Debugging Core Files Using HP WDB (5900-1573; WDB 6.2; January 2011)

Example 11 Debugging of a Core File Created by a Stripped Binary When the Symbol
Table is Available from Another Program
In this example, three copies of a program (program a1, program a2, and program a3
) are compiled and linked with a different order.
For example:
Program a1 is stripped.
Program a2 is an unstripped copy of program a1.
Program a3 is functionally the same as program a1. However, the code and the symbols
are in a different link order.
Using the symbol information from a3 to debug the core file generated by a1 does not
provide reliable symbol information as illustrated in the following example:
$ aCC main.c a.c b.c -o a1
$ aCC b.c main.c a.c -o a3
$ cp a1 a2
$ strip a1
$ ./a1
Abort(core dump)
$ gdb a1 core
HP gdb
... (Some output dropped)
Core was generated by `a1'.
Program terminated with signal 6, Aborted.
warning: Unable to find __dld_flags symbol in object file.
(no debugging symbols found)...(no debugging symbols found)...
(no debugging symbols found)...#0 0xc01f2740 in kill () from /usr/lib/libc.2
The backtrace of a1 does not display information about the routines, because the program
is stripped.
The symbol information of a2 can be used to analyze the backtrace from a1.
The symbol information from a3 does not provide reliable results, because the link order
is different. Unless the program a3 has a similar link order, the symbol information is
not reliable for debugging the core file created by a1. The version of the compiler and
the compiler options used can also alter the reliability of this approach.
The following example shows the backtrace for a1, a2, and a3.
(gdb) bt
#0 0xc01f2740 in kill () from /usr/lib/libc.2
#1 0xc018fc94 in raise () from /usr/lib/libc.2
#2 0xc01d00dc in abort_C () from /usr/lib/libc.2
#3 0xc01d0134 in abort () from /usr/lib/libc.2
#4 0x2498 in <unknown_procedure> () from /home/shane/test/./a1
#5 0x2430 in <unknown_procedure> () from /home/shane/test/./a1
(gdb) symbol a2
Reading symbols from a2...(no debugging symbols found)...done.
(gdb) bt
#0 0xc01f2740 in kill () from /usr/lib/libc.2
#1 0xc018fc94 in raise () from /usr/lib/libc.2
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