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IB/uverbs: Remove the ib_uverbs_attr pointer from each attr

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Memory in the bundle is valuable, do not waste it holding an 8 byte
pointer for the rare case of writing to a PTR_OUT. We can compute the
pointer by storing a small 1 byte array offset and the base address of the
uattr memory in the bundle private memory.

This also means we can access the kernel's copy of the ib_uverbs_attr, so
drop the copy of flags as well.

Since the uattr base should be private bundle information this also
de-inlines the already too big uverbs_copy_to inline and moves
create_udata into uverbs_ioctl.c so they can see the private struct
definition.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
This commit is contained in:
Jason Gunthorpe
2018-08-09 20:14:39 -06:00
parent 4b3dd2bbf0
commit 6a1f444fef
3 changed files with 72 additions and 63 deletions
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36
include/rdma/uverbs_ioctl.h
View File

@@ -461,8 +461,7 @@ struct uverbs_ptr_attr {
u64 data;
};
u16 len;
/* Combination of bits from enum UVERBS_ATTR_F_XXXX */
u16 flags;
u16 uattr_idx;
u8 enum_id;
};
@@ -471,11 +470,6 @@ struct uverbs_obj_attr {
};
struct uverbs_attr {
/*
* pointer to the user-space given attribute, in order to write the
* new uobject's id or update flags.
*/
struct ib_uverbs_attr __user *uattr;
union {
struct uverbs_ptr_attr ptr_attr;
struct uverbs_obj_attr obj_attr;
@@ -575,27 +569,6 @@ uverbs_attr_get_len(const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
return attr->ptr_attr.len;
}
static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, const void *from, size_t size)
{
const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
u16 flags;
size_t min_size;
if (IS_ERR(attr))
return PTR_ERR(attr);
min_size = min_t(size_t, attr->ptr_attr.len, size);
if (copy_to_user(u64_to_user_ptr(attr->ptr_attr.data), from, min_size))
return -EFAULT;
flags = attr->ptr_attr.flags | UVERBS_ATTR_F_VALID_OUTPUT;
if (put_user(flags, &attr->uattr->flags))
return -EFAULT;
return 0;
}
static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
{
return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
@@ -676,6 +649,8 @@ int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, u64 allowed_bits);
int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, u64 allowed_bits);
int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle, size_t idx,
const void *from, size_t size);
#else
static inline int
uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
@@ -689,6 +664,11 @@ uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
{
return -EINVAL;
}
static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
size_t idx, const void *from, size_t size)
{
return -EINVAL;
}
#endif
/* =================================================