Skip to content

Commit

Permalink
proc: somewhat simpler code for /proc/*/cmdline
Browse files Browse the repository at this point in the history
"final" variable is OK but we can get away with less lines.

Link: http://lkml.kernel.org/r/20180221192751.GC28548@avx2
Signed-off-by: Alexey Dobriyan <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
  • Loading branch information
Alexey Dobriyan authored and torvalds committed Jun 8, 2018
1 parent b42262a commit 6a6b9c4
Showing 1 changed file with 9 additions and 15 deletions.
24 changes: 9 additions & 15 deletions fs/proc/base.c
Original file line number Diff line number Diff line change
Expand Up @@ -318,8 +318,7 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
p = cmdline[i].p + pos1;
len = cmdline[i].len - pos1;
while (count > 0 && len > 0) {
unsigned int nr_read, l;
bool final;
unsigned int nr_read, nr_write;

nr_read = min3(count, len, PAGE_SIZE);
nr_read = access_remote_vm(mm, p, page, nr_read, FOLL_ANON);
Expand All @@ -330,25 +329,20 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
* Command line can be shorter than whole ARGV
* even if last "marker" byte says it is not.
*/
final = false;
l = strnlen(page, nr_read);
if (l < nr_read) {
nr_read = l;
final = true;
}
nr_write = strnlen(page, nr_read);

if (copy_to_user(buf, page, nr_read)) {
if (copy_to_user(buf, page, nr_write)) {
rv = -EFAULT;
goto out_free_page;
}

p += nr_read;
len -= nr_read;
buf += nr_read;
count -= nr_read;
rv += nr_read;
p += nr_write;
len -= nr_write;
buf += nr_write;
count -= nr_write;
rv += nr_write;

if (final)
if (nr_write < nr_read)
goto out_free_page;
}

Expand Down

0 comments on commit 6a6b9c4

Please sign in to comment.