Commit 1de9287e authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

RDMA: Add ib_copy_validate_udata_in() 

Add a new function to consolidate the required compatibility pattern for
driver data of checking against a minimum size, and checking for unknown
trailing bytes to be zero into a function.

This new function uses the faster copy_struct_from_user() instead of
trying to directly check for zero.

Incorporate the common ibdev_dbg() logging directly into the error paths
of the helper.

Link: https://patch.msgid.link/r/3-v3-bd56dd443069+49-bnxt_re_uapi_jgg@nvidia.com


Tested-by: default avatarSriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Acked-by: default avatarSriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent b51caeb2

drivers/infiniband/core/rdma_core.h

+3 −0
Original line number Diff line number Diff line
@@ -151,6 +151,9 @@ void uapi_compute_bundle_size(struct uverbs_api_ioctl_method *method_elm, 
			      unsigned int num_attrs);

void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile);



typedef int (*uverbs_api_ioctl_handler_fn)(struct uverbs_attr_bundle *attrs);

uverbs_api_ioctl_handler_fn uverbs_get_handler_fn(struct ib_udata *udata);



extern const struct uapi_definition uverbs_def_obj_async_fd[];

extern const struct uapi_definition uverbs_def_obj_counters[];

extern const struct uapi_definition uverbs_def_obj_cq[];

drivers/infiniband/core/uverbs_ioctl.c

+51 −0
Original line number Diff line number Diff line
@@ -70,6 +70,19 @@ struct bundle_priv { 
	u64 internal_buffer[32];

};



uverbs_api_ioctl_handler_fn uverbs_get_handler_fn(struct ib_udata *udata)

{

	struct uverbs_attr_bundle *bundle =

		rdma_udata_to_uverbs_attr_bundle(udata);

	struct bundle_priv *pbundle =

		container_of(&bundle->hdr, struct bundle_priv, bundle);



	lockdep_assert_held(&bundle->ufile->device->disassociate_srcu);



	return srcu_dereference(pbundle->method_elm->handler,

				&bundle->ufile->device->disassociate_srcu);

}



/*

 * Each method has an absolute minimum amount of memory it needs to allocate,

 * precompute that amount and determine if the onstack memory can be used or
@@ -847,3 +860,41 @@ void uverbs_finalize_uobj_create(const struct uverbs_attr_bundle *bundle, 
		  pbundle->uobj_hw_obj_valid);

}

EXPORT_SYMBOL(uverbs_finalize_uobj_create);



int _ib_copy_validate_udata_in(struct ib_udata *udata, void *req,

			       size_t kernel_size, size_t minimum_size)

{

	int err;



	if (udata->inlen < minimum_size) {

		ibdev_dbg(

			rdma_udata_to_dev(udata),

			"System call driver input udata too small (%zu < %zu) for ioctl %ps called by %pSR\n",

			udata->inlen, minimum_size,

			uverbs_get_handler_fn(udata),

			__builtin_return_address(0));

		return -EINVAL;

	}



	err = copy_struct_from_user(req, kernel_size, udata->inbuf,

				    udata->inlen);

	if (err) {

		if (err == -E2BIG) {

			ibdev_dbg(

				rdma_udata_to_dev(udata),

				"System call driver input udata not zero from %zu -> %zu for ioctl %ps called by %pSR\n",

				minimum_size, udata->inlen,

				uverbs_get_handler_fn(udata),

				__builtin_return_address(0));

			return -EOPNOTSUPP;

		}

		ibdev_dbg(

			rdma_udata_to_dev(udata),

			"System call driver input udata EFAULT for ioctl %ps called by %pSR\n",

			uverbs_get_handler_fn(udata),

			__builtin_return_address(0));

		return err;

	}

	return 0;

}

EXPORT_SYMBOL(_ib_copy_validate_udata_in);

include/rdma/uverbs_ioctl.h

+26 −0
Original line number Diff line number Diff line
@@ -897,6 +897,9 @@ int _uverbs_get_const_unsigned(u64 *to, 
			       size_t idx, u64 upper_bound, u64 *def_val);

int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,

				  size_t idx, const void *from, size_t size);



int _ib_copy_validate_udata_in(struct ib_udata *udata, void *req,

			       size_t kernel_size, size_t minimum_size);

#else

static inline int

uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
@@ -953,6 +956,14 @@ _uverbs_get_const_unsigned(u64 *to, 
{

	return -EINVAL;

}



static inline int _ib_copy_validate_udata_in(struct ib_udata *udata, void *req,

					     size_t kernel_size,

					     size_t minimum_size)

{

	return -EINVAL;

}



#endif



#define uverbs_get_const_signed(_to, _attrs_bundle, _idx)                      \
@@ -1018,4 +1029,19 @@ uverbs_get_raw_fd(int *to, const struct uverbs_attr_bundle *attrs_bundle, 
	return uverbs_get_const_signed(to, attrs_bundle, idx);

}



/**

 * ib_copy_validate_udata_in - Copy and validate that the request structure is

 *                             compatible with this kernel

 * @_udata: The system calls ib_udata struct

 * @_req: The name of an on-stack structure that holds the driver data

 * @_end_member: The member in the struct that is the original end of struct

 *               from the first kernel to introduce it.

 *

 * Check that the udata input request struct is properly formed for this kernel.

 * Then copy it into req

 */

#define ib_copy_validate_udata_in(_udata, _req, _end_member)      \

	_ib_copy_validate_udata_in(_udata, &(_req), sizeof(_req), \

				   offsetofend(typeof(_req), _end_member))



#endif