Question

I’m using the latest version of dbxtool (Solaris Studio ) on RHEL6.1.

I’m working through the tutorial example here using their example code, but when trying to run dbxtool on the core file generated, I get the following:

(dbx) cd /users/rory/Desktop/debug_tutorial
(dbx) debug /users/rory/Desktop/debug_tutorial/a.out core.a.out.10665
Reading a.out
dbx: warning: The corefile was truncated.
It should have been 1765376 bytes long (is only 483328)
Because of this, some functionality will be missing from dbx.
(See `help core')
core file header read successfully
Reading ld-linux-x86-64.so.2
Reading libstdc++.so.6
Reading libm.so.6
Reading libgcc_s.so.1
Reading libc.so.6
program terminated by signal SEGV (Segmentation fault)
dbx: core file read error: address 0x3faff579bc not available
dbx: attempt to fetch registers failed - stack corrupted

The first warning is about the core file being truncated (should have been 1765376 bytes long (is only 483328)), but I am able to generate other core files in the same directory with a larger size, so not sure why this one is being truncated?

I’ve also gone through the tutorial here on removing core size file limits, but with no luck.

Answer 1

This is a known dbx problem on RH6 (CR 7077948). The core file size is miscalculated if a data segment has a memory size larger than the file size (p_filesz) in the elf header. This problem has been identified and fixed in dbx 7.9.