All of lore.kernel.org
 help / color / mirror / Atom feed
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Pavel Skripkin <paskripkin@gmail.com>,
	rostedt@goodmis.org, tglx@linutronix.de
Cc: linux-kernel@vger.kernel.org,
	syzbot+e68c89a9510c159d9684@syzkaller.appspotmail.com
Subject: Re: [PATCH] profiling: fix shift-out-of-bounds in profile_setup
Date: Fri, 13 Aug 2021 22:27:21 +0900	[thread overview]
Message-ID: <99b9e091-9e95-5e45-5914-38a938840aa6@i-love.sakura.ne.jp> (raw)
In-Reply-To: <a222a2b1-63bd-9fe1-cbc4-ca0e1e214a46@gmail.com>

On 2021/08/13 19:56, Pavel Skripkin wrote:
> I don't get it, sorry. Do you mean, that
> 
> #define MAX_PROF_SHIFT        BITS_PER_LONG
> 
> is better solution here?

Yes, but I feel we don't need to define MAX_PROF_SHIFT because
the type of the integer value which is subjected to shift operation
will be always "unsigned long" and will unlikely change in the future.

>                          And as I understand we can change prof_shift type from "unsigned long" to "unsigned short", rigth?

Yes, "unsigned int" or "unsigned short int", or even "u8" (I don't know
whether compilers generate bad code if "u8" is used). At least, since
get_option() stores result into "int", receiving via "unsigned int" will
be enough.

  reply	other threads:[~2021-08-13 13:28 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-16 19:04 [PATCH] profiling: fix shift-out-of-bounds in profile_setup Pavel Skripkin
2021-08-08 11:21 ` Tetsuo Handa
2021-08-13 10:56   ` Pavel Skripkin
2021-08-13 13:27     ` Tetsuo Handa [this message]
2021-08-13 14:00       ` [PATCH v2] profiling: fix shift-out-of-bounds bugs Pavel Skripkin
2021-08-19 20:46         ` Steven Rostedt
2021-08-29  1:57           ` Tetsuo Handa

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=99b9e091-9e95-5e45-5914-38a938840aa6@i-love.sakura.ne.jp \
    --to=penguin-kernel@i-love.sakura.ne.jp \
    --cc=linux-kernel@vger.kernel.org \
    --cc=paskripkin@gmail.com \
    --cc=rostedt@goodmis.org \
    --cc=syzbot+e68c89a9510c159d9684@syzkaller.appspotmail.com \
    --cc=tglx@linutronix.de \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.