mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 23:53:55 +08:00
741 lines
17 KiB
C
741 lines
17 KiB
C
#include <linux/export.h>
|
|
#include <linux/uio.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <net/checksum.h>
|
|
|
|
#define iterate_iovec(i, n, __v, __p, skip, STEP) { \
|
|
size_t left; \
|
|
size_t wanted = n; \
|
|
__p = i->iov; \
|
|
__v.iov_len = min(n, __p->iov_len - skip); \
|
|
if (likely(__v.iov_len)) { \
|
|
__v.iov_base = __p->iov_base + skip; \
|
|
left = (STEP); \
|
|
__v.iov_len -= left; \
|
|
skip += __v.iov_len; \
|
|
n -= __v.iov_len; \
|
|
} else { \
|
|
left = 0; \
|
|
} \
|
|
while (unlikely(!left && n)) { \
|
|
__p++; \
|
|
__v.iov_len = min(n, __p->iov_len); \
|
|
if (unlikely(!__v.iov_len)) \
|
|
continue; \
|
|
__v.iov_base = __p->iov_base; \
|
|
left = (STEP); \
|
|
__v.iov_len -= left; \
|
|
skip = __v.iov_len; \
|
|
n -= __v.iov_len; \
|
|
} \
|
|
n = wanted - n; \
|
|
}
|
|
|
|
#define iterate_kvec(i, n, __v, __p, skip, STEP) { \
|
|
size_t wanted = n; \
|
|
__p = i->kvec; \
|
|
__v.iov_len = min(n, __p->iov_len - skip); \
|
|
if (likely(__v.iov_len)) { \
|
|
__v.iov_base = __p->iov_base + skip; \
|
|
(void)(STEP); \
|
|
skip += __v.iov_len; \
|
|
n -= __v.iov_len; \
|
|
} \
|
|
while (unlikely(n)) { \
|
|
__p++; \
|
|
__v.iov_len = min(n, __p->iov_len); \
|
|
if (unlikely(!__v.iov_len)) \
|
|
continue; \
|
|
__v.iov_base = __p->iov_base; \
|
|
(void)(STEP); \
|
|
skip = __v.iov_len; \
|
|
n -= __v.iov_len; \
|
|
} \
|
|
n = wanted; \
|
|
}
|
|
|
|
#define iterate_bvec(i, n, __v, __p, skip, STEP) { \
|
|
size_t wanted = n; \
|
|
__p = i->bvec; \
|
|
__v.bv_len = min_t(size_t, n, __p->bv_len - skip); \
|
|
if (likely(__v.bv_len)) { \
|
|
__v.bv_page = __p->bv_page; \
|
|
__v.bv_offset = __p->bv_offset + skip; \
|
|
(void)(STEP); \
|
|
skip += __v.bv_len; \
|
|
n -= __v.bv_len; \
|
|
} \
|
|
while (unlikely(n)) { \
|
|
__p++; \
|
|
__v.bv_len = min_t(size_t, n, __p->bv_len); \
|
|
if (unlikely(!__v.bv_len)) \
|
|
continue; \
|
|
__v.bv_page = __p->bv_page; \
|
|
__v.bv_offset = __p->bv_offset; \
|
|
(void)(STEP); \
|
|
skip = __v.bv_len; \
|
|
n -= __v.bv_len; \
|
|
} \
|
|
n = wanted; \
|
|
}
|
|
|
|
#define iterate_all_kinds(i, n, v, I, B, K) { \
|
|
size_t skip = i->iov_offset; \
|
|
if (unlikely(i->type & ITER_BVEC)) { \
|
|
const struct bio_vec *bvec; \
|
|
struct bio_vec v; \
|
|
iterate_bvec(i, n, v, bvec, skip, (B)) \
|
|
} else if (unlikely(i->type & ITER_KVEC)) { \
|
|
const struct kvec *kvec; \
|
|
struct kvec v; \
|
|
iterate_kvec(i, n, v, kvec, skip, (K)) \
