public inbox for netdev@vger.kernel.org
 help / color / mirror / Atom feed
From: Dan Carpenter <error27@gmail.com>
To: Vladimir Oltean <olteanv@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH net] lib: packing: fix shift wrapping in bit_reverse()
Date: Wed, 7 Dec 2022 14:23:28 +0300	[thread overview]
Message-ID: <Y5B3sAcS6qKSt+lS@kili> (raw)

The bit_reverse() function is clearly supposed to be able to handle
64 bit values, but the types for "(1 << i)" and "bit << (width - i - 1)"
are not enough to handle more than 32 bits.

Fixes: 554aae35007e ("lib: Add support for generic packing operations")
Signed-off-by: Dan Carpenter <error27@gmail.com>
---
 lib/packing.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/lib/packing.c b/lib/packing.c
index 9a72f4bbf0e2..9d7418052f5a 100644
--- a/lib/packing.c
+++ b/lib/packing.c
@@ -32,12 +32,11 @@ static int get_reverse_lsw32_offset(int offset, size_t len)
 static u64 bit_reverse(u64 val, unsigned int width)
 {
 	u64 new_val = 0;
-	unsigned int bit;
 	unsigned int i;
 
 	for (i = 0; i < width; i++) {
-		bit = (val & (1 << i)) != 0;
-		new_val |= (bit << (width - i - 1));
+		if (val & BIT_ULL(1))
+			new_val |= BIT_ULL(width - i - 1);
 	}
 	return new_val;
 }
-- 
2.35.1


             reply	other threads:[~2022-12-07 11:23 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-07 11:23 Dan Carpenter [this message]
2022-12-07 12:19 ` [PATCH net] lib: packing: fix shift wrapping in bit_reverse() Vladimir Oltean
2022-12-07 12:21   ` Dan Carpenter
2022-12-07 12:22     ` Vladimir Oltean
2022-12-07 12:51       ` Dan Carpenter
2022-12-07 13:06         ` Vladimir Oltean
2022-12-07 13:02       ` Vladimir Oltean
2022-12-07 19:41     ` David Laight
2022-12-08 16:58       ` Vladimir Oltean
2022-12-09  8:21 ` Uladzislau Koshchanka
2022-12-09 14:30   ` Vladimir Oltean
2022-12-09 21:01     ` Uladzislau Koshchanka
2022-12-09 22:06       ` Vladimir Oltean
2022-12-09 22:07         ` Vladimir Oltean
2022-12-10  0:44         ` [PATCH] lib: packing: replace bit_reverse() with bitrev8() Uladzislau Koshchanka
2022-12-12 23:04           ` Vladimir Oltean
2022-12-12 23:30           ` patchwork-bot+netdevbpf

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=Y5B3sAcS6qKSt+lS@kili \
    --to=error27@gmail.com \
    --cc=davem@davemloft.net \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=olteanv@gmail.com \
    /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