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From: Daniel_Roedding@fiction.ms.sub.org
Newsgroups: comp.unix.wizards
Subject: panic() / firsttime
Message-ID: <299574@fiction>
Date: 27 Aug 90 22:15:14 GMT
Lines: 51
X-Attributes: type 2, from 100, acclv 0, expires

jbm@eos.UUCP (Jeffrey Mulligan) writes:

dave@tis.com (David I. Dalva) writes:

> >The code goes something like this:

> >	panic(s)
> >		char *s;
> >	{
> >		printf("%s\n", s);
> >		if (firsttime) {
> >			firsttime = FALSE;
> >			sync();
> >		}
> >		halt();
> >	}

> It would seem that the use of the flag "firsttime" is to prevent
> multiple or recursive calls to sunc(); if this is happening, then
> perhaps whatever is causing the panic is also scribbling over
> firsttime.  Maybe you could try moving it to another part of the
> address space and see what happens.

Probably it's sufficient to assign a "magic" value to "firsttime".
A manipulation could be detected much easier:

panic(s)
char *s;
{
   printf("%s\n",s);
   switch (firsttime) {
      case FT_FIRST:
         firsttime=FT_SECOND;
         sync();
      case FT_SECOND:
         halt();
      default:
         printf("Argh -- who manipulated my vars????\n");
         halt();
   }
}


Daniel

---
Daniel Roedding                                       #include <disclaimer.h>
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