This is the mail archive of the elfutils-devel@sourceware.org mailing list for the elfutils project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH 1/3] libdw: Make srclines use a stable sort


BTW, I want to point out this change in compare_lines:

> -  return (*p1)->addr - (*p2)->addr;
[...]
> +  if (line1->addr != line2->addr)
> +    return (line1->addr < line2->addr) ? -1 : 1;

Since addr is 64-bit unsigned, and comparison functions return int, it
is possible for the difference to be so large that it wraps around.  You
only need INT_MAX or more -- which probably doesn't happen often in ELF
files, but it's plausible.

It might be worth auditing other qsort/tsearch comparison functions for
similar wrapping possibilities.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]