Date: Sat, 2 Oct 1999 21:05:16 -0400 (EDT) From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu> To: Bruce Evans <bde@zeta.org.au> Cc: current@FreeBSD.ORG Subject: Re: Now that sigcontext is gone ... Message-ID: <199910030105.VAA32011@khavrinen.lcs.mit.edu> In-Reply-To: <Pine.BSF.4.10.9910030928230.4614-100000@alphplex.bde.org> References: <XFMail.991002122051.jdp@polstra.com> <Pine.BSF.4.10.9910030928230.4614-100000@alphplex.bde.org>
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<<On Sun, 3 Oct 1999 09:42:45 +1000 (EST), Bruce Evans <bde@zeta.org.au> 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
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