From: Alexey Dobriyan <adobriyan@gmail.com>
To: akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH 2/5] proc: more "unsigned int" in /proc/*/cmdline
Date: Wed, 21 Feb 2018 22:26:05 +0300 [thread overview]
Message-ID: <20180221192605.GB28548@avx2> (raw)
In-Reply-To: <20180221192339.GA28548@avx2>
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.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
fs/proc/base.c | 29 ++++++++++++-----------------
1 file changed, 12 insertions(+), 17 deletions(-)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -280,9 +280,10 @@ 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, 0);
- if (rv <= 0)
+ if (access_remote_vm(mm, arg_end - 1, &c, 1, 0) != 1) {
+ rv = 0;
goto out_free_page;
+ }
rv = 0;
@@ -294,14 +295,11 @@ 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;
-
- _count = min3(count, len, PAGE_SIZE);
- nr_read = access_remote_vm(mm, p, page, _count, 0);
- if (nr_read < 0)
- rv = nr_read;
- if (nr_read <= 0)
+ unsigned int nr_read;
+
+ nr_read = min3(count, len, PAGE_SIZE);
+ nr_read = access_remote_vm(mm, p, page, nr_read, 0);
+ if (nr_read == 0)
goto out_free_page;
if (copy_to_user(buf, page, nr_read)) {
@@ -339,15 +337,12 @@ 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, 0);
- 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, 0);
+ if (nr_read == 0)
goto out_free_page;
/*
next prev parent reply other threads:[~2018-02-21 19:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-21 19:23 [PATCH 1/5] proc: make /proc/*/cmdline go through LSM Alexey Dobriyan
2018-02-21 19:26 ` Alexey Dobriyan [this message]
2018-02-21 19:27 ` [PATCH 3/5] proc: somewhat simpler code for /proc/*/cmdline Alexey Dobriyan
2018-02-21 19:30 ` [PATCH 4/5] proc: simpler iterations " Alexey Dobriyan
2018-02-21 19:33 ` [PATCH 5/5] proc: deduplicate /proc/*/cmdline implementation Alexey Dobriyan
2018-04-20 0:15 ` [PATCH 4/5] proc: simpler iterations for /proc/*/cmdline Andrew Morton
2018-04-20 19:46 ` Alexey Dobriyan
2018-02-21 19:28 ` [PATCH 1/5] proc: make /proc/*/cmdline go through LSM Andy Shevchenko
2018-02-21 19:39 ` Alexey Dobriyan
2018-02-21 20:06 ` Andrew Morton
2018-02-23 19:43 ` [PATCH v2 " Alexey Dobriyan
2018-04-20 0:02 ` [PATCH " Andrew Morton
2018-04-20 19:25 ` Alexey Dobriyan
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