Re: ARM/linux gdb stops and gives no info

[Scott Bambrough <scottb@netwinder.org>]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 8533 bytes --]

Richard Earnshaw wrote:

> /usr/include/sys/procfs.h contains an include of sys/elf.h, but this file
> doesn't exist.  Should it be the same as /usr/include/elf.h?

That is a bone head bug on my part.  I forgot to add the file to the make file
so it doesn't install correctly.  Grab the new glibc RPM from netwinder.org.  It
will fix the problem without causing you headaches.

See here:

http://www.netwinder.org/utools.html

Scott

-- 
Scott Bambrough - Software Engineer
REBEL.COM    http://www.rebel.com
NetWinder    http://www.netwinder.org
From obrien@FreeBSD.org Tue May 30 11:54:00 2000
From: "David O'Brien" <obrien@FreeBSD.org>
To: Anatoly Vorobey <mellon@pobox.com>
Cc: Mark Kettenis <kettenis@wins.uva.nl>, gdb@sourceware.cygnus.com
Subject: Re: GDB on FreeBSD/Alpha
Date: Tue, 30 May 2000 11:54:00 -0000
Message-id: <20000530115440.A47686@dragon.nuxi.com>
References: <200005292310.e4TNAoY05799@delius.kettenis.local> <20000529192510.A72082@sasami.jurai.net>
X-SW-Source: 2000-05/msg00166.html
Content-length: 314

On Mon, May 29, 2000 at 07:25:10PM -0400, Anatoly Vorobey wrote:
> I understand that David is going to give us gcc 2.96 on FreeBSD soon.
> Is the bug fixed there?

4.x will probably stay at 2.95.x (especially with no date on 3.0).  Thus
we must work around any bugs in 2.95.x.
 
-- 
-- David  (obrien@FreeBSD.org)
From scottb@netwinder.org Tue May 30 13:35:00 2000
From: Scott Bambrough <scottb@netwinder.org>
To: Fernando Nasser <fnasser@cygnus.com>
Cc: rearnsha@arm.com, Nicolas.Thery@Symbian.com, gdb@sourceware.cygnus.com
Subject: Re: ARM/linux gdb stops and gives no info
Date: Tue, 30 May 2000 13:35:00 -0000
Message-id: <393424E5.EE98700A@netwinder.org>
References: <200005300948.KAA21133@cam-mail2.cambridge.arm.com> <3933C65A.CB1626B1@cygnus.com>
X-SW-Source: 2000-05/msg00167.html
Content-length: 2359

Fernando Nasser wrote:
> 
> I quickly created the patch below.  I have no time to test it these days.
> If you care applying it to your sources and trying I would appreciate.
> Otherwise it goes in my 25 pages long TODO list.. ;-)

I tested the following patch out in the mainline, and it seems to do the trick. 
I will create a new RPM for GDB 5 with this patch today and put in on
netwinder.org for Richard.

Thanks Fernando,

Scott
 
> Index: infcmd.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/infcmd.c,v
> retrieving revision 1.1.1.17
> diff -c -p -r1.1.1.17 infcmd.c
> *** infcmd.c    2000/02/03 04:14:31     1.1.1.17
> --- infcmd.c    2000/05/30 13:42:23
> *************** char *gdb_register_names[] = REGISTER_NA
> *** 1494,1501 ****
>      is required, (eg, for MIPS or Pyramid 90x, which both have
>      lots of regs), or there is an existing convention for showing
>      all the registers, define the macro DO_REGISTERS_INFO(regnum, fp)
> !    to provide that format.  */
> 
>   #if !defined (DO_REGISTERS_INFO)
> 
>   #define DO_REGISTERS_INFO(regnum, fp) do_registers_info(regnum, fp)
> --- 1494,1504 ----
>      is required, (eg, for MIPS or Pyramid 90x, which both have
>      lots of regs), or there is an existing convention for showing
>      all the registers, define the macro DO_REGISTERS_INFO(regnum, fp)
> !    to provide that format.
> 
> +    This default routine must work even if there is no selected_frame (== NULL).
> +    Please don't add any dependencies on that being defined. */
> +
>   #if !defined (DO_REGISTERS_INFO)
> 
>   #define DO_REGISTERS_INFO(regnum, fp) do_registers_info(regnum, fp)
> *************** registers_info (addr_exp, fpregs)
> *** 1617,1624 ****
> --- 1620,1633 ----
> 
>     if (!target_has_registers)
>       error ("The program has no registers now.");
> +
> + #if !defined (DO_REGISTERS_INFO)
> +   /* The default do_registers_info() does not need the selected_frame
> +      so we don't test for it not being NULL. Tagets that define
> +      DO_REGISTERS_INFO may rely on that, so we make sure it is valid. */
>     if (selected_frame == NULL)
>       error ("No selected frame.");
> + #endif
> 
>     if (!addr_exp)
>       {

