Date: Sat, 17 Dec 2011 10:33:55 +0200 From: Kostik Belousov <kostikbel@gmail.com> To: Dimitry Andric <dim@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r228616 - head/usr.bin/tar Message-ID: <20111217083355.GZ50300@deviant.kiev.zoral.com.ua> In-Reply-To: <201112170136.pBH1apEH036884@svn.freebsd.org> References: <201112170136.pBH1apEH036884@svn.freebsd.org>
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[-- Attachment #1 --] On Sat, Dec 17, 2011 at 01:36:51AM +0000, Dimitry Andric wrote: > Author: dim > Date: Sat Dec 17 01:36:50 2011 > New Revision: 228616 > URL: http://svn.freebsd.org/changeset/base/228616 > > Log: > In usr.bin/tar/tree.c, if you really want to poke to NULL, you must use > volatile, otherwise the indirection will not be emitted. > > MFC after: 1 week > > Modified: > head/usr.bin/tar/tree.c > > Modified: head/usr.bin/tar/tree.c > ============================================================================== > --- head/usr.bin/tar/tree.c Sat Dec 17 01:29:46 2011 (r228615) > +++ head/usr.bin/tar/tree.c Sat Dec 17 01:36:50 2011 (r228616) > @@ -315,7 +315,7 @@ tree_next(struct tree *t) > const char *msg = "Unable to continue traversing" > " directory hierarchy after a fatal error."; > write(2, msg, strlen(msg)); > - *(int *)0 = 1; /* Deliberate SEGV; NULL pointer dereference. */ > + *(volatile int *)0 = 1; /* Deliberate SEGV; NULL pointer dereference. */ > exit(1); /* In case the SEGV didn't work. */ > } > Why this hack is used instead of abort(3) or abort2(2) ? [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) iEYEARECAAYFAk7sU/MACgkQC3+MBN1Mb4hqWwCfV1fv1gU4yVIFa/joVJoIAph3 HWgAmwWe73QJ40q9P+POHVzGMZTtYK0E =XdaY -----END PGP SIGNATURE-----help
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