|
|
} else { \
|
|
const struct iovec *iov; \
|
|
struct iovec v; \
|
|
iterate_iovec(i, n, v, iov, skip, (I)) \
|
|
} \
|
|
}
|
|
|
|
#define iterate_and_advance(i, n, v, I, B, K) { \
|
|
size_t skip = i->iov_offset; \
|
|
if (unlikely(i->type & ITER_BVEC)) { \
|
|
const struct bio_vec *bvec; \
|
|
struct bio_vec v; \
|
|
iterate_bvec(i, n, v, bvec, skip, (B)) \
|
|
if (skip == bvec->bv_len) { \
|
|
bvec++; \
|
|
skip = 0; \
|
|
} \
|
|
i->nr_segs -= bvec - i->bvec; \
|
|
i->bvec = bvec; \
|
|
} else if (unlikely(i->type & ITER_KVEC)) { \
|
|
const struct kvec *kvec; \
|
|
struct kvec v; \
|
|
iterate_kvec(i, n, v, kvec, skip, (K)) \
|
|
if (skip == kvec->iov_len) { \
|
|
kvec++; \
|
|
skip = 0; \
|
|
} \
|
|
i->nr_segs -= kvec - i->kvec; \
|
|
i->kvec = kvec; \
|
|
} else { \
|
|
const struct iovec *iov; \
|
|
struct iovec v; \
|
|
iterate_iovec(i, n, v, iov, skip, (I)) \
|
|
if (skip == iov->iov_len) { \
|
|
iov++; \
|
|
skip = 0; \
|
|
} \
|
|
i->nr_segs -= iov - i->iov; \
|
|
i->iov = iov; \
|
|
} \
|
|
i->count -= n; \
|
|
i->iov_offset = skip; \
|
|
}
|
|
|
|
static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
|
|
struct iov_iter *i)
|
|
{
|
|
size_t skip, copy, left, wanted;
|
|
const struct iovec *iov;
|
|
char __user *buf;
|
|
void *kaddr, *from;
|
|
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
wanted = bytes;
|
|
iov = i->iov;
|
|
skip = i->iov_offset;
|
|
buf = iov->iov_base + skip;
|
|
copy = min(bytes, iov->iov_len - skip);
|
|
|
|
if (!fault_in_pages_writeable(buf, copy)) {
|
|
kaddr = kmap_atomic(page);
|
|
from = kaddr + offset;
|
|
|
|
/* first chunk, usually the only one */
|
|
left = __copy_to_user_inatomic(buf, from, copy);
|
|
copy -= left;
|
|
skip += copy;
|
|
from += copy;
|
|
bytes -= copy;
|
|
|
|
while (unlikely(!left && bytes)) {
|
|
iov++;
|
|
buf = iov->iov_base;
|
|
copy = min(bytes, iov->iov_len);
|
|
left = __copy_to_user_inatomic(buf, from, copy);
|
|
copy -= left;
|
|
skip = copy;
|
|
from += copy;
|
|
bytes -= copy;
|
|
}
|
|
if (likely(!bytes)) {
|
|
kunmap_atomic(kaddr);
|
|
goto done;
|
|
}
|
|
offset = from - kaddr;
|
|
buf += copy;
|
|
kunmap_atomic(kaddr);
|
|
copy = min(bytes, iov->iov_len - skip);
|
|
}
|
|
/* Too bad - revert to non-atomic kmap */
|
|
kaddr = kmap(page);
|
|
from = kaddr + offset;
|
|
left = __copy_to_user(buf, from, copy);
|
|
copy -= left;
|
|
skip += copy;
|
|
from += copy;
|
|
bytes -= copy;
|
|
while (unlikely(!left && bytes)) {
|
|
iov++;
|
|
buf = iov->iov_base;
|
|
copy = min(bytes, iov->iov_len);
|
|
left = __copy_to_user(buf, from, copy);