-- 
Scott Bambrough - Software Engineer
REBEL.COM    http://www.rebel.com
NetWinder    http://www.netwinder.org
From Peter.Schauer@regent.e-technik.tu-muenchen.de Tue May 30 13:46:00 2000
From: "Peter.Schauer" <Peter.Schauer@regent.e-technik.tu-muenchen.de>
To: fnasser@cygnus.com (Fernando Nasser)
Cc: rearnsha@arm.com, Nicolas.Thery@Symbian.com, gdb@sourceware.cygnus.com
Subject: Re: ARM/linux gdb stops and gives no info
Date: Tue, 30 May 2000 13:46:00 -0000
Message-id: <200005302045.WAA16113@reisser.regent.e-technik.tu-muenchen.de>
References: <3933C65A.CB1626B1@cygnus.com>
X-SW-Source: 2000-05/msg00168.html
Content-length: 2577

> > Thanks for the tip: yes, that works.  However, I still think that "info
> > reg" should display the raw registers if there is no valid stack frame.
> > 
> 
> Peter Schauer added the test for NULL frames in there back in 1995.  I believe
> it was causing core dumps, but I am not sure as the ChangeLog entry does not give
> the motive (we nowadays make sure it does, but that was not always true at the time):
> 
>      * infcmd.c (registers_info):  Error out if selected_frame is NULL.

It was a safety measure to avoid GDB core dumps if selected_frame == NULL.
If you really want to reproduce the original problem, get gdb-4.15.1, build
it on sparc Solaris and (mostly from the original bug report):

        ./gdb ./gdb     <- Freshly compiled 4.15.1 on itself
	set auto 0	(to avoid problems with /usr/platform/* sym reading)
        run
        info            <- pops you back to top level gdb
        info stack      <- Shows frames
        info registers  <- Kuh-BOOM, monster core dump in progress.

Back then, info stack left selected_frame == NULL, and then GDB crashed in

#0  0x70ef4 in get_saved_register (raw_buffer=0xeffff030 "ïÿï°",
    optimized=0xefffefa4, addrp=0x0, frame=0x0, regnum=0x0, lval=0x0)
    at ../../gdb-4.15.1/gdb/sparc-tdep.c:610
#1  0x30a80 in read_relative_register_raw_bytes (regnum=0x0,
    myaddr=0xeffff030 "ïÿï°") at ../../gdb-4.15.1/gdb/findvar.c:433
#2  0x6137c in do_registers_info (regnum=0xffffffff, fpregs=0x0)
    at ../../gdb-4.15.1/gdb/infcmd.c:980
#3  0x61734 in registers_info (addr_exp=0x0, fpregs=0x0)

> I believe the default gdb routine (if the target does not define DO_REGISTERS_INFO)
> does not depend on selected_frame but I can't be sure about all targets.
> I quickly created the patch below.  I have no time to test it these days.

With CVS GDB, do_registers_info calls read_relative_register_raw_bytes
which in turn calls read_relative_register_raw_bytes_for_frame with
selected_frame.

So even nowadays generic do_registers_info might need a valid selected_frame,
and your proposed patch would not help.

I'd prefer to keep the selected_frame != NULL check in registers_info
and rather make sure that selected_frame is not NULL in Richard's case,
although I do not know if this can be done for the ARM.

On the other hand we could remove the check in registers_info and wait for
bug reports with GDB crashing in registers_info due to selected_frame == NULL
and fix their cause.

Has to be decided by the maintainer of infcmd.c (Fernando ? :-).

-- 
Peter Schauer			pes@regent.e-technik.tu-muenchen.de
From fred_finster@el.nec.com Tue May 30 15:19:00 2000
From: "Fred Finster" <fred_finster@el.nec.com>
To: <gdb@sourceware.cygnus.com>
Cc: <Bob_Delp@el.nec.com>
Subject: CYGMON source code CVS source tree availability for NEC Vr4300  or NEC Vr4121 CPUs?
Date: Tue, 30 May 2000 15:19:00 -0000
Message-id: <001a01bfca84$cf14bd80$1c017ec0@ffinster-nt.el.nec.com>
X-SW-Source: 2000-05/msg00169.html
Content-length: 799

Hello fellow open source supporters.  Thank you for taking time to read this
and possible provide me a couple hints regarding the  "fill in the blank"
questions below.

I am new to this group.  Yes, I should read the web page,  __XXXX__, on how
to get
the, ??ECOS?? source, that has inside the files to build cygmon EPROM.
Just customize
the files, ___XXXX.h & ___XXXX.h & crt0.S and say "make cygmon".

I did search  for "cygmon" on the http://sourceware.cygnus.com/ecos
webpage
and came up with 83 hits.   Lots of good technical explanations, but I
missed
the obvious pointer to the source code availability.    Your short helpful
hints will be most appreciated.  Thank you

Fred Finster
NEC Electronics
MS  SC2202
PO Box 58062
Santa Clara CA 950502

(408) 588-5726
AIM screen name: WB7ODYFred