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iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper

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Incidentally, ITER_XARRAY did *not* free the sucker in case when
iter_xarray_populate_pages() returned 0...

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2022-06-10 20:38:20 -04:00
parent 12d426ab64
commit 91329559eb
1 changed files with 22 additions and 16 deletions
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38
lib/iov_iter.c
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@ -1506,15 +1506,10 @@ static ssize_t pipe_get_pages_alloc(struct iov_iter *i,
maxsize = n;
else
npages = DIV_ROUND_UP(maxsize + off, PAGE_SIZE);
p = get_pages_array(npages);
*pages = p = get_pages_array(npages);
if (!p)
return -ENOMEM;
n = __pipe_get_pages(i, maxsize, p, off);
if (n > 0)
*pages = p;
else
kvfree(p);
return n;
return __pipe_get_pages(i, maxsize, p, off);
}
static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i,
@ -1544,10 +1539,9 @@ static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i,
count++;
}
p = get_pages_array(count);
*pages = p = get_pages_array(count);
if (!p)
return -ENOMEM;
*pages = p;
nr = iter_xarray_populate_pages(p, i->xarray, index, count);
if (nr == 0)
@ -1556,7 +1550,7 @@ static ssize_t iter_xarray_get_pages_alloc(struct iov_iter *i,
return min_t(size_t, nr * PAGE_SIZE - offset, maxsize);
}
ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,
struct page ***pages, size_t maxsize,
size_t *start)
{
@ -1583,16 +1577,12 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
*start = addr % PAGE_SIZE;
addr &= PAGE_MASK;
n = DIV_ROUND_UP(maxsize + *start, PAGE_SIZE);
p = get_pages_array(n);
*pages = p = get_pages_array(n);
if (!p)
return -ENOMEM;
res = get_user_pages_fast(addr, n, gup_flags, p);
if (unlikely(res <= 0)) {
kvfree(p);
*pages = NULL;
if (unlikely(res <= 0))
return res;
}
*pages = p;
return min_t(size_t, maxsize, res * PAGE_SIZE - *start);
}
if (iov_iter_is_bvec(i)) {
@ -1613,6 +1603,22 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
return iter_xarray_get_pages_alloc(i, pages, maxsize, start);
return -EFAULT;
}
ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
struct page ***pages, size_t maxsize,
size_t *start)
{
ssize_t len;
*pages = NULL;
len = __iov_iter_get_pages_alloc(i, pages, maxsize, start);
if (len <= 0) {
kvfree(*pages);
*pages = NULL;
}
return len;
}
EXPORT_SYMBOL(iov_iter_get_pages_alloc);
size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,