|
|
copy -= left;
|
|
skip = copy;
|
|
from += copy;
|
|
bytes -= copy;
|
|
}
|
|
kunmap(page);
|
|
done:
|
|
if (skip == iov->iov_len) {
|
|
iov++;
|
|
skip = 0;
|
|
}
|
|
i->count -= wanted - bytes;
|
|
i->nr_segs -= iov - i->iov;
|
|
i->iov = iov;
|
|
i->iov_offset = skip;
|
|
return wanted - bytes;
|
|
}
|
|
|
|
static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes,
|
|
struct iov_iter *i)
|
|
{
|
|
size_t skip, copy, left, wanted;
|
|
const struct iovec *iov;
|
|
char __user *buf;
|
|
void *kaddr, *to;
|
|
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
wanted = bytes;
|
|
iov = i->iov;
|
|
skip = i->iov_offset;
|
|
buf = iov->iov_base + skip;
|
|
copy = min(bytes, iov->iov_len - skip);
|
|
|
|
if (!fault_in_pages_readable(buf, copy)) {
|
|
kaddr = kmap_atomic(page);
|
|
to = kaddr + offset;
|
|
|
|
/* first chunk, usually the only one */
|
|
left = __copy_from_user_inatomic(to, buf, copy);
|
|
copy -= left;
|
|
skip += copy;
|
|
to += copy;
|
|
bytes -= copy;
|
|
|
|
while (unlikely(!left && bytes)) {
|
|
iov++;
|
|
buf = iov->iov_base;
|
|
copy = min(bytes, iov->iov_len);
|
|
left = __copy_from_user_inatomic(to, buf, copy);
|
|
copy -= left;
|
|
skip = copy;
|
|
to += copy;
|
|
bytes -= copy;
|
|
}
|
|
if (likely(!bytes)) {
|
|
kunmap_atomic(kaddr);
|
|
goto done;
|
|
}
|
|
offset = to - kaddr;
|
|
buf += copy;
|
|
kunmap_atomic(kaddr);
|
|
copy = min(bytes, iov->iov_len - skip);
|
|
}
|
|
/* Too bad - revert to non-atomic kmap */
|
|
kaddr = kmap(page);
|
|
to = kaddr + offset;
|
|
left = __copy_from_user(to, buf, copy);
|
|
copy -= left;
|
|
skip += copy;
|
|
to += copy;
|
|
bytes -= copy;
|
|
while (unlikely(!left && bytes)) {
|
|
iov++;
|
|
buf = iov->iov_base;
|
|
copy = min(bytes, iov->iov_len);
|
|
left = __copy_from_user(to, buf, copy);
|
|
copy -= left;
|
|
skip = copy;
|
|
to += copy;
|
|
bytes -= copy;
|
|
}
|
|
kunmap(page);
|
|
done:
|
|
if (skip == iov->iov_len) {
|
|
iov++;
|
|
skip = 0;
|
|
}
|
|
i->count -= wanted - bytes;
|
|
i->nr_segs -= iov - i->iov;
|
|
i->iov = iov;
|
|
i->iov_offset = skip;
|
|
return wanted - bytes;
|
|
}
|
|
|
|
/*
|
|
* Fault in the first iovec of the given iov_iter, to a maximum length
|
|
* of bytes. Returns 0 on success, or non-zero if the memory could not be
|
|
* accessed (ie. because it is an invalid address).
|
|
*
|
|
* writev-intensive code may want this to prefault several iovecs -- that
|
|
* would be possible (callers must not rely on the fact that _only_ the
|
|
* first iovec will be faulted with the current implementation).
