Re: shlibs/1914: gdb does not notice dynamic library loads when attached to running process

["Ewa Matejska" <Ewa dot Matejska at palmsource dot com>]

The following reply was made to PR shlibs/1914; it has been noted by GNATS.

From: "Ewa Matejska" <Ewa.Matejska@palmsource.com>
To: <gdb-gnats@sources.redhat.com>
Cc:  
Subject: Re: shlibs/1914: gdb does not notice dynamic library loads when attached to running process
Date: Wed, 23 Nov 2005 18:54:17 -0800

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 Hi,
 =20
 I've noticed this problem as well.
 My environment is Ubuntu Linux.  I'm attaching a testcase and
 instructions on how to reproduce the problem.
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 This also reproduces with the CVS gdb.  Looking at the source code, I
 was able to add the following lines in infcmd.c:attach_command to partly
 correct the problem:
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 #ifdef SOLIB_CREATE_INFERIOR_HOOK
 solib_create_inferior_hook();
 #endif
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 ------------ start testcase ---------------
 1. Compile the testcase. The testcase uses dlopen to open the
 /usr/lib/libm.so library.  Modify the testcase if you want it to open
 something else.
     gcc -O0 -g3 -Wall -c -fmessage-length=3D0 -oprogram.o ./program.c
     gcc -odummyprogram ./program.o -ldl
 This results in a testcase named "dummyprogram".
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 2. Run this program.
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 3. Check the pid and create a gdb session attached to that pid.
     gdb ./dummyprogram pid
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 4.  Here is the gdb session which shows the problem:
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 (gdb) info shared
     From            To                Syms Read        Shared Object
 Library
     0xb7fdce80    0xb7fddc70    Yes
 /lib/tls/i686/libdl.so.2
     0xb7ec46e0   0xb7fb44b8    Yes
 /lib/tls/i686/libc.so.6
     0xb7febc00    0xb7ffc54f      Yes                /lib/ld-linux.so.2
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 (gdb) show auto-solib-add
 Autoloading of shared library symbols is on.
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 (gdb) b program.c:7
 Breakpoint 1 at 0x8048413: file ./program.c, line 7.
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 (gdb) b program.c:9
 Breakpoint 2 at 0x8048421: file ./program.c, line 9.
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 (gdb c)
 Continuing
 Breakpoint 1, main() at ./program.c:7
 7 sleep(2);
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 (gdb) set bla=3D0
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 (gdb) c
 Continuing.
 Breakpoint 2, main() at ./program.c:9
 9 dlopen("/usr/lib/libm.so", RTLD_NOW);
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 (gdb) n
 10 return 0;
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 (gdb) info shared
     From            To                Syms Read        Shared Object
 Library
     0xb7fdce80    0xb7fddc70    Yes
 /lib/tls/i686/libdl.so.2
     0xb7ec46e0   0xb7fb44b8    Yes
 /lib/tls/i686/libc.so.6
     0xb7febc00    0xb7ffc54f      Yes                 /lib/ld-linux.so.2
     0xb7290620   0xb7ea6fd0    No                  /usr/lib/libm.so
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 This shows that the symbols were not loaded for libm.so.
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 ------------End testcase ---------------------
 =20
 Thanks,
 Ewa.
 PalmSource.
 
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