PROJECT DOSSIER // [FTRACE]VIEW SOURCEBACK TO PROJECTS →

01 // PROJECT AT A GLANCE

FTRACE

C

Reconstituting, at runtime, a program's function call tree.

The logical sequel to strace, but a notch harder: instead of following the requests made to the system, you follow the calls the program makes to itself. The system offers no help for that — you have to decode processor instructions on the fly and recover the names from the executable's symbol table.

A tracer combining step-by-step ptrace with ELF symbol table reading: it prints the entry and exit of every function in the traced binary, the system calls with their arguments and return, and the signals received.

PRIMARYC
DELIVERYTEAM RECORD
VERIFICATIONCriterion
SOURCEINSPECTOR READY
MEDIA ATTACHMENTS (Images, Photos, Videos)

02 // PROJECT SIGNALS

DATE:
2019
PRIMARY LANG:
C
GRADE:
A
DURATION:
2 weeks
SECONDARY:
—
STACK:
Makefile / gcc

03 // KEY OUTCOMES

  • Function entries detected by comparing rip against the ELF symbol table, step by step
  • Returns and system calls recognised by reading opcodes directly
  • A unified trace: internal functions, system calls and received signals

BEYOND THE BRIEF

  • Two Criterion test files, one on the nominal case, the other on errors

04 // SOURCE TREE

READING SOURCE…