GDB cannot handle backtracing on executables generated by the TI C6x compiler. When running the bt command this is the frame information that is shown 

Program received signal SIGTRAP, Trace/breakpoint trap.
0x008105e6 in $C$L4 () at ../main.c:54
54      ../main.c: No such file or directory.
(gdb) bt
#0  0x008105e6 in $C$L4 () at ../main.c:54
PC not saved

If the command "info frame" is run, sometimes this is the output - 
(gdb) info frame
Stack level 0, frame at 0x81b4b8:
 PC = 0x8105e6 in myTask (../main.c:54); saved PC = <not saved>
 called by frame at
frame.c:472: internal-error: get_frame_id: Assertion `fi->this_id.p' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)

I have included a test executable.