|
|
*/
|
|
int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
|
|
{
|
|
if (!(i->type & (ITER_BVEC|ITER_KVEC))) {
|
|
char __user *buf = i->iov->iov_base + i->iov_offset;
|
|
bytes = min(bytes, i->iov->iov_len - i->iov_offset);
|
|
return fault_in_pages_readable(buf, bytes);
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_fault_in_readable);
|
|
|
|
void iov_iter_init(struct iov_iter *i, int direction,
|
|
const struct iovec *iov, unsigned long nr_segs,
|
|
size_t count)
|
|
{
|
|
/* It will get better. Eventually... */
|
|
if (segment_eq(get_fs(), KERNEL_DS)) {
|
|
direction |= ITER_KVEC;
|
|
i->type = direction;
|
|
i->kvec = (struct kvec *)iov;
|
|
} else {
|
|
i->type = direction;
|
|
i->iov = iov;
|
|
}
|
|
i->nr_segs = nr_segs;
|
|
i->iov_offset = 0;
|
|
i->count = count;
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_init);
|
|
|
|
static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len)
|
|
{
|
|
char *from = kmap_atomic(page);
|
|
memcpy(to, from + offset, len);
|
|
kunmap_atomic(from);
|
|
}
|
|
|
|
static void memcpy_to_page(struct page *page, size_t offset, char *from, size_t len)
|
|
{
|
|
char *to = kmap_atomic(page);
|
|
memcpy(to + offset, from, len);
|
|
kunmap_atomic(to);
|
|
}
|
|
|
|
static void memzero_page(struct page *page, size_t offset, size_t len)
|
|
{
|
|
char *addr = kmap_atomic(page);
|
|
memset(addr + offset, 0, len);
|
|
kunmap_atomic(addr);
|
|
}
|
|
|
|
size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
|
|
{
|
|
char *from = addr;
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
iterate_and_advance(i, bytes, v,
|
|
__copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,
|
|
v.iov_len),
|
|
memcpy_to_page(v.bv_page, v.bv_offset,
|
|
(from += v.bv_len) - v.bv_len, v.bv_len),
|
|
memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len)
|
|
)
|
|
|
|
return bytes;
|
|
}
|
|
EXPORT_SYMBOL(copy_to_iter);
|
|
|
|
size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
|
|
{
|
|
char *to = addr;
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
iterate_and_advance(i, bytes, v,
|
|
__copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base,
|
|
v.iov_len),
|
|
memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
|
|
v.bv_offset, v.bv_len),
|
|
memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
|
|
)
|
|
|
|
return bytes;
|
|
}
|
|
EXPORT_SYMBOL(copy_from_iter);
|
|
|
|
size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
|
|
{
|
|
char *to = addr;
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
iterate_and_advance(i, bytes, v,
|
|
__copy_from_user_nocache((to += v.iov_len) - v.iov_len,
|
|
v.iov_base, v.iov_len),
|
|
memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
|
|
v.bv_offset, v.bv_len),
|
|
memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
|
|
)
|
|
|
|
return bytes;
|
|
}
|
|
EXPORT_SYMBOL(copy_from_iter_nocache);
|
|
|
|
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
|
|
struct iov_iter *i)
|
|
{
|
|
if (i->type & (ITER_BVEC|ITER_KVEC)) {
|
|
void *kaddr = kmap_atomic(page);
|
|
size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
|
|
kunmap_atomic(kaddr);
|
|
return wanted;
|
|
} else
|
|
return copy_page_to_iter_iovec(page, offset, bytes, i);
|
|
}
|
|
EXPORT_SYMBOL(copy_page_to_iter);
|
|
|
|
size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
|
|
struct iov_iter *i)
|
|
{
|
|
if (i->type & (ITER_BVEC|ITER_KVEC)) {
|
|
void *kaddr = kmap_atomic(page);
|
|
size_t wanted = copy_from_iter(kaddr + offset, bytes, i);
|
|
kunmap_atomic(kaddr);
|
|
return wanted;
|
|
} else
|
|
return copy_page_from_iter_iovec(page, offset, bytes, i);
|
|
}
|
|
EXPORT_SYMBOL(copy_page_from_iter);
|
|
|
|
size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
|
|
{
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
iterate_and_advance(i, bytes, v,
|
|
__clear_user(v.iov_base, v.iov_len),
|
|
memzero_page(v.bv_page, v.bv_offset, v.bv_len),
|
|
memset(v.iov_base, 0, v.iov_len)
|
|
)
|
|
|
|
return bytes;
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_zero);
|
|
|
|
size_t iov_iter_copy_from_user_atomic(struct page *page,
|
|
struct iov_iter *i, unsigned long offset, size_t bytes)
|
|
{
|
|
char *kaddr = kmap_atomic(page), *p = kaddr + offset;
|
|
iterate_all_kinds(i, bytes, v,
|
|
__copy_from_user_inatomic((p += v.iov_len) - v.iov_len,
|
|
v.iov_base, v.iov_len),
|
|
memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
|
|
v.bv_offset, v.bv_len),
|
|
memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
|
|
)
|
|
kunmap_atomic(kaddr);
|
|
return bytes;
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
|
|
|
|
void iov_iter_advance(struct iov_iter *i, size_t size)
|
|
{
|
|
iterate_and_advance(i, size, v, 0, 0, 0)
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_advance);
|
|
|
|
/*
|
|
* Return the count of just the current iov_iter segment.
