Re: kern/57564 gdb netbsd.gdb and vfs_cache.o file

[Ramiro Aceves <ea1abz%gmail.com@localhost>]

Hello Taylor, thanks for help. Please see below:

El 9/8/23 a las 9:21, Taylor R Campbell escribió:
> This is very weird...  The relevant code is this:
>
> #define	COUNT(f) do { \
> 	lwp_t *l = curlwp; \
> 	KPREEMPT_DISABLE(l); \
> 	struct nchcpu *nchcpu = curcpu()->ci_data.cpu_nch; \
> 	nchcpu->cur.f++; \
> 	KPREEMPT_ENABLE(l); \
> } while (/* CONSTCOND */ 0);
>
> Somewhere, between
>
> 	lwp_t *l = curlwp;
>
> and
>
> 	KPREEMPT_DISABLE(l);
>
> l has become null.  My first guess would be that the exception vector
> failed to restore all the registers or something.  But every time it's
> tripped exactly the same assertion, with the same stack trace in
> cache_lookup, right?  If the exception vector were broken, I would
> expect to see other random things failing or panicking.
>
> Can you send me the vfs_cache.o file from your kernel build, and/or
> share the output of `list *(cache_lookup+0x7c0)' in `gdb netbsd.gdb'?
> Maybe the compiler has done something screwy here on armv6.

ramiro@debian-nuc8i7:~/cvs/src/sys/arch/evbarm/compile/MYKERNEL$ gdb 
netbsd.gdb
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warning: A handler for the OS ABI "NetBSD" is not built into this 
configuration
of GDB.  Attempting to continue with the default i386 settings.

Reading symbols from netbsd.gdb...
warning: File 
"/home/ramiro/cvs/src/sys/arch/evbarm/compile/MYKERNEL/.gdbinit" 
auto-loading has been declined by your `auto-load safe-path' set to 
"$debugdir:$datadir/auto-load".
To enable execution of this file add
	add-auto-load-safe-path 
/home/ramiro/cvs/src/sys/arch/evbarm/compile/MYKERNEL/.gdbinit
line to your configuration file "/home/ramiro/.config/gdb/gdbinit".
To completely disable this security protection add
	set auto-load safe-path /
line to your configuration file "/home/ramiro/.config/gdb/gdbinit".
For more information about this security protection see the
"Auto-loading safe path" section in the GDB manual.  E.g., run from the 
shell:
	info "(gdb)Auto-loading safe path"
(gdb) list *(cache_lookup+0x7c0)
0x80437ebc is in cache_lookup (../../../../sys/lwp.h:544).
539	static __inline void
540	KPREEMPT_DISABLE(lwp_t *l)
541	{
542		struct lwp *l1 __diagused;
543	
544		KASSERTMSG(l == (l1 = curlwp), "l=%p curlwp=%p", l, l1);
545		l->l_nopreempt++;
546		__insn_barrier();
547	}
548	
(gdb)


I attach vfs_cache.o file

Thanks

Attachment: vfs_cache.o
Description: application/object