From owner-freebsd-current Sat Oct 2 18: 5:33 1999 Delivered-To: freebsd-current@freebsd.org Received: from khavrinen.lcs.mit.edu (khavrinen.lcs.mit.edu [18.24.4.193]) by hub.freebsd.org (Postfix) with ESMTP id 25DA814DDB for ; Sat, 2 Oct 1999 18:05:29 -0700 (PDT) (envelope-from wollman@khavrinen.lcs.mit.edu) Received: (from wollman@localhost) by khavrinen.lcs.mit.edu (8.9.3/8.9.3) id VAA32011; Sat, 2 Oct 1999 21:05:16 -0400 (EDT) (envelope-from wollman) Date: Sat, 2 Oct 1999 21:05:16 -0400 (EDT) From: Garrett Wollman Message-Id: <199910030105.VAA32011@khavrinen.lcs.mit.edu> To: Bruce Evans Cc: current@FreeBSD.ORG Subject: Re: Now that sigcontext is gone ... In-Reply-To: References: Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG < said: > More details on the POSIX signal numbers: SIGBUS is mainly for accesses > beyond the end of mmap()ed objects. It's not clear what this means in > an address space with multiple mmap()ed objects and/or non-mmap()ed > objects. `Beyond the end of the object' refers to the situation where the mmap()ed region was specified with a longer length than the underlying object. Thus, under the following procedure: #define PGSZ sysconf(_SC_PAGE_SIZE) fd = shm_open(...); ftruncate(fd, PGSZ); p = mmap(fd, ..., 2 * PGSZ, ...); ...an access to p at offsets in the interval [PGSZ,2*PGSZ) should generate a SIGBUS. -GAWollman -- Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same wollman@lcs.mit.edu | O Siem / The fires of freedom Opinions not those of| Dance in the burning flame MIT, LCS, CRS, or NSA| - Susan Aglukark and Chad Irschick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message