|
|
*/
|
|
size_t iov_iter_single_seg_count(const struct iov_iter *i)
|
|
{
|
|
if (i->nr_segs == 1)
|
|
return i->count;
|
|
else if (i->type & ITER_BVEC)
|
|
return min(i->count, i->bvec->bv_len - i->iov_offset);
|
|
else
|
|
return min(i->count, i->iov->iov_len - i->iov_offset);
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_single_seg_count);
|
|
|
|
void iov_iter_kvec(struct iov_iter *i, int direction,
|
|
const struct kvec *iov, unsigned long nr_segs,
|
|
size_t count)
|
|
{
|
|
BUG_ON(!(direction & ITER_KVEC));
|
|
i->type = direction;
|
|
i->kvec = (struct kvec *)iov;
|
|
i->nr_segs = nr_segs;
|
|
i->iov_offset = 0;
|
|
i->count = count;
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_kvec);
|
|
|
|
unsigned long iov_iter_alignment(const struct iov_iter *i)
|
|
{
|
|
unsigned long res = 0;
|
|
size_t size = i->count;
|
|
|
|
if (!size)
|
|
return 0;
|
|
|
|
iterate_all_kinds(i, size, v,
|
|
(res |= (unsigned long)v.iov_base | v.iov_len, 0),
|
|
res |= v.bv_offset | v.bv_len,
|
|
res |= (unsigned long)v.iov_base | v.iov_len
|
|
)
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_alignment);
|
|
|
|
ssize_t iov_iter_get_pages(struct iov_iter *i,
|
|
struct page **pages, size_t maxsize, unsigned maxpages,
|
|
size_t *start)
|
|
{
|
|
if (maxsize > i->count)
|
|
maxsize = i->count;
|
|
|
|
if (!maxsize)
|
|
return 0;
|
|
|
|
iterate_all_kinds(i, maxsize, v, ({
|
|
unsigned long addr = (unsigned long)v.iov_base;
|
|
size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
|
|
int n;
|
|
int res;
|
|
|
|
if (len > maxpages * PAGE_SIZE)
|
|
len = maxpages * PAGE_SIZE;
|
|
addr &= ~(PAGE_SIZE - 1);
|
|
n = DIV_ROUND_UP(len, PAGE_SIZE);
|
|
res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages);
|
|
if (unlikely(res < 0))
|
|
return res;
|
|
return (res == n ? len : res * PAGE_SIZE) - *start;
|
|
0;}),({
|
|
/* can't be more than PAGE_SIZE */
|
|
*start = v.bv_offset;
|
|
get_page(*pages = v.bv_page);
|
|
return v.bv_len;
|
|
}),({
|
|
return -EFAULT;
|
|
})
|
|
)
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_get_pages);
|
|
|
|
static struct page **get_pages_array(size_t n)
|
|
{
|
|
struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL);
|
|
if (!p)
|
|
p = vmalloc(n * sizeof(struct page *));
|
|
return p;
|
|
}
|
|
|
|
ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
|
|
struct page ***pages, size_t maxsize,
|
|
size_t *start)
|
|
{
|
|
struct page **p;
|
|
|
|
if (maxsize > i->count)
|
|
maxsize = i->count;
|
|
|
|
if (!maxsize)
|
|
return 0;
|
|
|
|
iterate_all_kinds(i, maxsize, v, ({
|
|
unsigned long addr = (unsigned long)v.iov_base;
|
|
size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
|
|
int n;
|
|
int res;
|
|
|
|
addr &= ~(PAGE_SIZE - 1);
|
|
n = DIV_ROUND_UP(len, PAGE_SIZE);
|
|
p = get_pages_array(n);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
|
|
if (unlikely(res < 0)) {
|
|
kvfree(p);
|
|
return res;
|
|
}
|
|
*pages = p;
|
|
return (res == n ? len : res * PAGE_SIZE) - *start;
|
|
0;}),({
|
|
/* can't be more than PAGE_SIZE */
