peeping tom

as usual, i have some interesting stuff that you geeks might be interested in reading, if you haven't checked them out yet:

• Smack the Stack. since kernel 2.6.12, stack protection has been added to the linux kernel by default. this patch (va randomization) randomized the stack within 8Mb, and applies to ELF binaries. however, there are ways to circumvent it, by means of some advanced stack overflow methods. a few methods is presented: stack juggling, ret2pop, ret2eax, ret2esp, stack and stethoscope. let me suggest this: grsec.


• A comparison of Linux, Solaris and FreeBSD Kernels. the basic stuff are explained in general: memory management, scheduling, file system, etc.


• Performance Tuning With GCC, Part 1. this part basically explains most of the important stuff in man gcc that is performance and optimization-related, but in more details.


• Performance Tuning with GCC, Part 2. this part deals with analyzing performance problems using gprof, GNU profiler, valgrind, and oprofile. if you're a gentoo geek, this is a must read.

while going to gym has nothing to do with gcc optimization, i can't help but to note the similarities with a well-planned workout routine and optimization. -Os or -O9 or -fomg-super-optimialization may not work in all software classes. similarly, carrying so much weight (e.g. 50kg on the benchpress with 10 reps x 5 sets will gain you less mass than carrying 40kg x 12 reps x 5 sets). what i'm trying to say is - experiment with the various optimization methods and flags, and what may work for your system may not work for others. however, some rule of thumbs do apply, such as combining many different optimization flags can cause more harm than good. similarly, doing incline dumbbell press without focus on the chest muscles (for example, squeezing the muscles as you lift the dumbells up) will give slower results.

and oh, either run your security appliance on openbsd or grsec-ed your linux box.

listening to: ben folds five - kate