ascend inclusion category: Feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8LNGH
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Free the user share memory alloced by sp_alloc(). Note that this would unmap the memory for all the processes in the share pool group.
Signed-off-by: Wang Wensheng wangwensheng4@huawei.com --- mm/share_pool.c | 190 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 189 insertions(+), 1 deletion(-)
diff --git a/mm/share_pool.c b/mm/share_pool.c index cb3828ec325c..f05b0f3a8067 100644 --- a/mm/share_pool.c +++ b/mm/share_pool.c @@ -672,12 +672,69 @@ static void spa_dec_usage(struct sp_area *spa) } }
+static void update_mem_usage(unsigned long size, bool inc, bool is_hugepage, + struct sp_group_node *spg_node, enum spa_type type) +{ + switch (type) { + case SPA_TYPE_ALLOC: + update_mem_usage_alloc(size, inc, is_hugepage, spg_node); + break; + case SPA_TYPE_K2TASK: + case SPA_TYPE_K2SPG: + update_mem_usage_k2u(size, inc, spg_node); + break; + default: + WARN(1, "invalid stat type\n"); + } +} + static inline void check_interrupt_context(void) { if (unlikely(in_interrupt())) panic("function can't be used in interrupt context\n"); }
+/* + * Get the sp_group from the mm and return the associated sp_group_node. + * The caller should promise the @mm would not be deleted from the @spg. + */ +static struct sp_group *sp_group_get_from_mm(struct mm_struct *mm, int spg_id, + struct sp_group_node **pnode) +{ + struct sp_group *spg = NULL; + struct sp_group_node *spg_node; + struct sp_group_master *master; + + down_read(&sp_global_sem); + + master = mm->sp_group_master; + if (!master) { + up_read(&sp_global_sem); + return NULL; + } + + if (spg_id == SPG_ID_DEFAULT) { + atomic_inc(&master->local->use_count); + /* There is only one task in the local group */ + *pnode = list_first_entry(&master->local->proc_head, + struct sp_group_node, proc_node); + up_read(&sp_global_sem); + return master->local; + } + + list_for_each_entry(spg_node, &master->group_head, group_node) + if (spg_node->spg->id == spg_id) { + if (atomic_inc_not_zero(&spg_node->spg->use_count)) { + spg = spg_node->spg; + *pnode = spg_node; + } + break; + } + up_read(&sp_global_sem); + + return spg; +} + /** * mp_sp_group_id_by_pid() - Get the sp_group ID array of a process. * @tgid: tgid of target process. @@ -1051,6 +1108,126 @@ void __sp_area_drop(struct vm_area_struct *vma) } }
+/* + * The function calls of do_munmap() won't change any non-atomic member + * of struct sp_group. Please review the following chain: + * do_munmap -> remove_vma_list -> remove_vma -> sp_area_drop -> + * sp_area_free + */ +static void sp_munmap(struct mm_struct *mm, unsigned long addr, + unsigned long size) +{ + int err; + + mmap_write_lock(mm); + if (unlikely(!mmget_not_zero(mm))) { + mmap_write_unlock(mm); + pr_warn("munmap: target mm is exiting\n"); + return; + } + + err = do_munmap(mm, addr, size, NULL); + /* we are not supposed to fail */ + if (err) + pr_err("failed to unmap VA %pK when sp munmap, %d\n", (void *)addr, err); + + mmap_write_unlock(mm); + mmput_async(mm); +} + +/* The caller should hold the write lock for spa->spg->rw_lock */ +static void __sp_free(struct sp_area *spa, struct mm_struct *stop) +{ + struct mm_struct *mm; + struct sp_group_node *spg_node = NULL; + + list_for_each_entry(spg_node, &spa->spg->proc_head, proc_node) { + mm = spg_node->master->mm; + if (mm == stop) + break; + sp_munmap(mm, spa->va_start, spa_size(spa)); + } +} + +/* Free the memory of the backing shmem or hugetlbfs */ +static void sp_fallocate(struct sp_area *spa) +{ + int ret; + unsigned long mode = FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE; + unsigned long offset = addr_offset(spa); + + ret = vfs_fallocate(spa_file(spa), mode, offset, spa_size(spa)); + if (ret) + WARN(1, "sp fallocate failed %d\n", ret); +} + +static struct sp_group *sp_group_get_from_idr(int spg_id) +{ + struct sp_group *spg; + + down_read(&sp_global_sem); + spg = idr_find(&sp_group_idr, spg_id); + if (!spg || !atomic_inc_not_zero(&spg->use_count)) + spg = NULL; + up_read(&sp_global_sem); + + return spg; +} + +static int sp_free_inner(unsigned long addr, int spg_id, bool is_sp_free) +{ + int ret = 0; + struct sp_area *spa; + struct sp_group *spg; + struct sp_group_node *spg_node; + const char *str = is_sp_free ? "sp_free" : "unshare_uva"; + + if (!current->mm) + spg = sp_group_get_from_idr(spg_id); + else + spg = sp_group_get_from_mm(current->mm, spg_id, &spg_node); + if (!spg) { + pr_err("%s, get group failed %d\n", str, spg_id); + return -EINVAL; + } + + down_write(&spg->rw_lock); + spa = sp_area_get(spg, addr); + if (!spa) { + pr_debug("%s, invalid input addr %lx\n", str, addr); + ret = -EINVAL; + goto drop_spg; + } + + if ((is_sp_free && spa->type != SPA_TYPE_ALLOC) || + (!is_sp_free && spa->type == SPA_TYPE_ALLOC)) { + ret = -EINVAL; + pr_warn("%s failed, spa_type is not correct\n", str); + goto drop_spa; + } + + if (!current->mm && spa->applier != current->tgid) { + ret = -EPERM; + pr_err("%s, free a spa allocated by other process(%d), current(%d)\n", + str, spa->applier, current->tgid); + goto drop_spa; + } + + __sp_free(spa, NULL); + if (spa->type == SPA_TYPE_ALLOC) + sp_fallocate(spa); + + if (current->mm) + update_mem_usage(spa_size(spa), false, spa->is_hugepage, spg_node, spa->type); + +drop_spa: + sp_area_put_locked(spa); +drop_spg: + up_write(&spg->rw_lock); + sp_group_put(spg); + return ret; +} + /** * mg_sp_free() - Free the memory allocated by mg_sp_alloc() or * mg_sp_alloc_nodemask(). @@ -1065,7 +1242,15 @@ void __sp_area_drop(struct vm_area_struct *vma) */ int mg_sp_free(unsigned long addr, int id) { - return -EOPNOTSUPP; + if (!sp_is_enabled()) + return -EOPNOTSUPP; + + check_interrupt_context(); + + if (current->flags & PF_KTHREAD) + return -EINVAL; + + return sp_free_inner(addr, id, true); } EXPORT_SYMBOL_GPL(mg_sp_free);
@@ -1527,6 +1712,9 @@ int mg_sp_unshare(unsigned long va, unsigned long size, int spg_id) return -EINVAL;
if (va < TASK_SIZE) { + /* All the spa are aligned to 2M. */ + spg_id = (spg_id == SPG_ID_NONE) ? SPG_ID_DEFAULT : spg_id; + ret = sp_free_inner(ALIGN_DOWN(va, PMD_SIZE), spg_id, false); } else if (va >= PAGE_OFFSET) { /* kernel address */ ret = sp_unshare_kva(va, size);