From patchwork Fri Mar 1 18:37:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. 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R. Silva" To: Jason Gunthorpe , Leon Romanovsky Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org, Kees Cook Subject: [PATCH][next] RDMA/uverbs: Avoid -Wflex-array-member-not-at-end warnings Message-ID: Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting ready to enable it globally. There are currently a couple of objects (`alloc_head` and `bundle`) in `struct bundle_priv` that contain a couple of flexible structures: struct bundle_priv { /* Must be first */ struct bundle_alloc_head alloc_head; ... /* * Must be last. bundle ends in a flex array which overlaps * internal_buffer. */ struct uverbs_attr_bundle bundle; u64 internal_buffer[32]; }; So, in order to avoid ending up with a couple of flexible-array members in the middle of a struct, we use the `struct_group_tagged()` helper to separate the flexible array from the rest of the members in the flexible structures: struct uverbs_attr_bundle { struct_group_tagged(uverbs_attr_bundle_hdr, hdr, ... the rest of the members ); struct uverbs_attr attrs[]; }; With the change described above, we now declare objects of the type of the tagged struct without embedding flexible arrays in the middle of another struct: struct bundle_priv { /* Must be first */ struct bundle_alloc_head_hdr alloc_head; ... struct uverbs_attr_bundle_hdr bundle; u64 internal_buffer[32]; }; We also use `container_of()` whenever we need to retrieve a pointer to the flexible structures. Notice that the `bundle_size` computed in `uapi_compute_bundle_size()` remains the same. So, with these changes, fix the following warnings: drivers/infiniband/core/uverbs_ioctl.c:45:34: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] 45 | struct bundle_alloc_head alloc_head; | ^~~~~~~~~~ drivers/infiniband/core/uverbs_ioctl.c:67:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] 67 | struct uverbs_attr_bundle bundle; | ^~~~~~ Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook --- drivers/infiniband/core/uverbs_ioctl.c | 78 +++++++++++++++----------- include/rdma/uverbs_ioctl.h | 14 +++-- 2 files changed, 53 insertions(+), 39 deletions(-) diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c index d9799706c58e..f80da6a67e24 100644 --- a/drivers/infiniband/core/uverbs_ioctl.c +++ b/drivers/infiniband/core/uverbs_ioctl.c @@ -36,13 +36,15 @@ #include "uverbs.h" struct bundle_alloc_head { - struct bundle_alloc_head *next; + struct_group_tagged(bundle_alloc_head_hdr, hdr, + struct bundle_alloc_head *next; + ); u8 data[]; }; struct bundle_priv { /* Must be first */ - struct bundle_alloc_head alloc_head; + struct bundle_alloc_head_hdr alloc_head; struct bundle_alloc_head *allocated_mem; size_t internal_avail; size_t internal_used; @@ -64,7 +66,7 @@ struct bundle_priv { * Must be last. bundle ends in a flex array which overlaps * internal_buffer. */ - struct uverbs_attr_bundle bundle; + struct uverbs_attr_bundle_hdr bundle; u64 internal_buffer[32]; }; @@ -77,9 +79,10 @@ void uapi_compute_bundle_size(struct uverbs_api_ioctl_method *method_elm, unsigned int num_attrs) { struct bundle_priv *pbundle; + struct uverbs_attr_bundle *bundle; size_t bundle_size = offsetof(struct bundle_priv, internal_buffer) + - sizeof(*pbundle->bundle.attrs) * method_elm->key_bitmap_len + + sizeof(*bundle->attrs) * method_elm->key_bitmap_len + sizeof(*pbundle->uattrs) * num_attrs; method_elm->use_stack = bundle_size <= sizeof(*pbundle); @@ -107,7 +110,7 @@ __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size, gfp_t flags) { struct bundle_priv *pbundle = - container_of(bundle, struct bundle_priv, bundle); + container_of(&bundle->hdr, struct bundle_priv, bundle); size_t new_used; void *res; @@ -149,7 +152,7 @@ static int uverbs_set_output(const struct uverbs_attr_bundle *bundle, const struct uverbs_attr *attr) { struct bundle_priv *pbundle = - container_of(bundle, struct bundle_priv, bundle); + container_of(&bundle->hdr, struct bundle_priv, bundle); u16 flags; flags = pbundle->uattrs[attr->ptr_attr.uattr_idx].flags | @@ -166,6 +169,8 @@ static int uverbs_process_idrs_array(struct bundle_priv *pbundle, struct ib_uverbs_attr *uattr, u32 attr_bkey) { + struct uverbs_attr_bundle *bundle = + container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr); const struct uverbs_attr_spec *spec = &attr_uapi->spec; size_t array_len; u32 *idr_vals; @@ -184,7 +189,7 @@ static int uverbs_process_idrs_array(struct bundle_priv *pbundle, return -EINVAL; attr->uobjects = - uverbs_alloc(&pbundle->bundle, + uverbs_alloc(bundle, array_size(array_len, sizeof(*attr->uobjects))); if (IS_ERR(attr->uobjects)) return PTR_ERR(attr->uobjects); @@ -209,7 +214,7 @@ static int uverbs_process_idrs_array(struct bundle_priv *pbundle, for (i = 0; i != array_len; i++) { attr->uobjects[i] = uverbs_get_uobject_from_file( spec->u2.objs_arr.obj_type, spec->u2.objs_arr.access, - idr_vals[i], &pbundle->bundle); + idr_vals[i], bundle); if (IS_ERR(attr->uobjects[i])) { ret = PTR_ERR(attr->uobjects[i]); break; @@ -240,7 +245,9 @@ static int uverbs_process_attr(struct bundle_priv *pbundle, struct ib_uverbs_attr *uattr, u32 attr_bkey) { const struct uverbs_attr_spec *spec = &attr_uapi->spec; - struct uverbs_attr *e = &pbundle->bundle.attrs[attr_bkey]; + struct uverbs_attr_bundle *bundle = + container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr); + struct uverbs_attr *e = &bundle->attrs[attr_bkey]; const struct uverbs_attr_spec *val_spec = spec; struct uverbs_obj_attr *o_attr; @@ -288,7 +295,7 @@ static int uverbs_process_attr(struct bundle_priv *pbundle, if (val_spec->alloc_and_copy && !uverbs_attr_ptr_is_inline(e)) { void *p; - p = uverbs_alloc(&pbundle->bundle, uattr->len); + p = uverbs_alloc(bundle, uattr->len); if (IS_ERR(p)) return PTR_ERR(p); @@ -321,7 +328,7 @@ static int uverbs_process_attr(struct bundle_priv *pbundle, */ o_attr->uobject = uverbs_get_uobject_from_file( spec->u.obj.obj_type, spec->u.obj.access, - uattr->data_s64, &pbundle->bundle); + uattr->data_s64, bundle); if (IS_ERR(o_attr->uobject)) return PTR_ERR(o_attr->uobject); __set_bit(attr_bkey, pbundle->uobj_finalize); @@ -422,6 +429,8 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle, unsigned int num_attrs) { int (*handler)(struct uverbs_attr_bundle *attrs); + struct uverbs_attr_bundle *bundle = + container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr); size_t uattrs_size = array_size(sizeof(*pbundle->uattrs), num_attrs); unsigned int destroy_bkey = pbundle->method_elm->destroy_bkey; unsigned int i; @@ -434,7 +443,7 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle, if (!handler) return -EIO; - pbundle->uattrs = uverbs_alloc(&pbundle->bundle, uattrs_size); + pbundle->uattrs = uverbs_alloc(bundle, uattrs_size); if (IS_ERR(pbundle->uattrs)) return PTR_ERR(pbundle->uattrs); if (copy_from_user(pbundle->uattrs, pbundle->user_attrs, uattrs_size)) @@ -453,25 +462,23 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle, return -EINVAL; if (pbundle->method_elm->has_udata) - uverbs_fill_udata(&pbundle->bundle, - &pbundle->bundle.driver_udata, + uverbs_fill_udata(bundle, &pbundle->bundle.driver_udata, UVERBS_ATTR_UHW_IN, UVERBS_ATTR_UHW_OUT); else pbundle->bundle.driver_udata = (struct ib_udata){}; if (destroy_bkey != UVERBS_API_ATTR_BKEY_LEN) { - struct uverbs_obj_attr *destroy_attr = - &pbundle->bundle.attrs[destroy_bkey].obj_attr; + struct uverbs_obj_attr *destroy_attr = &bundle->attrs[destroy_bkey].obj_attr; - ret = uobj_destroy(destroy_attr->uobject, &pbundle->bundle); + ret = uobj_destroy(destroy_attr->uobject, bundle); if (ret) return ret; __clear_bit(destroy_bkey, pbundle->uobj_finalize); - ret = handler(&pbundle->bundle); + ret = handler(bundle); uobj_put_destroy(destroy_attr->uobject); } else { - ret = handler(&pbundle->bundle); + ret = handler(bundle); } /* @@ -481,10 +488,10 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle, */ if (!ret && pbundle->method_elm->has_udata) { const struct uverbs_attr *attr = - uverbs_attr_get(&pbundle->bundle, UVERBS_ATTR_UHW_OUT); + uverbs_attr_get(bundle, UVERBS_ATTR_UHW_OUT); if (!IS_ERR(attr)) - ret = uverbs_set_output(&pbundle->bundle, attr); + ret = uverbs_set_output(bundle, attr); } /* @@ -501,6 +508,8 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle, static void bundle_destroy(struct bundle_priv *pbundle, bool commit) { unsigned int key_bitmap_len = pbundle->method_elm->key_bitmap_len; + struct uverbs_attr_bundle *bundle = + container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr); struct bundle_alloc_head *memblock; unsigned int i; @@ -508,20 +517,19 @@ static void bundle_destroy(struct bundle_priv *pbundle, bool commit) i = -1; while ((i = find_next_bit(pbundle->uobj_finalize, key_bitmap_len, i + 1)) < key_bitmap_len) { - struct uverbs_attr *attr = &pbundle->bundle.attrs[i]; + struct uverbs_attr *attr = &bundle->attrs[i]; uverbs_finalize_object( attr->obj_attr.uobject, attr->obj_attr.attr_elm->spec.u.obj.access, test_bit(i, pbundle->uobj_hw_obj_valid), - commit, - &pbundle->bundle); + commit, bundle); } i = -1; while ((i = find_next_bit(pbundle->spec_finalize, key_bitmap_len, i + 1)) < key_bitmap_len) { - struct uverbs_attr *attr = &pbundle->bundle.attrs[i]; + struct uverbs_attr *attr = &bundle->attrs[i]; const struct uverbs_api_attr *attr_uapi; void __rcu **slot; @@ -535,7 +543,7 @@ static void bundle_destroy(struct bundle_priv *pbundle, bool commit) if (attr_uapi->spec.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) { uverbs_free_idrs_array(attr_uapi, &attr->objs_arr_attr, - commit, &pbundle->bundle); + commit, bundle); } } @@ -578,7 +586,8 @@ static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile, method_elm->bundle_size - offsetof(struct bundle_priv, internal_buffer); pbundle->alloc_head.next = NULL; - pbundle->allocated_mem = &pbundle->alloc_head; + pbundle->allocated_mem = container_of(&pbundle->alloc_head, + struct bundle_alloc_head, hdr); } else { pbundle = &onstack; pbundle->internal_avail = sizeof(pbundle->internal_buffer); @@ -596,8 +605,9 @@ static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile, pbundle->user_attrs = user_attrs; pbundle->internal_used = ALIGN(pbundle->method_elm->key_bitmap_len * - sizeof(*pbundle->bundle.attrs), - sizeof(*pbundle->internal_buffer)); + sizeof(*container_of(&pbundle->bundle, + struct uverbs_attr_bundle, hdr)->attrs), + sizeof(*pbundle->internal_buffer)); memset(pbundle->bundle.attr_present, 0, sizeof(pbundle->bundle.attr_present)); memset(pbundle->uobj_finalize, 0, sizeof(pbundle->uobj_finalize)); @@ -700,11 +710,13 @@ void uverbs_fill_udata(struct uverbs_attr_bundle *bundle, unsigned int attr_out) { struct bundle_priv *pbundle = - container_of(bundle, struct bundle_priv, bundle); + container_of(&bundle->hdr, struct bundle_priv, bundle); + struct uverbs_attr_bundle *bundle_aux = + container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr); const struct uverbs_attr *in = - uverbs_attr_get(&pbundle->bundle, attr_in); + uverbs_attr_get(bundle_aux, attr_in); const struct uverbs_attr *out = - uverbs_attr_get(&pbundle->bundle, attr_out); + uverbs_attr_get(bundle_aux, attr_out); if (!IS_ERR(in)) { udata->inlen = in->ptr_attr.len; @@ -829,7 +841,7 @@ void uverbs_finalize_uobj_create(const struct uverbs_attr_bundle *bundle, u16 idx) { struct bundle_priv *pbundle = - container_of(bundle, struct bundle_priv, bundle); + container_of(&bundle->hdr, struct bundle_priv, bundle); __set_bit(uapi_bkey_attr(uapi_key_attr(idx)), pbundle->uobj_hw_obj_valid); diff --git a/include/rdma/uverbs_ioctl.h b/include/rdma/uverbs_ioctl.h index 06287de69cd2..e6c0de227fad 100644 --- a/include/rdma/uverbs_ioctl.h +++ b/include/rdma/uverbs_ioctl.h @@ -629,12 +629,14 @@ struct uverbs_attr { }; struct uverbs_attr_bundle { - struct ib_udata driver_udata; - struct ib_udata ucore; - struct ib_uverbs_file *ufile; - struct ib_ucontext *context; - struct ib_uobject *uobject; - DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN); + struct_group_tagged(uverbs_attr_bundle_hdr, hdr, + struct ib_udata driver_udata; + struct ib_udata ucore; + struct ib_uverbs_file *ufile; + struct ib_ucontext *context; + struct ib_uobject *uobject; + DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN); + ); struct uverbs_attr attrs[]; };