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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>
hifive-unleashed-5.1
Al Viro 2014-02-05 11:51:53 -05:00
parent 1291afc181
commit 9f78bdfabf
1 changed files with 28 additions and 34 deletions
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62
mm/process_vm_access.c
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@ -45,9 +45,7 @@ static int process_vm_rw_pages(struct task_struct *task,
unsigned long pa,
unsigned long start_offset,
unsigned long len,
const struct iovec **iovp,
unsigned long *left,
size_t *lvec_offset,
struct iov_iter *iter,
int vm_write,
unsigned int nr_pages_to_copy,
ssize_t *bytes_copied)
@ -59,7 +57,7 @@ static int process_vm_rw_pages(struct task_struct *task,
int ret;
ssize_t bytes_to_copy;
ssize_t rc = 0;
const struct iovec *iov = *iovp;
const struct iovec *iov = iter->iov;
*bytes_copied = 0;
@ -77,14 +75,14 @@ static int process_vm_rw_pages(struct task_struct *task,
/* Do the copy for each page */
for (pgs_copied = 0;
(pgs_copied < nr_pages_to_copy) && *left;
(pgs_copied < nr_pages_to_copy) && iter->nr_segs;
pgs_copied++) {
/* Make sure we have a non zero length iovec */
while (*left && iov->iov_len == 0) {
while (iter->nr_segs && iov->iov_len == 0) {
iov++;
(*left)--;
iter->nr_segs--;
}
if (!*left)
if (!iter->nr_segs)
break;
/*
@ -96,18 +94,18 @@ static int process_vm_rw_pages(struct task_struct *task,
len - *bytes_copied);
bytes_to_copy = min_t(ssize_t, bytes_to_copy,
iov->iov_len
- *lvec_offset);
- iter->iov_offset);
target_kaddr = kmap(process_pages[pgs_copied]) + start_offset;
if (vm_write)
ret = copy_from_user(target_kaddr,
iov->iov_base
+ *lvec_offset,
+ iter->iov_offset,
bytes_to_copy);
else
ret = copy_to_user(iov->iov_base
+ *lvec_offset,
+ iter->iov_offset,
target_kaddr, bytes_to_copy);
kunmap(process_pages[pgs_copied]);
if (ret) {
@ -117,15 +115,15 @@ static int process_vm_rw_pages(struct task_struct *task,
goto end;
}
*bytes_copied += bytes_to_copy;
*lvec_offset += bytes_to_copy;
if (*lvec_offset == iov->iov_len) {
iter->iov_offset += bytes_to_copy;
if (iter->iov_offset == iov->iov_len) {
/*
* Need to copy remaining part of page into the
* next iovec if there are any bytes left in page
*/
(*left)--;
iter->nr_segs--;
iov++;
*lvec_offset = 0;
iter->iov_offset = 0;
start_offset = (start_offset + bytes_to_copy)
% PAGE_SIZE;
if (start_offset)
@ -147,7 +145,7 @@ end:
put_page(process_pages[j]);
}
*iovp = iov;
iter->iov = iov;
return rc;
}
@ -172,9 +170,7 @@ end:
*/
static int process_vm_rw_single_vec(unsigned long addr,
unsigned long len,
const struct iovec **iovp,
unsigned long *left,
size_t *lvec_offset,
struct iov_iter *iter,
struct page **process_pages,
struct mm_struct *mm,
struct task_struct *task,
@ -198,14 +194,12 @@ static int process_vm_rw_single_vec(unsigned long addr,
return 0;
nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1;
while ((nr_pages_copied < nr_pages) && *left) {
while ((nr_pages_copied < nr_pages) && iter->nr_segs) {
nr_pages_to_copy = min(nr_pages - nr_pages_copied,
max_pages_per_loop);
rc = process_vm_rw_pages(task, mm, process_pages, pa,
start_offset, len,
iovp, left,
lvec_offset,
start_offset, len, iter,
vm_write, nr_pages_to_copy,
&bytes_copied_loop);
start_offset = 0;
@ -240,8 +234,7 @@ static int process_vm_rw_single_vec(unsigned long addr,
* return less bytes than expected if an error occurs during the copying
* process.
*/
static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
unsigned long liovcnt,
static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter,
const struct iovec *rvec,
unsigned long riovcnt,
unsigned long flags, int vm_write)
@ -256,8 +249,6 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
ssize_t bytes_copied = 0;
unsigned long nr_pages = 0;
unsigned long nr_pages_iov;
unsigned long left = liovcnt;
size_t iov_l_curr_offset = 0;
ssize_t iov_len;
/*
@ -312,11 +303,11 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
goto put_task_struct;
}
for (i = 0; i < riovcnt && left; i++) {
for (i = 0; i < riovcnt && iter->nr_segs; i++) {
rc = process_vm_rw_single_vec(
(unsigned long)rvec[i].iov_base, rvec[i].iov_len,
&lvec, &left, &iov_l_curr_offset,
process_pages, mm, task, vm_write, &bytes_copied_loop);
iter, process_pages, mm, task, vm_write,
&bytes_copied_loop);
bytes_copied += bytes_copied_loop;
if (rc != 0) {
/* If we have managed to copy any data at all then
@ -365,6 +356,7 @@ static ssize_t process_vm_rw(pid_t pid,
struct iovec iovstack_r[UIO_FASTIOV];
struct iovec *iov_l = iovstack_l;
struct iovec *iov_r = iovstack_r;
struct iov_iter iter;
ssize_t rc;
if (flags != 0)
@ -380,13 +372,14 @@ static ssize_t process_vm_rw(pid_t pid,
if (rc <= 0)
goto free_iovecs;
iov_iter_init(&iter, iov_l, liovcnt, rc, 0);
rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV,
iovstack_r, &iov_r);
if (rc <= 0)
goto free_iovecs;
rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
vm_write);
rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
free_iovecs:
if (iov_r != iovstack_r)
@ -426,6 +419,7 @@ compat_process_vm_rw(compat_pid_t pid,
struct iovec iovstack_r[UIO_FASTIOV];
struct iovec *iov_l = iovstack_l;
struct iovec *iov_r = iovstack_r;
struct iov_iter iter;
ssize_t rc = -EFAULT;
if (flags != 0)
@ -441,14 +435,14 @@ compat_process_vm_rw(compat_pid_t pid,
&iov_l);
if (rc <= 0)
goto free_iovecs;
iov_iter_init(&iter, iov_l, liovcnt, rc, 0);
rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt,
UIO_FASTIOV, iovstack_r,
&iov_r);
if (rc <= 0)
goto free_iovecs;
rc = process_vm_rw_core(pid, iov_l, liovcnt, iov_r, riovcnt, flags,
vm_write);
rc = process_vm_rw_core(pid, &iter, iov_r, riovcnt, flags, vm_write);
free_iovecs:
if (iov_r != iovstack_r)