NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part1/859

Internet Message Format | 1996-08-05 | 1.7 KB

Path: mail2news.demon.co.uk!genesis.demon.co.uk
From: Lawrence Kirby <[e-mail]>
Newsgroups: comp.unix.questions,comp.lang.c,comp.unix.programming
Subject: Re: SIGBUS - What are the possible causes?
Date: Tue, 09 Jan 96 18:58:17 GMT
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Message-ID: <[e-mail]>
References: <4ct4es$[e-mail]>
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In article <4ct4es$[e-mail]> [e-mail] "McGuire" writes:

>Hello all,
>
>I am trying to compile a program under gcc 2.7.0 that works under the
>native HP-UX 9.05 cc.  In one routine I get a SIGBUS error.  When I
>ignore the SIGBUS error, I get a segmentation violation.  When I add
>some code to test what might be happening, the location at which the
>error occurs appears to change (I am using gdb under xemacs).  Does
>anyone have any ideas as to what the possible causes of such an error
>might be.

99% of the time you're doing something screwy with pointers. e.g.

1. Using pointer arithmetic to generate pointers outside the bounds of
   objects

2. Dereferencing an illegal pointer e.g. NULL, uninitialised, 1 past the
   end of an array, pointer to an object that has been freed, or one
   created by an illegal cast from an integer or another pointer type.

3. Passing an illegal pointer to free i.e. one not generated by
   malloc/calloc/realloc or which has already been freed.

--
-----------------------------------------
Lawrence Kirby | [e-mail]
Wilts, England | [e-mail]
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