From: Joe Perches <joe@perches.com>
To: Mike Frysinger <vapier@gentoo.org>
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 1/2 v2] binfmt_misc: add comments & debug logs
Date: Mon, 20 Oct 2014 15:59:56 -0700 [thread overview]
Message-ID: <1413845996.5407.2.camel@perches.com> (raw)
In-Reply-To: <1413845160-22497-1-git-send-email-vapier@gentoo.org>
On Mon, 2014-10-20 at 18:45 -0400, Mike Frysinger wrote:
> let's deploy extensive pr_debug markers at
> logical parse points, and add comments to the dense parsing logic. It
> let's you see exactly where the parsing aborts, the string the kernel
> received (useful when dealing with shell code), how it translated the
> buffers to binary data, and how it will apply the mask at runtime.
Mostly trivia:
> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
[]
> @@ -323,46 +343,113 @@ static Node *create_entry(const char __user *buffer, size_t count)
[]
> + if (e->mask) {
> + int i;
> + char *masked = kmalloc(e->size, GFP_USER);
Why GFP_USER? Does it need it?
> + print_hex_dump_bytes(
> + KBUILD_MODNAME ": register: mask[decoded]: ",
> + DUMP_PREFIX_NONE, e->mask, e->size);
> +
> + if (masked) {
> + for (i = 0; i < e->size; ++i)
> + masked[i] = e->magic[i] & e->mask[i];
> + print_hex_dump_bytes(
> + KBUILD_MODNAME ": register: magic[masked]: ",
> + DUMP_PREFIX_NONE, masked, e->size);
> +
> + kfree(masked);
[]
> @@ -553,11 +645,17 @@ static ssize_t bm_entry_write(struct file *file, const char __user *buffer,
> int res = parse_command(buffer, count);
>
> switch (res) {
> - case 1: clear_bit(Enabled, &e->flags);
> + case 1:
> + /* Disable this handler. */
> + clear_bit(Enabled, &e->flags);
> break;
> - case 2: set_bit(Enabled, &e->flags);
> + case 2:
> + /* Enable this handler. */
> + set_bit(Enabled, &e->flags);
> break;
> - case 3: root = dget(file->f_path.dentry->d_sb->s_root);
> + case 3:
> + /* Delete this handler. */
> + root = dget(file->f_path.dentry->d_sb->s_root);
> mutex_lock(&root->d_inode->i_mutex);
>
> kill_node(e);
Maybe move the case indents one tab position left
switch (res) {
case 1: /* Disable handler */
clear_bit(Enabled, ...);
break;
case 2: /* Enable handler */
set_bit(...);
break;
case 3: /* Delete handler */
etc...
}
> @@ -661,9 +759,17 @@ static ssize_t bm_status_write(struct file * file, const char __user * buffer,
> struct dentry *root;
>
> switch (res) {
> - case 1: enabled = 0; break;
> - case 2: enabled = 1; break;
> - case 3: root = dget(file->f_path.dentry->d_sb->s_root);
> + case 1:
> + /* Disable all handlers. */
> + enabled = 0;
> + break;
> + case 2:
> + /* Enable all handlers. */
> + enabled = 1;
> + break;
> + case 3:
> + /* Delete all handlers. */
> + root = dget(file->f_path.dentry->d_sb->s_root);
> mutex_lock(&root->d_inode->i_mutex);
>
> while (!list_empty(&entries))
here too.
next prev parent reply other threads:[~2014-10-20 23:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-19 23:03 [PATCH 1/2] binfmt_misc: add comments & debug logs Mike Frysinger
2014-10-19 23:03 ` [PATCH 2/2] binfmt_misc: clean up code style a bit Mike Frysinger
2014-10-20 0:41 ` [PATCH 1/2] binfmt_misc: add comments & debug logs Joe Perches
2014-10-20 22:37 ` Mike Frysinger
2014-10-20 22:45 ` [PATCH 1/2 v2] " Mike Frysinger
2014-10-20 22:46 ` [PATCH 2/2 v2] binfmt_misc: clean up code style a bit Mike Frysinger
2014-10-20 22:59 ` Joe Perches [this message]
2014-10-20 23:54 ` [PATCH 1/2 v2] binfmt_misc: add comments & debug logs Mike Frysinger
2014-10-28 22:58 ` Andrew Morton
2014-10-28 23:25 ` Mike Frysinger
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1413845996.5407.2.camel@perches.com \
--to=joe@perches.com \
--cc=akpm@linux-foundation.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=vapier@gentoo.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).