Skip to content

Commit 155f043

Browse files
GustavoARSilvarleon
GustavoARSilva
authored and
rleon
committed
RDMA/uverbs: Avoid -Wflex-array-member-not-at-end warnings
-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 <[email protected]> Link: https://lore.kernel.org/r/ZeIgeZ5Sb0IZTOyt@neat Reviewed-by: Kees Cook <[email protected]> Signed-off-by: Leon Romanovsky <[email protected]>
1 parent 6ec429d commit 155f043

File tree

2 files changed

+53
-39
lines changed

2 files changed

+53
-39
lines changed

‎drivers/infiniband/core/uverbs_ioctl.c

Lines changed: 45 additions & 33 deletions
Original file line numberDiff line numberDiff line change
@@ -36,13 +36,15 @@
3636
#include "uverbs.h"
3737

3838
struct bundle_alloc_head {
39-
struct bundle_alloc_head *next;
39+
struct_group_tagged(bundle_alloc_head_hdr, hdr,
40+
struct bundle_alloc_head *next;
41+
);
4042
u8 data[];
4143
};
4244

4345
struct bundle_priv {
4446
/* Must be first */
45-
struct bundle_alloc_head alloc_head;
47+
struct bundle_alloc_head_hdr alloc_head;
4648
struct bundle_alloc_head *allocated_mem;
4749
size_t internal_avail;
4850
size_t internal_used;
@@ -64,7 +66,7 @@ struct bundle_priv {
6466
* Must be last. bundle ends in a flex array which overlaps
6567
* internal_buffer.
6668
*/
67-
struct uverbs_attr_bundle bundle;
69+
struct uverbs_attr_bundle_hdr bundle;
6870
u64 internal_buffer[32];
6971
};
7072

@@ -77,9 +79,10 @@ void uapi_compute_bundle_size(struct uverbs_api_ioctl_method *method_elm,
7779
unsigned int num_attrs)
7880
{
7981
struct bundle_priv *pbundle;
82+
struct uverbs_attr_bundle *bundle;
8083
size_t bundle_size =
8184
offsetof(struct bundle_priv, internal_buffer) +
82-
sizeof(*pbundle->bundle.attrs) * method_elm->key_bitmap_len +
85+
sizeof(*bundle->attrs) * method_elm->key_bitmap_len +
8386
sizeof(*pbundle->uattrs) * num_attrs;
8487

8588
method_elm->use_stack = bundle_size <= sizeof(*pbundle);
@@ -107,7 +110,7 @@ __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
107110
gfp_t flags)
108111
{
109112
struct bundle_priv *pbundle =
110-
container_of(bundle, struct bundle_priv, bundle);
113+
container_of(&bundle->hdr, struct bundle_priv, bundle);
111114
size_t new_used;
112115
void *res;
113116

@@ -149,7 +152,7 @@ static int uverbs_set_output(const struct uverbs_attr_bundle *bundle,
149152
const struct uverbs_attr *attr)
150153
{
151154
struct bundle_priv *pbundle =
152-
container_of(bundle, struct bundle_priv, bundle);
155+
container_of(&bundle->hdr, struct bundle_priv, bundle);
153156
u16 flags;
154157

155158
flags = pbundle->uattrs[attr->ptr_attr.uattr_idx].flags |
@@ -166,6 +169,8 @@ static int uverbs_process_idrs_array(struct bundle_priv *pbundle,
166169
struct ib_uverbs_attr *uattr,
167170
u32 attr_bkey)
168171
{
172+
struct uverbs_attr_bundle *bundle =
173+
container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
169174
const struct uverbs_attr_spec *spec = &attr_uapi->spec;
170175
size_t array_len;
171176
u32 *idr_vals;
@@ -184,7 +189,7 @@ static int uverbs_process_idrs_array(struct bundle_priv *pbundle,
184189
return -EINVAL;
185190

186191
attr->uobjects =
187-
uverbs_alloc(&pbundle->bundle,
192+
uverbs_alloc(bundle,
188193
array_size(array_len, sizeof(*attr->uobjects)));
189194
if (IS_ERR(attr->uobjects))
190195
return PTR_ERR(attr->uobjects);
@@ -209,7 +214,7 @@ static int uverbs_process_idrs_array(struct bundle_priv *pbundle,
209214
for (i = 0; i != array_len; i++) {
210215
attr->uobjects[i] = uverbs_get_uobject_from_file(
211216
spec->u2.objs_arr.obj_type, spec->u2.objs_arr.access,
212-
idr_vals[i], &pbundle->bundle);
217+
idr_vals[i], bundle);
213218
if (IS_ERR(attr->uobjects[i])) {
214219
ret = PTR_ERR(attr->uobjects[i]);
215220
break;
@@ -240,7 +245,9 @@ static int uverbs_process_attr(struct bundle_priv *pbundle,
240245
struct ib_uverbs_attr *uattr, u32 attr_bkey)
241246
{
242247
const struct uverbs_attr_spec *spec = &attr_uapi->spec;
243-
struct uverbs_attr *e = &pbundle->bundle.attrs[attr_bkey];
248+
struct uverbs_attr_bundle *bundle =
249+
container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
250+
struct uverbs_attr *e = &bundle->attrs[attr_bkey];
244251
const struct uverbs_attr_spec *val_spec = spec;
245252
struct uverbs_obj_attr *o_attr;
246253

