* [RFA] Find and read symbol files after attach (linux)
@ 2002-01-07 18:20 Michael Snyder
2002-01-07 19:00 ` Daniel Jacobowitz
0 siblings, 1 reply; 6+ messages in thread
From: Michael Snyder @ 2002-01-07 18:20 UTC (permalink / raw)
To: gdb-patches; +Cc: drow, kettenis, kevinb
[oops, hit send too soon...]
This change allows GDB to find and read the symbol files (including
all shared libraries) on Linux when you attach to an anonymous PID.
It should work for all Linuxen, but for now I've only added it to the
linux.mh and nm-linux.h files in config/i386. Please feel free to
add it to your targets.
(gdb) attach 29962
Attaching to process 29962
Reading symbols from /builds/native/gdb/testsuite/foo...
done.
Reading symbols from /lib/i686/libc.so.6...done.
Loaded symbols for /lib/i686/libc.so.6
Reading symbols from /lib/ld-linux.so.2...done.
Loaded symbols for /lib/ld-linux.so.2
0x400dc8e1 in __libc_nanosleep () from /lib/i686/libc.so.6
(gdb) backtrace
#0 0x400dc8e1 in __libc_nanosleep () from /lib/i686/libc.so.6
#1 0x400dc761 in __sleep (seconds=1) at ../sysdeps/unix/sysv/linux/sleep.c:85
#2 0x08048482 in main () at foo.c:5
#3 0x4003e177 in __libc_start_main (main=0x8048460 <main>, argc=1,
ubp_av=0xbffff51c, init=0x80482e0 <_init>, fini=0x80484d0 <_fini>,
rtld_fini=0x4000e184 <_dl_fini>, stack_end=0xbffff50c)
at ../sysdeps/generic/libc-start.c:129
(gdb)
2002-01-07 Michael Snyder <msnyder@redhat.com>
* linux-proc.c: New file. Implement proc_iterate_over_mappings
and child_pid_to_exec_file, so that attaching to a pid will
automatically read the process's symbol file and shlibs.
* config/i386/linux.mh: Add linux-proc.o to NATDEPFILES.
* config/i386/nm-linux.h: Define CHILD_PID_TO_EXEC_FILE
and HANDLE_SVR4_EXEC_EMULATORS (FIXME not a good name).
Index: linux-proc.c
===================================================================
RCS file: linux-proc.c
diff -N linux-proc.c
*** /dev/null Tue May 5 13:32:27 1998
--- linux-proc.c Mon Jan 7 16:34:05 2002
***************
*** 0 ****
--- 1,90 ----
+ /* Generate a core file for the inferior process -- Linux version.
+ Copyright 2001 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+ #include "defs.h"
+ #include "inferior.h"
+ #include <sys/param.h> /* for MAXPATHLEN */
+ #include <sys/procfs.h>
+ #include <fcntl.h> /* for O_RDONLY */
+
+ /* Linux version of "proc_iterate_over_mappings". */
+
+ int
+ read_mapping (FILE *mapfile,
+ long long *addr,
+ long long *endaddr,
+ char *permissions,
+ long long *offset,
+ char *device,
+ long long *inode,
+ char *filename)
+ {
+ int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
+ addr, endaddr, permissions, offset, device, inode);
+
+ if (ret > 0 && ret != EOF && *inode != 0)
+ {
+ ret += fscanf (mapfile, "%s\n", filename);
+ }
+ else
+ {
+ filename[0] = '\0'; /* no filename */
+ fscanf (mapfile, "\n");
+ }
+ return (ret != 0 && ret != EOF);
+ }
+
+ int
+ proc_iterate_over_mappings (int (*func) (int, CORE_ADDR))
+ {
+ long long pid = PIDGET (inferior_ptid);
+ char procfilename[MAXPATHLEN];
+ FILE *mapsfile;
+ long long addr, endaddr, size, offset, inode;
+ char permissions[8], device[8], filename [MAXPATHLEN];
+ int funcret = 0;
+
+ /* Compose the filename for the /proc memory map, and open it. */
