From: Pavel Roskin <proski@gnu.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Howells <dhowells@redhat.com>,
Al Viro <viro@zeniv.linux.org.uk>,
linux-sparse@vger.kernel.org,
Josh Triplett <josh@freedesktop.org>
Subject: Re: [PATCH 2/2] Simplify (and warn about) right shifts that result in zero
Date: Thu, 24 Apr 2008 19:52:11 -0400 [thread overview]
Message-ID: <1209081131.12561.45.camel@dv> (raw)
In-Reply-To: <alpine.LFD.1.10.0804241452250.2779@woody.linux-foundation.org>
On Thu, 2008-04-24 at 14:54 -0700, Linus Torvalds wrote:
> + warning(insn->pos, "right shift by bigger than source value");
The sparse warning for shifts exceeding the target width is:
"shift too big (%d) for type %d"
And the gcc 4.3 warning is
"right shift count >= width of type"
So I would suggest a similar warning is this case. Maybe "right shift
too big (%u) for source type %s" (if the source type is readily
available) or "right shift count (%d) >= width of type (%d)"
By the way, your patch has caught something interesting in
net/mac80211/tkip.c:
iv32 = data[hdr_len + 4] +
(data[hdr_len + 5] >> 8) +
(data[hdr_len + 6] >> 16) +
(data[hdr_len + 7] >> 24);
Wow!
--
Regards,
Pavel Roskin
next prev parent reply other threads:[~2008-04-24 23:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20080424193856.14737.16718.stgit@warthog.procyon.org.uk>
[not found] ` <alpine.LFD.1.10.0804241248290.2779@woody.linux-foundation.org>
2008-04-24 21:52 ` [PATCH 1/2] Fix cast instruction generation Linus Torvalds
2008-04-24 21:54 ` [PATCH 2/2] Simplify (and warn about) right shifts that result in zero Linus Torvalds
2008-04-24 23:52 ` Pavel Roskin [this message]
2008-04-25 0:03 ` Linus Torvalds
2008-04-25 0:34 ` Pavel Roskin
2008-04-25 2:32 ` Josh Triplett
2008-04-25 2:29 ` Josh Triplett
2008-04-25 2:24 ` [PATCH 1/2] Fix cast instruction generation Josh Triplett
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