@@ -288,7 +295,7 @@ static int uverbs_process_attr(struct bundle_priv *pbundle,
288295
if (val_spec->alloc_and_copy && !uverbs_attr_ptr_is_inline(e)) {
289296
void *p;
290297

291-
p = uverbs_alloc(&pbundle->bundle, uattr->len);
298+
p = uverbs_alloc(bundle, uattr->len);
292299
if (IS_ERR(p))
293300
return PTR_ERR(p);
294301

@@ -321,7 +328,7 @@ static int uverbs_process_attr(struct bundle_priv *pbundle,
321328
*/
322329
o_attr->uobject = uverbs_get_uobject_from_file(
323330
spec->u.obj.obj_type, spec->u.obj.access,
324-
uattr->data_s64, &pbundle->bundle);
331+
uattr->data_s64, bundle);
325332
if (IS_ERR(o_attr->uobject))
326333
return PTR_ERR(o_attr->uobject);
327334
__set_bit(attr_bkey, pbundle->uobj_finalize);
@@ -422,6 +429,8 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle,
422429
unsigned int num_attrs)
423430
{
424431
int (*handler)(struct uverbs_attr_bundle *attrs);
432+
struct uverbs_attr_bundle *bundle =
433+
container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
425434
size_t uattrs_size = array_size(sizeof(*pbundle->uattrs), num_attrs);
426435
unsigned int destroy_bkey = pbundle->method_elm->destroy_bkey;
427436
unsigned int i;
@@ -434,7 +443,7 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle,
434443
if (!handler)
435444
return -EIO;
436445

437-
pbundle->uattrs = uverbs_alloc(&pbundle->bundle, uattrs_size);
446+
pbundle->uattrs = uverbs_alloc(bundle, uattrs_size);
438447
if (IS_ERR(pbundle->uattrs))
439448
return PTR_ERR(pbundle->uattrs);
440449
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,
453462
return -EINVAL;
454463

455464
if (pbundle->method_elm->has_udata)
456-
uverbs_fill_udata(&pbundle->bundle,
457-
&pbundle->bundle.driver_udata,
465+
uverbs_fill_udata(bundle, &pbundle->bundle.driver_udata,
458466
UVERBS_ATTR_UHW_IN, UVERBS_ATTR_UHW_OUT);
459467
else
460468
pbundle->bundle.driver_udata = (struct ib_udata){};
461469

462470
if (destroy_bkey != UVERBS_API_ATTR_BKEY_LEN) {
463-
struct uverbs_obj_attr *destroy_attr =
464-
&pbundle->bundle.attrs[destroy_bkey].obj_attr;
471+
struct uverbs_obj_attr *destroy_attr = &bundle->attrs[destroy_bkey].obj_attr;
465472

466-
ret = uobj_destroy(destroy_attr->uobject, &pbundle->bundle);
473+
ret = uobj_destroy(destroy_attr->uobject, bundle);
467474
if (ret)
468475
return ret;
469476
__clear_bit(destroy_bkey, pbundle->uobj_finalize);
470477

471-
ret = handler(&pbundle->bundle);
478+
ret = handler(bundle);
472479
uobj_put_destroy(destroy_attr->uobject);
473480
} else {
474-
ret = handler(&pbundle->bundle);
481+
ret = handler(bundle);
475482
}
476483

477484
/*
@@ -481,10 +488,10 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle,
481488
*/
482489
if (!ret && pbundle->method_elm->has_udata) {
483490
const struct uverbs_attr *attr =
484-
uverbs_attr_get(&pbundle->bundle, UVERBS_ATTR_UHW_OUT);
491+
uverbs_attr_get(bundle, UVERBS_ATTR_UHW_OUT);
485492

486493
if (!IS_ERR(attr))
487-
ret = uverbs_set_output(&pbundle->bundle, attr);
494+
ret = uverbs_set_output(bundle, attr);
488495
}
489496

490497
/*
@@ -501,27 +508,28 @@ static int ib_uverbs_run_method(struct bundle_priv *pbundle,
501508
static void bundle_destroy(struct bundle_priv *pbundle, bool commit)
502509
{
503510
unsigned int key_bitmap_len = pbundle->method_elm->key_bitmap_len;
511+
struct uverbs_attr_bundle *bundle =
512+
container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
504513
struct bundle_alloc_head *memblock;
505514
unsigned int i;
506515

