signed-off-by: Yang Yanchao <yangyanchao6@huawei.com> --- mm/mmap.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index bff71a766e0a..7d04e54494b6 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2453,6 +2453,9 @@ static void munmap_in_peer_devices(struct mm_struct *mm, if (!obj) return; + if (!mm->gm_as) + return; + do { xa_lock(obj->logical_page_table); gm_mapping = vm_object_lookup(obj, addr); @@ -2480,9 +2483,6 @@ static void munmap_in_peer_devices(struct mm_struct *mm, mutex_unlock(&gm_mapping->lock); } while (addr += HPAGE_SIZE, addr != end); - if (!mm->gm_as) - return; - list_for_each_entry_safe(ctx, tmp, &mm->gm_as->gm_ctx_list, gm_as_link) { if (!gm_dev_is_peer(ctx->dev)) continue; @@ -2746,9 +2746,13 @@ static int alloc_va_in_peer_devices(struct mm_struct *mm, gm_context_t *ctx, *tmp; gm_ret_t ret; + if (!mm->gm_as) { + ret = gm_as_create(0, ULONG_MAX, GM_AS_ALLOC_DEFAULT, PAGE_SIZE, + &mm->gm_as); + if (ret) + return ret; + } pr_debug("gmem: start mmap, as %p\n", mm->gm_as); - if (!mm->gm_as) - return -ENODEV; if (!vma->vm_obj) vma->vm_obj = vm_object_create(vma); -- 2.25.1