|
|
*start = v.bv_offset;
|
|
*pages = p = get_pages_array(1);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
get_page(*p = v.bv_page);
|
|
return v.bv_len;
|
|
}),({
|
|
return -EFAULT;
|
|
})
|
|
)
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_get_pages_alloc);
|
|
|
|
size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
|
|
struct iov_iter *i)
|
|
{
|
|
char *to = addr;
|
|
__wsum sum, next;
|
|
size_t off = 0;
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
sum = *csum;
|
|
iterate_and_advance(i, bytes, v, ({
|
|
int err = 0;
|
|
next = csum_and_copy_from_user(v.iov_base,
|
|
(to += v.iov_len) - v.iov_len,
|
|
v.iov_len, 0, &err);
|
|
if (!err) {
|
|
sum = csum_block_add(sum, next, off);
|
|
off += v.iov_len;
|
|
}
|
|
err ? v.iov_len : 0;
|
|
}), ({
|
|
char *p = kmap_atomic(v.bv_page);
|
|
next = csum_partial_copy_nocheck(p + v.bv_offset,
|
|
(to += v.bv_len) - v.bv_len,
|
|
v.bv_len, 0);
|
|
kunmap_atomic(p);
|
|
sum = csum_block_add(sum, next, off);
|
|
off += v.bv_len;
|
|
}),({
|
|
next = csum_partial_copy_nocheck(v.iov_base,
|
|
(to += v.iov_len) - v.iov_len,
|
|
v.iov_len, 0);
|
|
sum = csum_block_add(sum, next, off);
|
|
off += v.iov_len;
|
|
})
|
|
)
|
|
*csum = sum;
|
|
return bytes;
|
|
}
|
|
EXPORT_SYMBOL(csum_and_copy_from_iter);
|
|
|
|
size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum,
|
|
struct iov_iter *i)
|
|
{
|
|
char *from = addr;
|
|
__wsum sum, next;
|
|
size_t off = 0;
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
sum = *csum;
|
|
iterate_and_advance(i, bytes, v, ({
|
|
int err = 0;
|
|
next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len,
|
|
v.iov_base,
|
|
v.iov_len, 0, &err);
|
|
if (!err) {
|
|
sum = csum_block_add(sum, next, off);
|
|
off += v.iov_len;
|
|
}
|
|
err ? v.iov_len : 0;
|
|
}), ({
|
|
char *p = kmap_atomic(v.bv_page);
|
|
next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len,
|
|
p + v.bv_offset,
|
|
v.bv_len, 0);
|
|
kunmap_atomic(p);
|
|
sum = csum_block_add(sum, next, off);
|
|
off += v.bv_len;
|
|
}),({
|
|
next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len,
|
|
v.iov_base,
|
|
v.iov_len, 0);
|
|
sum = csum_block_add(sum, next, off);
|
|
off += v.iov_len;
|
|
})
|
|
)
|
|
*csum = sum;
|
|
return bytes;
|
|
}
|
|
EXPORT_SYMBOL(csum_and_copy_to_iter);
|
|
|
|
int iov_iter_npages(const struct iov_iter *i, int maxpages)
|
|
{
|
|
size_t size = i->count;
|
|
int npages = 0;
|
|
|
|
if (!size)
|
|
return 0;
|
|
|
|
iterate_all_kinds(i, size, v, ({
|
|
unsigned long p = (unsigned long)v.iov_base;
|
|
npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
|
|
- p / PAGE_SIZE;
|
|
if (npages >= maxpages)
|
|
return maxpages;
|
|
0;}),({
|
|
npages++;
|
|
if (npages >= maxpages)
|
|
return maxpages;
|
|
}),({
|
|
unsigned long p = (unsigned long)v.iov_base;
|
|
npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
|
|
- p / PAGE_SIZE;
|
|
if (npages >= maxpages)
|
|
return maxpages;
|
|
})
|
|
)
|
|
return npages;
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_npages);
|