+ sprintf (procfilename, "/proc/%lld/maps", pid);
+ if ((mapsfile = fopen (procfilename, "r")) == NULL)
+ error ("Could not open %s\n", procfilename);
+
+ while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
+ &offset, &device[0], &inode, &filename[0]))
+ {
+ if (filename[0])
+ {
+ int fd = open (filename, O_RDONLY);
+ if ((funcret = func (fd, (CORE_ADDR) addr)) != 0)
+ break;
+ }
+ }
+ fclose (mapsfile);
+ return funcret;
+ }
+
+ char *
+ child_pid_to_exec_file (int pid)
+ {
+ static char fname[MAXPATHLEN];
+
+ sprintf (fname, "/proc/%d/exe", pid);
+ return fname;
+ }
Index: config/i386/nm-linux.h
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/nm-linux.h,v
retrieving revision 1.15
diff -c -3 -p -r1.15 nm-linux.h
*** nm-linux.h 2001/10/14 20:42:07 1.15
--- nm-linux.h 2002/01/08 00:34:05
*************** extern int cannot_store_register (int re
*** 80,83 ****
--- 80,89 ----
/* Override child_resume in `infptrace.c'. */
#define CHILD_RESUME
+ /* Override child_pid_to_exec_file in 'inftarg.c'. */
+ #define CHILD_PID_TO_EXEC_FILE
+
+ /* Enable handling of shared libraries for a.out executables. */
+ #define HANDLE_SVR4_EXEC_EMULATORS
+
#endif /* nm-linux.h */
Index: config/i386/linux.mh
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/linux.mh,v
retrieving revision 1.8
diff -c -3 -p -r1.8 linux.mh
*** linux.mh 2001/07/31 19:22:57 1.8
--- linux.mh 2002/01/08 00:34:05
*************** XDEPFILES=
*** 6,12 ****
NAT_FILE= nm-linux.h
NATDEPFILES= infptrace.o inftarg.o fork-child.o corelow.o \
core-aout.o i386-nat.o i386-linux-nat.o i387-nat.o \
! proc-service.o thread-db.o lin-lwp.o
# The dynamically loaded libthread_db needs access to symbols in the
# gdb executable.
--- 6,12 ----
NAT_FILE= nm-linux.h
NATDEPFILES= infptrace.o inftarg.o fork-child.o corelow.o \
core-aout.o i386-nat.o i386-linux-nat.o i387-nat.o \
! proc-service.o thread-db.o lin-lwp.o linux-proc.o
# The dynamically loaded libthread_db needs access to symbols in the
# gdb executable.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFA] Find and read symbol files after attach (linux)
2002-01-07 18:20 [RFA] Find and read symbol files after attach (linux) Michael Snyder
@ 2002-01-07 19:00 ` Daniel Jacobowitz
2002-01-08 10:12 ` Mark Kettenis
[not found] ` <3C3B332E.774C4E2E@redhat.com>
0 siblings, 2 replies; 6+ messages in thread
From: Daniel Jacobowitz @ 2002-01-07 19:00 UTC (permalink / raw)
To: Michael Snyder; +Cc: gdb-patches, kettenis, kevinb
On Mon, Jan 07, 2002 at 04:40:00PM -0800, Michael Snyder wrote:
> [oops, hit send too soon...]
> This change allows GDB to find and read the symbol files (including
> all shared libraries) on Linux when you attach to an anonymous PID.
> It should work for all Linuxen, but for now I've only added it to the
> linux.mh and nm-linux.h files in config/i386. Please feel free to
> add it to your targets.
[without actually looking at it...]
(A) Is there any reason not to do it for all Linuxen in
config/nm-linux.h?
(B) Why do we need /proc to do this? We should be able to use the
information in the link map - which we already access in solib-svr4.h -
to get all of this.
I've got nothing against adding linux /proc support, but I don't see
why it's needed for this.
