linux-kernel - Re: sparse breakage triggered by rcu_read

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <47179ABB.9060104@freedesktop.org>
Date:	Thu, 18 Oct 2007 10:41:15 -0700
From:	Josh Triplett <josh@...edesktop.org>
To:	Alexey Dobriyan <adobriyan@...ru>
CC:	linux-sparse@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: sparse breakage triggered by rcu_read_lock() lockdep annotations

Alexey Dobriyan wrote:
> FWIW, commit 851a67b825540a8e00c0be3ee25e4627ba8b133b
> aka "lockdep: annotate rcu_read_{,un}lock{,_bh}"
> causes sparse to trigger internal assertion in quite a few places over
> allyesconfig run.
> 
> 	sparse: flow.c:805: rewrite_parent_branch: Assertion `changed' failed.
> 
> Trimmed down testcase:
> 
> 	void f(unsigned long ip);
> 	static void g(void)
> 	{
> 	        if (1) {
> 	              f(({ __label__ x; x: (unsigned long)&&x; }));
> 	        }
> 	        f(({ __label__ x; x: (unsigned long)&&x; }));
> 	}
> 
> #0  0x4001c410 in __kernel_vsyscall ()
> (gdb) bt
> #0  0x4001c410 in __kernel_vsyscall ()
> #1  0x40050701 in raise () from /lib/libc.so.6
> #2  0x40051e38 in abort () from /lib/libc.so.6
> #3  0x40049fcc in __assert_fail () from /lib/libc.so.6
> #4  0x08064947 in pack_basic_blocks (ep=0x411a1c6c) at flow.c:812
> #5  0x0805ffbf in linearize_symbol (sym=0x4103ec8c) at linearize.c:2154
> #6  0x080492a3 in main (argc=Cannot access memory at address 0x274d) at sparse.c:266

Thanks for the detailed report.  Looking into it now.

- Josh Triplett



Download attachment "signature.asc" of type "application/pgp-signature" (253 bytes)