Re: [bug, bisected, -chrisl] Segfault at evaluate.c:341

[Nicholas Mc Guire <der.herr@hofr.at>]

On Thu, 19 Mar 2009, Al Viro wrote:

> On Thu, Mar 19, 2009 at 02:49:21PM +0100, Hannes Eder wrote:
> > running sparse (from Christopher's tree) on linux-2.6/kernel/cred.c
> > (as of next-20090318, problem may appeared earlier, I have not tried
> > yet) causes a segfault at evaluate.c:341:
> > 
> >         if (type->type == SYM_NODE)
> >                 type = type->ctype.base_type;
> >         if (type->type == SYM_TYPEOF) {        <======== SEGFAULT (type == NULL)
> >                 type = evaluate_expression(type->initializer);
> >                 if (type->type == SYM_NODE)
> >                         type = type->ctype.base_type;
> >         }
> > 
> > the complete command line:
> > 
> > sparse -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise
> > -Wno-return-void -D__x86_64__ -m64 -nostdinc -isystem
> > /usr/lib/gcc/x86_64-redhat-linux/4.3.2/include
> > -Wp,-MD,kernel/.cred.o.d -nostdinc -isystem
> > /usr/lib/gcc/x86_64-redhat-linux/4.3.2/include -Iinclude
> > -I/home/hannes/linux-2.6/arch/x86/include -include
> > include/linux/autoconf.h -D__KERNEL__ -Wall -Wundef
> > -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common
> > -Werror-implicit-function-declaration -Os -m64 -mtune=generic
> > -mno-red-zone -mcmodel=kernel -funit-at-a-time
> > -maccumulate-outgoing-args -fstack-protector -fstack-protector-all
> > -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -pipe
> > -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx
> > -mno-sse2 -mno-3dnow -fno-omit-frame-pointer
> > -fno-optimize-sibling-calls -g -pg -Wdeclaration-after-statement
> > -Wno-pointer-sign -D"KBUILD_STR(s)=#s"
> > -D"KBUILD_BASENAME=KBUILD_STR(cred)"
> > -D"KBUILD_MODNAME=KBUILD_STR(cred)" -D"DEBUG_HASH=36"
> > -D"DEBUG_HASH2=28" kernel/cred.c
> > 
> > 
> > using "git bisect" i narrowed to problem down to:
> > 
> > [db31fd91f8231110ce8d8d48ce402f8cad068e44] Fix handling of ident-less
> > declarations
> > 
> > Does that help? Should I provide any further information?
> 
> Preprocessed input would help (note that knowing the kernel tree in
> question is not enough - .config affects what comes out of preprocessing,
> after all).
>
> Just slap -E in command line above and dump the output someplace public...

just to (hopfully) simplify things a bit - a simple:

make i386_defconfig
make V=1 C=1 kernel/kred.i 

should actually do it 

hofrat