--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFA] Find and read symbol files after attach (linux)
2002-01-07 19:00 ` Daniel Jacobowitz
@ 2002-01-08 10:12 ` Mark Kettenis
[not found] ` <3C3B332E.774C4E2E@redhat.com>
1 sibling, 0 replies; 6+ messages in thread
From: Mark Kettenis @ 2002-01-08 10:12 UTC (permalink / raw)
To: drow; +Cc: msnyder, gdb-patches, kevinb
Date: Mon, 7 Jan 2002 21:59:57 -0500
From: Daniel Jacobowitz <drow@mvista.com>
Cc: gdb-patches@sources.redhat.com, kettenis@science.uva.nl, kevinb@redhat.com
Mail-Followup-To: Michael Snyder <msnyder@cygnus.com>,
gdb-patches@sources.redhat.com, kettenis@science.uva.nl,
kevinb@redhat.com
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.3.23i
X-Status:
X-Keywords:
X-UID: 16
On Mon, Jan 07, 2002 at 04:40:00PM -0800, Michael Snyder wrote:
> [oops, hit send too soon...]
> This change allows GDB to find and read the symbol files (including
> all shared libraries) on Linux when you attach to an anonymous PID.
> It should work for all Linuxen, but for now I've only added it to the
> linux.mh and nm-linux.h files in config/i386. Please feel free to
> add it to your targets.
[without actually looking at it...]
[...for both of us]
(B) Why do we need /proc to do this? We should be able to use the
information in the link map - which we already access in solib-svr4.h -
to get all of this.
Nope. You can't get at the executable itself this way.
Mark
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFA] Find and read symbol files after attach (linux)
[not found] ` <3C3B332E.774C4E2E@redhat.com>
@ 2002-01-08 10:36 ` Daniel Jacobowitz
2002-01-08 15:15 ` Michael Snyder
0 siblings, 1 reply; 6+ messages in thread
From: Daniel Jacobowitz @ 2002-01-08 10:36 UTC (permalink / raw)
To: Michael Snyder; +Cc: gdb-patches, kettenis, kevinb
On Tue, Jan 08, 2002 at 09:58:06AM -0800, Michael Snyder wrote:
> Daniel Jacobowitz wrote:
> >
> > On Mon, Jan 07, 2002 at 04:40:00PM -0800, Michael Snyder wrote:
> > > [oops, hit send too soon...]
> > > This change allows GDB to find and read the symbol files (including
> > > all shared libraries) on Linux when you attach to an anonymous PID.
> > > It should work for all Linuxen, but for now I've only added it to the
> > > linux.mh and nm-linux.h files in config/i386. Please feel free to
> > > add it to your targets.
> >
> > [without actually looking at it...]
> >
> > (A) Is there any reason not to do it for all Linuxen in
> > config/nm-linux.h?
>
> Probably can. I was being conservative.
I'd prefer you to do this, then. I believe it will work.
> > (B) Why do we need /proc to do this? We should be able to use the
> > information in the link map - which we already access in solib-svr4.h -
> > to get all of this.
>
> There may be another method of doing it -- I just used the
> method I know (copied from Solaris). We need to discover
> the mapped memory regions so you can find the "debug_base".
> But this isn't one of my strong areas, so you may well know
> a better way to do the same thing.
Well, Mark's comment is completely correct. Eventually I remembered
that this works by looking up data at _DYNAMIC, which means we need the
executable first :)
I believe that we should be able to find the rest of what we need by
the shared library code, without the mappings file, though. I also
thought that this would just 'work'. Have you tried with the code to
find the executable but without the code to find shared libraries?
What happens?
--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFA] Find and read symbol files after attach (linux)
2002-01-08 10:36 ` Daniel Jacobowitz
@ 2002-01-08 15:15 ` Michael Snyder
0 siblings, 0 replies; 6+ messages in thread
From: Michael Snyder @ 2002-01-08 15:15 UTC (permalink / raw)
To: gdb-patches
Daniel Jacobowitz wrote:
>
> On Tue, Jan 08, 2002 at 09:58:06AM -0800, Michael Snyder wrote:
> > Daniel Jacobowitz wrote:
> > >
> > > On Mon, Jan 07, 2002 at 04:40:00PM -0800, Michael Snyder wrote:
> > > > [oops, hit send too soon...]
> > > > This change allows GDB to find and read the symbol files (including
> > > > all shared libraries) on Linux when you attach to an anonymous PID.
