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>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index ef3f7df..159abd0 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -261,9 +261,10 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
* Inherently racy -- command line shares address space
* with code and data.
*/
- rv = access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON);
- if (rv <= 0)
+ if (access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON) != 1) {
+ rv = 0;
goto out_free_page;
+ }
rv = 0;
@@ -275,14 +276,11 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
p = arg_start + *pos;
len = len1 - *pos;
while (count > 0 && len > 0) {
- unsigned int _count;
- int nr_read;
+ unsigned int nr_read;
- _count = min3(count, len, PAGE_SIZE);
- nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON);
- if (nr_read < 0)
- rv = nr_read;
- if (nr_read <= 0)
+ nr_read = min3(count, len, PAGE_SIZE);
+ nr_read = access_remote_vm(mm, p, page, nr_read, FOLL_ANON);
+ if (nr_read == 0)
goto out_free_page;
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;
len = cmdline[i].len - pos1;
while (count > 0 && len > 0) {
- unsigned int _count, l;
- int nr_read;
+ unsigned int nr_read, l;
bool final;
- _count = min3(count, len, PAGE_SIZE);
- nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON);
- if (nr_read < 0)
- rv = nr_read;
- if (nr_read <= 0)
+ nr_read = min3(count, len, PAGE_SIZE);
+ nr_read = access_remote_vm(mm, p, page, nr_read, FOLL_ANON);
+ if (nr_read == 0)
goto out_free_page;
/*
