Date: Fri, 7 Feb 2003 12:42:44 +0000 From: Peter Edwards <peter.edwards@openet-telecom.com> To: freebsd-current@freebsd.org Subject: [resend] gdb, threads, and corefiles Message-ID: <20030207124244.74bf9df7.peter.edwards@openet-telecom.com>
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Sorry if this appears twice: my webmail client appears to have dropped
the original message on the floor.
gdb didn't find threads in corefiles: The support was just missing.
The attached patch does the job.
Also attached is a small test program which easily generates a corefile
with threads in it, if anyone wants to test/commit it.
Before and after output below:
> petere@rocklobster$ cc -o threadcore -Wall -g -pthread threadcore.c
> petere@rocklobster$ ./threadcore
> started thread 0
> started thread 1
> started thread 2
> started thread 3
> zsh: bus error (core dumped) ./threadcore
> petere@rocklobster$ gdb threadcore threadcore.core
> GNU gdb 5.2.1 (FreeBSD)
> Copyright 2002 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you
> are welcome to change it and/or distribute copies of it under certain
> conditions. Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB. Type "show warranty" for
> details. This GDB was configured as "i386-undermydesk-freebsd"...
> Core was generated by `threadcore'.
> Program terminated with signal 10, Bus error.
> Reading symbols from /usr/lib/libc_r.so.5...done.
> Loaded symbols for /usr/lib/libc_r.so.5
> Reading symbols from /usr/lib/libc.so.5...done.
> Loaded symbols for /usr/lib/libc.so.5
> Reading symbols from /usr/libexec/ld-elf.so.1...done.
> Loaded symbols for /usr/libexec/ld-elf.so.1
> #0 0x280d5463 in kill () from /usr/lib/libc.so.5
> (gdb) i thr
> * 1 process 41359 0x280d5463 in kill () from /usr/lib/libc.so.5
> (gdb) quit
> petere@rocklobster$ /usr/src/gnu/usr.bin/binutils/gdb/gdb threadcore
> threadcore.core GNU gdb 5.2.1 (FreeBSD)
> Copyright 2002 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you
> are welcome to change it and/or distribute copies of it under certain
> conditions. Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB. Type "show warranty" for
> details. This GDB was configured as "i386-undermydesk-freebsd"...
> Core was generated by `threadcore'.
> Program terminated with signal 10, Bus error.
> Reading symbols from /usr/lib/libc_r.so.5...done.
> Loaded symbols for /usr/lib/libc_r.so.5
> Reading symbols from /usr/lib/libc.so.5...done.
> Loaded symbols for /usr/lib/libc.so.5
> Reading symbols from /usr/libexec/ld-elf.so.1...done.
> Loaded symbols for /usr/libexec/ld-elf.so.1
> #0 0x280d5463 in kill () from /usr/lib/libc.so.5
> (gdb) i thr
> 7 Process 41359 0x280d5463 in kill () from /usr/lib/libc.so.5
> 6 Process 41359 0x2807b7ec in _thread_kern_sched () from
> /usr/lib/libc_r.so.5 5 Process 41359 0x2807b7ec in _thread_kern_sched
> () from /usr/lib/libc_r.so.5 4 Process 41359 0x2807b7ec in
> _thread_kern_sched () from /usr/lib/libc_r.so.5 3 Process 41359
> 0x2807b7ec in _thread_kern_sched () from /usr/lib/libc_r.so.5 2
> Process 41359 0x2807b7ec in _thread_kern_sched () from
> /usr/lib/libc_r.so.5
> * 1 Process 41359 0x280d5463 in kill () from /usr/lib/libc.so.5
> (gdb)
Enjoy,
Peter.
