Can't see the function name and line numbers.

WuBingzheng / libleak

detect memory leak by LD_PRELOAD, without changing the target program

249 stars 52 forks source link

Can't see the function name and line numbers. #5

Closed kownse closed 5 years ago

kownse commented 5 years ago

callstack[1] expires. count=1 size=32/32 alloc=1 free=0 /media/kownse/OS/code/git/libleak/libleak.so(malloc+0x25) [0x7fe382456195] /usr/lib/x86_64-linux-gnu/libstdc++.so.6(_Znwm+0x18) [0x7fe38215e258] ./philo(+0x2a4e) [0x55e3a0623a4e] ./philo(+0x1e98) [0x55e3a0622e98] ./philo(+0x1883) [0x55e3a0622883] ./philo(+0x131a) [0x55e3a062231a]

Please print detail log just like memleax does.

WuBingzheng commented 5 years ago

First, make sure -g is used in compile.

memleax has to parse the symbols itself, while libleak just uses backtrace_symbols(2) because it's much simpler. backtrace_symbols(2) indeed miss some (not all) function names and line numbers, and I do not know the reason. Anyone can tell why?

You may use readelf -s philo to parse the symbol by address yourself :)

ukolovda commented 5 years ago

I got more information (function name and offset) with gcc -rdynamic option.

WuBingzheng commented 5 years ago

It seems to be the right answer. Thanks

   -rdynamic
       Pass the flag -export-dynamic to the ELF linker, on targets
       that support it. This instructs the linker to add all
       symbols, not only used ones, to the dynamic symbol table.
       This option is needed for some uses of "dlopen" or to allow
       obtaining backtraces from within a program.