From: Dibyendu Majumdar <mobile@majumdar.org.uk>
To: Christopher Li <sparse@chrisli.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux-Sparse <linux-sparse@vger.kernel.org>
Subject: Re: Potential incorrect simplification
Date: Sun, 6 Aug 2017 16:52:55 +0100 [thread overview]
Message-ID: <CACXZuxd30jwczag_GHW3cmqPcBybEi7jfwfku81vW2nHzo_kyA@mail.gmail.com> (raw)
In-Reply-To: <CANeU7QnjRSnnSc8ew69-0M7XP2zoSVh3jhCciYDRVF0i24d=sQ@mail.gmail.com>
Hi,
I would like to assert that in the C code there was no attempt to
access uninitialized value. If you have a look at the original report
here:
http://marc.info/?l=linux-sparse&m=149070715427276&w=2
You will see that the C code assigns a value to the field before
attempting to access it as shown below.
s3.onebit = 1;
if(s3.onebit != 1){
}
It might be useful to step back and explore how should code be
generated for this such that it is not treated as uninitialized value.
Regards
Dibyendu
next prev parent reply other threads:[~2017-08-06 15:52 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-28 12:40 Potential incorrect simplification Dibyendu Majumdar
2017-03-28 13:34 ` Luc Van Oostenryck
2017-03-28 13:58 ` Dibyendu Majumdar
2017-03-28 14:11 ` Luc Van Oostenryck
2017-03-28 14:19 ` Dibyendu Majumdar
2017-03-28 16:20 ` Linus Torvalds
2017-03-28 17:00 ` Luc Van Oostenryck
2017-03-28 18:02 ` Linus Torvalds
2017-03-28 20:27 ` Luc Van Oostenryck
2017-03-28 21:57 ` Linus Torvalds
2017-03-28 22:28 ` Luc Van Oostenryck
2017-03-28 22:22 ` Dibyendu Majumdar
2017-08-06 12:46 ` Christopher Li
2017-08-06 14:00 ` Luc Van Oostenryck
2017-08-06 14:24 ` Christopher Li
2017-08-06 14:54 ` Christopher Li
2017-08-06 15:07 ` Luc Van Oostenryck
2017-08-06 15:51 ` Christopher Li
2017-08-06 16:51 ` Luc Van Oostenryck
2017-08-06 18:35 ` Christopher Li
2017-08-06 19:51 ` Dibyendu Majumdar
2017-08-06 20:08 ` Luc Van Oostenryck
2017-08-06 19:52 ` Luc Van Oostenryck
2017-08-06 23:34 ` Christopher Li
2017-08-07 0:31 ` Luc Van Oostenryck
2017-08-07 0:38 ` Christopher Li
2017-08-06 15:52 ` Dibyendu Majumdar [this message]
2017-08-06 16:56 ` Luc Van Oostenryck
2017-08-06 17:04 ` Dibyendu Majumdar
2017-08-06 17:45 ` Luc Van Oostenryck
2017-08-06 17:58 ` Dibyendu Majumdar
2017-08-06 18:15 ` Luc Van Oostenryck
2017-08-06 18:18 ` Dibyendu Majumdar
2017-08-06 18:31 ` Luc Van Oostenryck
2017-08-07 19:11 ` [PATCH v2 0/8] fix loading of partially defined bitfield Luc Van Oostenryck
2017-08-07 19:11 ` [PATCH v2 1/8] Remove single-store shortcut Luc Van Oostenryck
2017-08-07 21:42 ` Linus Torvalds
2017-08-10 0:29 ` Christopher Li
2017-08-10 0:41 ` Luc Van Oostenryck
2017-08-10 0:53 ` Christopher Li
2017-08-10 11:01 ` Christopher Li
2017-08-10 12:26 ` Luc Van Oostenryck
2017-08-10 13:25 ` Christopher Li
2017-08-07 19:11 ` [PATCH v2 2/8] new helper: def_opcode() Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 3/8] reuse nbr_pseudo_users() Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 4/8] change the masking when loading bitfields Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 5/8] simplify ((A & M') | B ) & M when M' & M == 0 Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 6/8] transform (A & M) >> S to (A >> S) & (M >> S) Luc Van Oostenryck
2017-08-08 0:22 ` Christopher Li
2017-08-08 0:29 ` Luc Van Oostenryck
2017-08-08 1:48 ` Christopher Li
2017-08-08 1:00 ` Linus Torvalds
2017-08-08 1:38 ` Luc Van Oostenryck
2017-08-08 1:50 ` Christopher Li
2017-08-07 19:12 ` [PATCH v2 7/8] transform (A << S) >> S into A & (-1 " Luc Van Oostenryck
2017-08-07 21:54 ` Linus Torvalds
2017-08-07 22:08 ` Luc Van Oostenryck
2017-08-07 22:27 ` Luc Van Oostenryck
2017-08-07 19:12 ` [PATCH v2 8/8] fix: cast of OP_AND only valid if it's an OP_CAST Luc Van Oostenryck
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