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proc: more "unsigned int" in /proc/*/cmdline 

access_remote_vm() doesn't return negative errors, it returns number of
bytes read/written (0 if error occurs).  This allows to delete some
comparisons which never trigger.

Reuse "nr_read" variable while I'm at it.

Link: http://lkml.kernel.org/r/20180221192605.GB28548@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexey Dobriyan 2018-06-07 17:09:52 -07:00 committed by Linus Torvalds
parent 72eb7de9c1
commit b42262af5e
1 changed files with 11 additions and 16 deletions
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27
fs/proc/base.c
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@ -261,9 +261,10 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
* Inherently racy -- command line shares address space * Inherently racy -- command line shares address space
* with code and data. * with code and data.
*/ */
rv = access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON); if (access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON) != 1) {
if (rv <= 0) rv = 0;
goto out_free_page; goto out_free_page;
}
rv = 0; rv = 0;
@ -275,14 +276,11 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
p = arg_start + *pos; p = arg_start + *pos;
len = len1 - *pos; len = len1 - *pos;
while (count > 0 && len > 0) { while (count > 0 && len > 0) {
unsigned int _count; unsigned int nr_read;
int nr_read;
_count = min3(count, len, PAGE_SIZE); nr_read = min3(count, len, PAGE_SIZE);
nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON); nr_read = access_remote_vm(mm, p, page, nr_read, FOLL_ANON);
if (nr_read < 0) if (nr_read == 0)
rv = nr_read;
if (nr_read <= 0)
goto out_free_page; goto out_free_page;
if (copy_to_user(buf, page, nr_read)) { if (copy_to_user(buf, page, nr_read)) {
@ -320,15 +318,12 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
p = cmdline[i].p + pos1; p = cmdline[i].p + pos1;
len = cmdline[i].len - pos1; len = cmdline[i].len - pos1;
while (count > 0 && len > 0) { while (count > 0 && len > 0) {
unsigned int _count, l; unsigned int nr_read, l;
int nr_read;
bool final; bool final;
_count = min3(count, len, PAGE_SIZE); nr_read = min3(count, len, PAGE_SIZE);
nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON); nr_read = access_remote_vm(mm, p, page, nr_read, FOLL_ANON);
if (nr_read < 0) if (nr_read == 0)
rv = nr_read;
if (nr_read <= 0)
goto out_free_page; goto out_free_page;
/* /*