> > > > It should work for all Linuxen, but for now I've only added it to the
> > > > linux.mh and nm-linux.h files in config/i386. Please feel free to
> > > > add it to your targets.
> > >
> > > [without actually looking at it...]
> > >
> > > (A) Is there any reason not to do it for all Linuxen in
> > > config/nm-linux.h?
> >
> > Probably can. I was being conservative.
>
> I'd prefer you to do this, then. I believe it will work.
>
> > > (B) Why do we need /proc to do this? We should be able to use the
> > > information in the link map - which we already access in solib-svr4.h -
> > > to get all of this.
> >
> > There may be another method of doing it -- I just used the
> > method I know (copied from Solaris). We need to discover
> > the mapped memory regions so you can find the "debug_base".
> > But this isn't one of my strong areas, so you may well know
> > a better way to do the same thing.
>
> Well, Mark's comment is completely correct. Eventually I remembered
> that this works by looking up data at _DYNAMIC, which means we need the
> executable first :)
>
> I believe that we should be able to find the rest of what we need by
> the shared library code, without the mappings file, though. I also
> thought that this would just 'work'. Have you tried with the code to
> find the executable but without the code to find shared libraries?
> What happens?
Oops, I answered "yes, it works", but my email is out to lunch.
Yes, it works. Submitted separately, approved, and checked in.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [RFA] Find and read symbol files after attach (linux)
@ 2002-01-07 18:20 Michael Snyder
0 siblings, 0 replies; 6+ messages in thread
From: Michael Snyder @ 2002-01-07 18:20 UTC (permalink / raw)
To: gdb-patches; +Cc: kettenis, kevinb
This change allows GDB to find and read the symbol files (including
all shared libraries) on Linux when you attach to an anonymous PID.
It should work for all Linuxen, but for now I've only added it to the
linux.mh and nm-linux.h files in config/i386. Please feel free to
add it to your targets.
(gdb) attach 29962
Attaching to process 29962
Reading symbols from /builds/native/gdb/testsuite/foo...
done.
Reading symbols from /lib/i686/libc.so.6...done.
Loaded symbols for /lib/i686/libc.so.6
Reading symbols from /lib/ld-linux.so.2...done.
Loaded symbols for /lib/ld-linux.so.2
0x400dc8e1 in __libc_nanosleep () from /lib/i686/libc.so.6
(gdb) backtrace
#0 0x400dc8e1 in __libc_nanosleep () from /lib/i686/libc.so.6
#1 0x400dc761 in __sleep (seconds=1) at ../sysdeps/unix/sysv/linux/sleep.c:85
#2 0x08048482 in main () at foo.c:5
#3 0x4003e177 in __libc_start_main (main=0x8048460 <main>, argc=1,
ubp_av=0xbffff51c, init=0x80482e0 <_init>, fini=0x80484d0 <_fini>,
rtld_fini=0x4000e184 <_dl_fini>, stack_end=0xbffff50c)
at ../sysdeps/generic/libc-start.c:129
(gdb)
2002-01-07 Michael Snyder <msnyder@redhat.com>
* linux-proc.c: New file. Implement proc_iterate_over_mappings
and child_pid_to_exec_file, so that attaching to a pid will
automatically read the process's symbol file and shlibs.
* config/i386/linux.mh: Add linux-proc.o to NATDEPFILES.
* config/i386/nm-linux.h: Define CHILD_PID_TO_EXEC_FILE
and HANDLE_SVR4_EXEC_EMULATORS (FIXME not a good name).
Index: linux-proc.c
===================================================================
RCS file: linux-proc.c
diff -N linux-proc.c
*** /dev/null Tue May 5 13:32:27 1998
--- linux-proc.c Mon Jan 7 16:34:05 2002
***************
*** 0 ****
--- 1,90 ----
+ /* Generate a core file for the inferior process -- Linux version.
