forked from Minki/linux
process_vm_access: switch to iov_iter
instead of keeping its pieces in separate variables and passing pointers to all of them... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
parent
1291afc181
commit
9f78bdfabf
@ -45,9 +45,7 @@ static int process_vm_rw_pages(struct task_struct *task,
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unsigned long pa,
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unsigned long start_offset,
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unsigned long len,
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const struct iovec **iovp,
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unsigned long *left,
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size_t *lvec_offset,
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struct iov_iter *iter,
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int vm_write,
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unsigned int nr_pages_to_copy,
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ssize_t *bytes_copied)
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@ -59,7 +57,7 @@ static int process_vm_rw_pages(struct task_struct *task,
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int ret;
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ssize_t bytes_to_copy;
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ssize_t rc = 0;
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const struct iovec *iov = *iovp;
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const struct iovec *iov = iter->iov;
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*bytes_copied = 0;
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@ -77,14 +75,14 @@ static int process_vm_rw_pages(struct task_struct *task,
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/* Do the copy for each page */
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for (pgs_copied = 0;
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(pgs_copied < nr_pages_to_copy) && *left;
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(pgs_copied < nr_pages_to_copy) && iter->nr_segs;
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pgs_copied++) {
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/* Make sure we have a non zero length iovec */
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while (*left && iov->iov_len == 0) {
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while (iter->nr_segs && iov->iov_len == 0) {
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iov++;
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(*left)--;
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iter->nr_segs--;
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}
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if (!*left)
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if (!iter->nr_segs)
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break;
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/*
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@ -96,18 +94,18 @@ static int process_vm_rw_pages(struct task_struct *task,
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len - *bytes_copied);
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bytes_to_copy = min_t(ssize_t, bytes_to_copy,
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iov->iov_len
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- *lvec_offset);
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- iter->iov_offset);
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target_kaddr = kmap(process_pages[pgs_copied]) + start_offset;
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if (vm_write)
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ret = copy_from_user(target_kaddr,
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iov->iov_base
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+ *lvec_offset,
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+ iter->iov_offset,
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bytes_to_copy);
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else
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ret = copy_to_user(iov->iov_base
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+ *lvec_offset,
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+ iter->iov_offset,
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target_kaddr, bytes_to_copy);
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kunmap(process_pages[pgs_copied]);
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if (ret) {
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@ -117,15 +115,15 @@ static int process_vm_rw_pages(struct task_struct *task,
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goto end;
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}
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*bytes_copied += bytes_to_copy;
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*lvec_offset += bytes_to_copy;
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if (*lvec_offset == iov->iov_len) {
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iter->iov_offset += bytes_to_copy;
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if (iter->iov_offset == iov->iov_len) {
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/*
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* Need to copy remaining part of page into the
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* next iovec if there are any bytes left in page
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*/
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(*left)--;
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iter->nr_segs--;
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iov++;
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*lvec_offset = 0;
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iter->iov_offset = 0;
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start_offset = (start_offset + bytes_to_copy)
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% PAGE_SIZE;
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if (start_offset)
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@ -147,7 +145,7 @@ end:
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put_page(process_pages[j]);
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}
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*iovp = iov;
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iter->iov = iov;
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return rc;
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}
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@ -172,9 +170,7 @@ end:
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*/
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static int process_vm_rw_single_vec(unsigned long addr,
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unsigned long len,
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const struct iovec **iovp,
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unsigned long *left,
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size_t *lvec_offset,
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struct iov_iter *iter,
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struct page **process_pages,
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struct mm_struct *mm,
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struct task_struct *task,
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@ -198,14 +194,12 @@ static int process_vm_rw_single_vec(unsigned long addr,
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return 0;
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nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1;
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while ((nr_pages_copied < nr_pages) && *left) {
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while ((nr_pages_copied < nr_pages) && iter->nr_segs) {
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nr_pages_to_copy = min(nr_pages - nr_pages_copied,
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max_pages_per_loop);
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rc = process_vm_rw_pages(task, mm, process_pages, pa,
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start_offset, len,
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iovp, left,
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lvec_offset,
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start_offset, len, iter,
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vm_write, nr_pages_to_copy,
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&bytes_copied_loop);
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start_offset = 0;
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@ -240,8 +234,7 @@ static int process_vm_rw_single_vec(unsigned long addr,
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* return less bytes than expected if an error occurs during the copying
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* process.
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*/
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static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
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unsigned long liovcnt,
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static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter,
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const struct iovec *rvec,
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unsigned long riovcnt,
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unsigned long flags, int vm_write)
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@ -256,8 +249,6 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
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ssize_t bytes_copied = 0;
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unsigned long nr_pages = 0;
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unsigned long nr_pages_iov;
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unsigned long left = liovcnt;
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size_t iov_l_curr_offset = 0;
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ssize_t iov_len;
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/*
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@ -312,11 +303,11 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
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goto put_task_struct;
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}
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for (i = 0; i < riovcnt && left; i++) {
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for (i = 0; i < riovcnt && iter->nr_segs; i++) {
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rc = process_vm_rw_single_vec(
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(unsigned long)rvec[i].iov_base, rvec[i].iov_len,
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&lvec, &left, &iov_l_curr_offset,
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process_pages, mm, task, vm_write, &bytes_copied_loop);
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iter, process_pages, mm, task, vm_write,
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&bytes_copied_loop);
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bytes_copied += bytes_copied_loop;
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if (rc != 0) {
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/* If we have managed to copy any data at all then
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@ -365,6 +356,7 @@ static ssize_t process_vm_rw(pid_t pid,
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struct iovec iovstack_r[UIO_FASTIOV];
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struct iovec *iov_l = iovstack_l;
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struct iovec *iov_r = iovstack_r;
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struct iov_iter iter;
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ssize_t rc;
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if (flags != 0)
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@ -380,13 +372,14 @@ static ssize_t process_vm_rw(pid_t pid,
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if (rc <= 0)
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goto free_iovecs;
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iov_iter_init(&iter, iov_l, liovcnt, rc, 0);
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rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV,
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iovstack_r, &iov_r);
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if (rc <= 0)
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goto free_iovecs;
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rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
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vm_write);
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rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
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free_iovecs:
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if (iov_r != iovstack_r)
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@ -426,6 +419,7 @@ compat_process_vm_rw(compat_pid_t pid,
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struct iovec iovstack_r[UIO_FASTIOV];
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struct iovec *iov_l = iovstack_l;
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struct iovec *iov_r = iovstack_r;
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struct iov_iter iter;
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ssize_t rc = -EFAULT;
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if (flags != 0)
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@ -441,14 +435,14 @@ compat_process_vm_rw(compat_pid_t pid,
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&iov_l);
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if (rc <= 0)
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goto free_iovecs;
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iov_iter_init(&iter, iov_l, liovcnt, rc, 0);
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rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt,
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UIO_FASTIOV, iovstack_r,
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&iov_r);
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if (rc <= 0)
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goto free_iovecs;
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rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
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vm_write);
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rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
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free_iovecs:
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if (iov_r != iovstack_r)
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