Date: Wed, 20 Aug 2014 17:19:55 +0200 From: =?ISO-8859-1?Q?Roger_Pau_Monn=E9?= <royger@FreeBSD.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r265003 - head/secure/usr.sbin/sshd Message-ID: <53F4BC9B.3090405@FreeBSD.org> In-Reply-To: <20140820151310.GB2737@kib.kiev.ua> References: <201404270528.s3R5SEIm054377@svn.freebsd.org> <53F4B381.5010205@FreeBSD.org> <20140820151310.GB2737@kib.kiev.ua>
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On 20/08/14 17:13, Konstantin Belousov wrote: > On Wed, Aug 20, 2014 at 04:41:05PM +0200, Roger Pau Monn?? wrote: >> On 27/04/14 07:28, Konstantin Belousov wrote: >>> Author: kib >>> Date: Sun Apr 27 05:28:14 2014 >>> New Revision: 265003 >>> URL: http://svnweb.freebsd.org/changeset/base/265003 >>> >>> Log: >>> Fix order of libthr and libc in the global dso list for sshd, by >>> explicitely linking main binary with -lpthread. Before, libthr >>> appeared in the list due to dependency of one of the kerberos libs. >>> Due to the change in ld(1) behaviour of not copying NEEDED entries >>> from direct dependencies into the link results, the order becomes >>> reversed. >>> >>> The libthr must appear before libc to properly interpose libc symbols >>> and provide working rtld locks implementation. The symptom was sshd >>> hanging on rtld bind lock during nested symbol binding from a signal >>> handler. >>> >>> Approved by: des (openssh maintainer) >>> Sponsored by: The FreeBSD Foundation >>> MFC after: 1 week >>> >>> Modified: >>> head/secure/usr.sbin/sshd/Makefile >>> >>> Modified: head/secure/usr.sbin/sshd/Makefile >>> ============================================================================== >>> --- head/secure/usr.sbin/sshd/Makefile Sun Apr 27 05:19:01 2014 (r265002) >>> +++ head/secure/usr.sbin/sshd/Makefile Sun Apr 27 05:28:14 2014 (r265003) >>> @@ -57,6 +57,16 @@ CFLAGS+= -DNONE_CIPHER_ENABLED >>> DPADD+= ${LIBCRYPT} ${LIBCRYPTO} ${LIBZ} >>> LDADD+= -lcrypt -lcrypto -lz >>> >>> +# Fix the order of NEEDED entries for libthr and libc. The libthr >>> +# needs to interpose libc symbols, leaving the libthr loading as >>> +# dependency of krb causes reversed order and broken interposing. Put >>> +# the threading library last on the linker command line, just before >>> +# the -lc added by a compiler driver. >>> +.if ${MK_KERBEROS_SUPPORT} != "no" >>> +DPADD+= ${LIBPTHREAD} >>> +LDADD+= -lpthread >>> +.endif >>> + >>> .if defined(LOCALBASE) >>> CFLAGS+= -DXAUTH_PATH=\"${LOCALBASE}/bin/xauth\" >>> .endif >> >> Hello, >> >> This change makes the following simple test program fail on the second >> assert. The problem is that sa_handler == SIG_DFL, and sa_flags == >> SA_SIGINFO, which according to the sigaction(9) man page is not >> possible. With this change reverted the test is successful. > I do not quite follow. > > What are the relations between sshd and your test program ? > Should the test be run somehow specially ? No, and frankly that's what I don't understand. I compile this simple test with `cc -o test test.c`. It fails with this commit applied, and succeeds without it. Roger.
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