Re: libsigsegv?

[Dmitry Antipov]

On 09/11/2014 07:08 PM, Eli Zaretskii wrote:

> Apropos stack overflow protection: why not use libsigsegv if it is
> available?  It is capable of doing what we want (AFAICT), and supports
> more platforms, including MS-Windows.

1. Stefan's mood gets worse after each new library dependency.

2. Basically libsigsegv uses the following heuristics to distinguish between
   stack overflow and other kinds of SIGSEGVs:
   a) If the fault address is near the stack pointer, it's a stack overflow.
   b) If the fault address is near and beyond the bottom of the stack's virtual
      memory area, it's a stack overflow.
   c) If the stack pointer is near the bottom of the stack's virtual memory 
area,
      it's a stack overflow.

   Currently we have only b), and this is the only thing which can be 
implemented
   staying in POSIX interfaces and without architecture-dependent tricks. a) may
   be implemented in a small forest of #ifdefs, and it doesn't worth using an
   extra library. c) is the most controversial - for example, on GNU/Linux it 
works
   by opening and reading /proc/self/maps.  Do you really want to open and read 
file
   on SIGSEGV?  I do not.

Dmitry