[Valgrind-users] Do you already have a --tidoffset parameter?

[Peter H S. <smi...@us...>]

When I run a program under valgrind, pthread_self() will
return a number between 1 and 50.  This doesn't catch
some latent errors.  Consider this simplification of
some bone-headed trace code:

#define PENNY_WISE 5
char header[PENNY_WISE];
sprintf(header, "%d: ", pthread_self());
fprintf(stderr, "%s%s\n", header, message);

There is a latent buffer overrun here that won't be tripped
under Valgrind because thread ids are always small.
I'd like to be able to set the base thread id to something
like 0x800000000 or 0xFFFF0000 and test to be sure
this buffer nonsense is not a problem.

I suppose it's harder, but it would also be nice to be able
to put a "translation layer" between getpid() and kill(), etc
so that you could force pids to be large too.  At least make
getpid() return a configurable value like 0x80000000 or
0xF0000000, and have kill() turn it back to the right value
before passing it on.  Ideally translate any returned pid to
have some minimum value, and translate the returned pids
to real pids on the way out.  This wouldn't be perfect but
would be useful in stoopid programs.

I suppose I should get over "code approach anxiety" and
add it myself, but I'm too busy finding bone-headed buffer
overflows to put it in right now...

Peter H. Smith
Advisory Software Engineer
xSeries Systems Management
IBM Server Group
Phone (919) 543-6140 (T/L 441-6140)
email: smi...@us...