+ Copyright 2001 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+ #include "defs.h"
+ #include "inferior.h"
+ #include <sys/param.h> /* for MAXPATHLEN */
+ #include <sys/procfs.h>
+ #include <fcntl.h> /* for O_RDONLY */
+
+ /* Linux version of "proc_iterate_over_mappings". */
+
+ int
+ read_mapping (FILE *mapfile,
+ long long *addr,
+ long long *endaddr,
+ char *permissions,
+ long long *offset,
+ char *device,
+ long long *inode,
+ char *filename)
+ {
+ int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx",
+ addr, endaddr, permissions, offset, device, inode);
+
+ if (ret > 0 && ret != EOF && *inode != 0)
+ {
+ ret += fscanf (mapfile, "%s\n", filename);
+ }
+ else
+ {
+ filename[0] = '\0'; /* no filename */
+ fscanf (mapfile, "\n");
+ }
+ return (ret != 0 && ret != EOF);
+ }
+
+ int
+ proc_iterate_over_mappings (int (*func) (int, CORE_ADDR))
+ {
+ long long pid = PIDGET (inferior_ptid);
+ char procfilename[MAXPATHLEN];
+ FILE *mapsfile;
+ long long addr, endaddr, size, offset, inode;
+ char permissions[8], device[8], filename [MAXPATHLEN];
+ int funcret = 0;
+
+ /* Compose the filename for the /proc memory map, and open it. */
+ sprintf (procfilename, "/proc/%lld/maps", pid);
+ if ((mapsfile = fopen (procfilename, "r")) == NULL)
+ error ("Could not open %s\n", procfilename);
+
+ while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0],
+ &offset, &device[0], &inode, &filename[0]))
+ {
+ if (filename[0])
+ {
+ int fd = open (filename, O_RDONLY);
+ if ((funcret = func (fd, (CORE_ADDR) addr)) != 0)
+ break;
+ }
+ }
+ fclose (mapsfile);
+ return funcret;
+ }
+
+ char *
+ child_pid_to_exec_file (int pid)
+ {
+ static char fname[MAXPATHLEN];
+
+ sprintf (fname, "/proc/%d/exe", pid);
+ return fname;
+ }
Index: config/i386/nm-linux.h
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/nm-linux.h,v
retrieving revision 1.15
diff -c -3 -p -r1.15 nm-linux.h
*** nm-linux.h 2001/10/14 20:42:07 1.15
--- nm-linux.h 2002/01/08 00:34:05
*************** extern int cannot_store_register (int re
*** 80,83 ****
--- 80,89 ----
/* Override child_resume in `infptrace.c'. */
#define CHILD_RESUME
+ /* Override child_pid_to_exec_file in 'inftarg.c'. */
+ #define CHILD_PID_TO_EXEC_FILE
+
+ /* Enable handling of shared libraries for a.out executables. */
+ #define HANDLE_SVR4_EXEC_EMULATORS
+
#endif /* nm-linux.h */
Index: config/i386/linux.mh
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/linux.mh,v
retrieving revision 1.8
diff -c -3 -p -r1.8 linux.mh
*** linux.mh 2001/07/31 19:22:57 1.8
--- linux.mh 2002/01/08 00:34:05
*************** XDEPFILES=
*** 6,12 ****
NAT_FILE= nm-linux.h
NATDEPFILES= infptrace.o inftarg.o fork-child.o corelow.o \
core-aout.o i386-nat.o i386-linux-nat.o i387-nat.o \
! proc-service.o thread-db.o lin-lwp.o
# The dynamically loaded libthread_db needs access to symbols in the
# gdb executable.
--- 6,12 ----
NAT_FILE= nm-linux.h
NATDEPFILES= infptrace.o inftarg.o fork-child.o corelow.o \
core-aout.o i386-nat.o i386-linux-nat.o i387-nat.o \
! proc-service.o thread-db.o lin-lwp.o linux-proc.o
# The dynamically loaded libthread_db needs access to symbols in the
# gdb executable.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2002-01-08 23:15 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2002-01-07 18:20 [RFA] Find and read symbol files after attach (linux) Michael Snyder
2002-01-07 19:00 ` Daniel Jacobowitz
2002-01-08 10:12 ` Mark Kettenis
[not found] ` <3C3B332E.774C4E2E@redhat.com>
2002-01-08 10:36 ` Daniel Jacobowitz
2002-01-08 15:15 ` Michael Snyder
2002-01-07 18:20 Michael Snyder
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