RFR(XXS): 7133111: libsaproc debug print should be printed as unsigned long to fit large numbers on 64bit platform

[David Holmes]

On 5/04/2012 10:25 PM, Staffan Larsen wrote:
> Please review the following one-character fix to a printf format string. A 'z' is added to the printout of a size_t field.

Sorry I'm late to the party and this code already shipped. The z length 
modifier is not linux specific but was added as part of the C99 
standard. Is it also a gcc extension enabled by default (I don't think 
we run in C99 mode by default) ?

But z simply changes the following d/i/o/u/x/X to indicate it refers to 
a size_t - which is somewhat confusing as size_t is unsigned, so does 
%zd print a signed or unsigned representation? If signed then the bug 
still exists for really large numbers.

Note the same bug exists in the BSD version of the code.

I agree with Dan that the reference to "unsigned long" in the synopsis 
is very confusing - please change the synopsis to reflect the actual 
problem e.g: "debug print should format size_t correctly".

Thanks,
David

> Thanks,
> /Staffan
>
>
> diff --git a/agent/src/os/linux/ps_core.c b/agent/src/os/linux/ps_core.c
> --- a/agent/src/os/linux/ps_core.c
> +++ b/agent/src/os/linux/ps_core.c
> @@ -440,7 +440,7 @@
>         int j = 0;
>         print_debug("---- sorted virtual address map ----\n");
>         for (j = 0; j<  ph->core->num_maps; j++) {
> -        print_debug("base = 0x%lx\tsize = %d\n", ph->core->map_array[j]->vaddr,
> +        print_debug("base = 0x%lx\tsize = %zd\n", ph->core->map_array[j]->vaddr,
>                                            ph->core->map_array[j]->memsz);
>         }
>      }