507516
/* fast path for simple uobjects */
508517
i = -1;
509518
while ((i = find_next_bit(pbundle->uobj_finalize, key_bitmap_len,
510519
i + 1)) < key_bitmap_len) {
511-
struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
520+
struct uverbs_attr *attr = &bundle->attrs[i];
512521

513522
uverbs_finalize_object(
514523
attr->obj_attr.uobject,
515524
attr->obj_attr.attr_elm->spec.u.obj.access,
516525
test_bit(i, pbundle->uobj_hw_obj_valid),
517-
commit,
518-
&pbundle->bundle);
526+
commit, bundle);
519527
}
520528

521529
i = -1;
522530
while ((i = find_next_bit(pbundle->spec_finalize, key_bitmap_len,
523531
i + 1)) < key_bitmap_len) {
524-
struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
532+
struct uverbs_attr *attr = &bundle->attrs[i];
525533
const struct uverbs_api_attr *attr_uapi;
526534
void __rcu **slot;
527535

@@ -535,7 +543,7 @@ static void bundle_destroy(struct bundle_priv *pbundle, bool commit)
535543

536544
if (attr_uapi->spec.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
537545
uverbs_free_idrs_array(attr_uapi, &attr->objs_arr_attr,
538-
commit, &pbundle->bundle);
546+
commit, bundle);
539547
}
540548
}
541549

@@ -578,7 +586,8 @@ static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
578586
method_elm->bundle_size -
579587
offsetof(struct bundle_priv, internal_buffer);
580588
pbundle->alloc_head.next = NULL;
581-
pbundle->allocated_mem = &pbundle->alloc_head;
589+
pbundle->allocated_mem = container_of(&pbundle->alloc_head,
590+
struct bundle_alloc_head, hdr);
582591
} else {
583592
pbundle = &onstack;
584593
pbundle->internal_avail = sizeof(pbundle->internal_buffer);
@@ -596,8 +605,9 @@ static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
596605
pbundle->user_attrs = user_attrs;
597606

598607
pbundle->internal_used = ALIGN(pbundle->method_elm->key_bitmap_len *
599-
sizeof(*pbundle->bundle.attrs),
600-
sizeof(*pbundle->internal_buffer));
608+
sizeof(*container_of(&pbundle->bundle,
609+
struct uverbs_attr_bundle, hdr)->attrs),
610+
sizeof(*pbundle->internal_buffer));
601611
memset(pbundle->bundle.attr_present, 0,
602612
sizeof(pbundle->bundle.attr_present));
603613
memset(pbundle->uobj_finalize, 0, sizeof(pbundle->uobj_finalize));
@@ -700,11 +710,13 @@ void uverbs_fill_udata(struct uverbs_attr_bundle *bundle,
700710
unsigned int attr_out)
701711
{
702712
struct bundle_priv *pbundle =
703-
container_of(bundle, struct bundle_priv, bundle);
713+
container_of(&bundle->hdr, struct bundle_priv, bundle);
714+
struct uverbs_attr_bundle *bundle_aux =
715+
container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
704716
const struct uverbs_attr *in =
705-
uverbs_attr_get(&pbundle->bundle, attr_in);
717+
uverbs_attr_get(bundle_aux, attr_in);
706718
const struct uverbs_attr *out =
707-
uverbs_attr_get(&pbundle->bundle, attr_out);
719+
uverbs_attr_get(bundle_aux, attr_out);
708720

709721
if (!IS_ERR(in)) {
710722
udata->inlen = in->ptr_attr.len;
@@ -829,7 +841,7 @@ void uverbs_finalize_uobj_create(const struct uverbs_attr_bundle *bundle,
829841
u16 idx)
830842
{
831843
struct bundle_priv *pbundle =
832-
container_of(bundle, struct bundle_priv, bundle);
844+
container_of(&bundle->hdr, struct bundle_priv, bundle);
833845

834846
__set_bit(uapi_bkey_attr(uapi_key_attr(idx)),
835847
pbundle->uobj_hw_obj_valid);

‎include/rdma/uverbs_ioctl.h

Lines changed: 8 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -629,12 +629,14 @@ struct uverbs_attr {
629629
};
630630

631631
struct uverbs_attr_bundle {
632-
struct ib_udata driver_udata;
633-
struct ib_udata ucore;
634-
struct ib_uverbs_file *ufile;
635-
struct ib_ucontext *context;
636-
struct ib_uobject *uobject;
637-
DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN);
632+
struct_group_tagged(uverbs_attr_bundle_hdr, hdr,
633+
struct ib_udata driver_udata;
634+
struct ib_udata ucore;
635+
struct ib_uverbs_file *ufile;
636+
struct ib_ucontext *context;
637+
struct ib_uobject *uobject;
638+
DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN);
639+
);
638640
struct uverbs_attr attrs[];
639641
};
640642

0 commit comments

Comments
 (0)