Technical data

4. Packages
717 rrd_file->pos += count;
718 return count; /* mimmic write() semantics */
719 #else
720 ssize_t _sz = write(rrd_simple_file->fd, buf, count);
(gdb) list 700
695 * rrd_file->pos of rrd_simple_file->fd.
696 * Returns the number of bytes written or <0 on error. */
697
698 ssize_t rrd_write(
699 rrd_file_t *rrd_file,
700 const void *buf,
701 size_t count)
702 {
703 rrd_simple_file_t *rrd_simple_file = (rrd_simple_file_t *)rrd_file->
pvt;
704 #ifdef HAVE_MMAP
(gdb) print *(rrd_simple_file_t *)rrd_file->pvt
$2 = {fd = 9, file_start = 0xa67d0000 <Address 0xa67d0000 out of bounds>,
mm_prot = 3, mm_flags = 1}
After some “digging”, you will see that an invalid pointer is contained in the
rrd_simple_file_t object (“Address ... out of bounds”). In the further process of debugging,
it became clear that a failed posix_fallocate-call was the culprit for the crash.
It is important to pass all paths fully qualified (/project/...) and to use no “shortcuts”
(i.e. in ˜/...). If you don’t obey this it may happen that gdb will not find the debug
informations for the application and/or for the libraries in use. Due to space reasons debug
informations are not contained directly in the program to be investigated but are saved in
separate files in the directoy ˜/.fbr/fbr-<branch>-<arch>/buildroot/output/debug/.
4.24.5. Informations On The FBR
Displaying Help
Use the command fbr-make help to see what fbr-make can do for you.
Displaying Program Informations
By using the command fbr-make show-versions you can review all FBR packages provided
with version number:
$ fbr-make show-versions
Configured packages
acpid 2.0.20
actctrl 3.25+dfsg1
add-days undefined
[...]
Display Of Dependencies On Libraries
With fbr-make links-against <soname> all files in ˜/.fbr/fbr-<branch>-<arch>/buildroot
/output/target linked to a library named soname can be shown. If for example all programs
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