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#include <sys/types.h>
#include <signal.h>
#include <pthread.h>
#include <unistd.h>
#include <stdio.h>
#include <err.h>
void *thr(void *a)
{
printf("started thread %d\n", (int)a);
pause();
return 0;
}
int main(int argc, char **argv)
{
const int THREADCOUNT = 4;
int i;
pthread_t threads[THREADCOUNT];
for (i = 0; i < THREADCOUNT; i++)
if (pthread_create(&threads[i], 0, thr, (void *)i) != 0)
errx(-1, "cannot create thread");
sleep(1);
kill(0, SIGBUS);
return 0;
}
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Index: freebsd-uthread.c
===================================================================
RCS file: /pub/FreeBSD/development/FreeBSD-CVS/src/gnu/usr.bin/binutils/gdb/freebsd-uthread.c,v
retrieving revision 1.10
diff -u -r1.10 freebsd-uthread.c
--- freebsd-uthread.c 4 Jan 2003 17:35:54 -0000 1.10
+++ freebsd-uthread.c 7 Feb 2003 12:34:19 -0000
@@ -46,6 +46,10 @@
#include <sys/stat.h>
#include "gdbcore.h"
+int coreops_suppress_target = 1; /* Ugh. Override the version in corelow.c. */
+extern struct target_ops core_ops; /* target vector for corelow.c */
+static struct target_ops orig_core_ops; /* target vector for corelow.c */
+
extern int child_suppress_run;
extern struct target_ops child_ops; /* target vector for inftarg.c */
@@ -60,6 +64,7 @@
/* Pointer to the next function on the objfile event chain. */
static void (*target_new_objfile_chain) (struct objfile *objfile);
+static void freebsd_uthread_find_new_threads (void);
static void freebsd_uthread_resume PARAMS ((ptid_t pid, int step,
enum target_signal signo));
@@ -472,7 +477,10 @@
if (freebsd_uthread_attaching || TIDGET(inferior_ptid) == 0)
{
- child_ops.to_fetch_registers (regno);
+ if (target_has_execution)
+ child_ops.to_fetch_registers (regno);
+ else
+ orig_core_ops.to_fetch_registers (regno);
return;
}
@@ -481,7 +489,10 @@
if (active)
{
- child_ops.to_fetch_registers (regno);
+ if (target_has_execution)
+ child_ops.to_fetch_registers (regno);
+ else
+ orig_core_ops.to_fetch_registers (regno);
return;
}
@@ -501,8 +512,12 @@
for (regno = first_regno; regno <= last_regno; regno++)
{
- if (regmap[regno] == -1)
- child_ops.to_fetch_registers (regno);
+ if (regmap[regno] == -1) {
+ if (target_has_execution)
+ child_ops.to_fetch_registers (regno);
+ else
+ orig_core_ops.to_fetch_registers (regno);
+ }
else
if (thread)
supply_register (regno, (char*) ®base[regmap[regno]]);
@@ -683,6 +698,11 @@
LOOKUP_VALUE(PS_RUNNING);
LOOKUP_VALUE(PS_DEAD);
+ if (!target_has_execution) {
+ read_thread_offsets();
+ freebsd_uthread_find_new_threads();
+ }
+
freebsd_uthread_active = 1;
}
@@ -731,6 +751,27 @@
return ret;
}
+static int
+freebsd_utcore_thread_alive (ptid_t ptid)
+{
+ return 1;
+}
+
+static void
+freebsd_utcore_attach (char *args, int from_tty)
+{
+ orig_core_ops.to_attach (args, from_tty);
+ push_target (&core_ops);
+ freebsd_uthread_attaching = 1;
+}
+
+static void
+freebsd_utcore_detach (char *args, int from_tty)
+{
+ unpush_target (&core_ops);
+ orig_core_ops.to_detach (args, from_tty);
+}
+
static void
freebsd_uthread_stop (void)
{
@@ -874,12 +915,41 @@
freebsd_uthread_vec.get_thread_info = freebsd_uthread_get_thread_info;
#endif
}
+
+
+
+static void
+init_freebsd_core_ops ()
+{
+ orig_core_ops = core_ops;
+ core_ops.to_shortname = "freebsd-uthreads (corefile)";
+ core_ops.to_longname = "FreeBSD uthreads (corefile)";
+ core_ops.to_doc = "FreeBSD user threads support (for corefiles).";
+ core_ops.to_has_all_memory = 0;
+ core_ops.to_has_memory = 1;
+ core_ops.to_has_stack = 1;
+ core_ops.to_has_registers = 1;
+ core_ops.to_has_execution = 0;
+ core_ops.to_has_thread_control = tc_none;
+ core_ops.to_magic = OPS_MAGIC;
+ core_ops.to_pid_to_str = freebsd_uthread_pid_to_str;
+ core_ops.to_thread_alive = freebsd_utcore_thread_alive;
+ core_ops.to_attach = freebsd_utcore_attach;
+ core_ops.to_detach = freebsd_utcore_detach;
+ core_ops.to_stratum = core_stratum;
+ core_ops.to_find_new_threads = freebsd_uthread_find_new_threads;
+ core_ops.to_fetch_registers = freebsd_uthread_fetch_registers;
+ core_ops.to_sections = 0;
+ core_ops.to_sections_end = 0;
+}
void
_initialize_freebsd_uthread ()
{
init_freebsd_uthread_ops ();
+ init_freebsd_core_ops ();
add_target (&freebsd_uthread_ops);
+ add_target (&core_ops);
target_new_objfile_chain = target_new_objfile_hook;
target_new_objfile_hook = freebsd_uthread_new_objfile;
--Multipart_Fri__7_Feb_2003_12:42:44_+0000_082d7400--
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