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untangling process_vm_..., part 4

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instead of passing vector size (by value) and index (by reference),
pass the number of elements remaining.  That's all we care about
in these functions by that point.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2014-02-05 10:40:15 -05:00
parent 12e3004e46
commit 1291afc181
1 changed files with 13 additions and 16 deletions
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29
mm/process_vm_access.c
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@ -46,8 +46,7 @@ static int process_vm_rw_pages(struct task_struct *task,
unsigned long start_offset, unsigned long start_offset,
unsigned long len, unsigned long len,
const struct iovec **iovp, const struct iovec **iovp,
unsigned long lvec_cnt, unsigned long *left,
unsigned long *lvec_current,
size_t *lvec_offset, size_t *lvec_offset,
int vm_write, int vm_write,
unsigned int nr_pages_to_copy, unsigned int nr_pages_to_copy,
@ -78,15 +77,14 @@ static int process_vm_rw_pages(struct task_struct *task,
/* Do the copy for each page */ /* Do the copy for each page */
for (pgs_copied = 0; for (pgs_copied = 0;
(pgs_copied < nr_pages_to_copy) && (*lvec_current < lvec_cnt); (pgs_copied < nr_pages_to_copy) && *left;
pgs_copied++) { pgs_copied++) {
/* Make sure we have a non zero length iovec */ /* Make sure we have a non zero length iovec */
while (*lvec_current < lvec_cnt while (*left && iov->iov_len == 0) {
&& iov->iov_len == 0) {
iov++; iov++;
(*lvec_current)++; (*left)--;
} }
if (*lvec_current == lvec_cnt) if (!*left)
break; break;
/* /*
@ -125,7 +123,7 @@ static int process_vm_rw_pages(struct task_struct *task,
* Need to copy remaining part of page into the * Need to copy remaining part of page into the
* next iovec if there are any bytes left in page * next iovec if there are any bytes left in page
*/ */
(*lvec_current)++; (*left)--;
iov++; iov++;
*lvec_offset = 0; *lvec_offset = 0;
start_offset = (start_offset + bytes_to_copy) start_offset = (start_offset + bytes_to_copy)
@ -175,8 +173,7 @@ end:
static int process_vm_rw_single_vec(unsigned long addr, static int process_vm_rw_single_vec(unsigned long addr,
unsigned long len, unsigned long len,
const struct iovec **iovp, const struct iovec **iovp,
unsigned long lvec_cnt, unsigned long *left,
unsigned long *lvec_current,
size_t *lvec_offset, size_t *lvec_offset,
struct page **process_pages, struct page **process_pages,
struct mm_struct *mm, struct mm_struct *mm,
@ -201,14 +198,14 @@ static int process_vm_rw_single_vec(unsigned long addr,
return 0; return 0;
nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1; nr_pages = (addr + len - 1) / PAGE_SIZE - addr / PAGE_SIZE + 1;
while ((nr_pages_copied < nr_pages) && (*lvec_current < lvec_cnt)) { while ((nr_pages_copied < nr_pages) && *left) {
nr_pages_to_copy = min(nr_pages - nr_pages_copied, nr_pages_to_copy = min(nr_pages - nr_pages_copied,
max_pages_per_loop); max_pages_per_loop);
rc = process_vm_rw_pages(task, mm, process_pages, pa, rc = process_vm_rw_pages(task, mm, process_pages, pa,
start_offset, len, start_offset, len,
iovp, lvec_cnt, iovp, left,
lvec_current, lvec_offset, lvec_offset,
vm_write, nr_pages_to_copy, vm_write, nr_pages_to_copy,
&bytes_copied_loop); &bytes_copied_loop);
start_offset = 0; start_offset = 0;
@ -259,7 +256,7 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
ssize_t bytes_copied = 0; ssize_t bytes_copied = 0;
unsigned long nr_pages = 0; unsigned long nr_pages = 0;
unsigned long nr_pages_iov; unsigned long nr_pages_iov;
unsigned long iov_l_curr_idx = 0; unsigned long left = liovcnt;
size_t iov_l_curr_offset = 0; size_t iov_l_curr_offset = 0;
ssize_t iov_len; ssize_t iov_len;
@ -315,10 +312,10 @@ static ssize_t process_vm_rw_core(pid_t pid, const struct iovec *lvec,
goto put_task_struct; goto put_task_struct;
} }
for (i = 0; i < riovcnt && iov_l_curr_idx < liovcnt; i++) { for (i = 0; i < riovcnt && left; i++) {
rc = process_vm_rw_single_vec( rc = process_vm_rw_single_vec(
(unsigned long)rvec[i].iov_base, rvec[i].iov_len, (unsigned long)rvec[i].iov_base, rvec[i].iov_len,
&lvec, liovcnt, &iov_l_curr_idx, &iov_l_curr_offset, &lvec, &left, &iov_l_curr_offset,
process_pages, mm, task, vm_write, &bytes_copied_loop); process_pages, mm, task, vm_write, &bytes_copied_loop);
bytes_copied += bytes_copied_loop; bytes_copied += bytes_copied_loop;
if (rc != 0) { if (rc != 0) {