Date: Wed, 20 Aug 2014 18:13:10 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Roger Pau Monn?? <royger@FreeBSD.org> 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: <20140820151310.GB2737@kib.kiev.ua> In-Reply-To: <53F4B381.5010205@FreeBSD.org> References: <201404270528.s3R5SEIm054377@svn.freebsd.org> <53F4B381.5010205@FreeBSD.org>
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[-- Attachment #1 --] 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 ? > > --- > #include <signal.h> > #include <string.h> > #include <assert.h> > > int main(int argn, char **argv) > { > struct sigaction new, old; > int rc; > > memset(&new, 0, sizeof(new)); > memset(&old, 0, sizeof(old)); > > sigemptyset(&new.sa_mask); > new.sa_handler = SIG_DFL; > new.sa_flags = 0; > > rc = sigaction(SIGCHLD, &new, &old); > assert(rc == 0); > assert((old.sa_handler == SIG_DFL || old.sa_handler == SIG_IGN) && > !(old.sa_flags & SA_SIGINFO)); > > return (0); > } > [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJT9LsGAAoJEJDCuSvBvK1BVvoP/2wZgcRcmIxcS2rpxDyYmeMO 4y8aNjJcWez9OFZTwRQpBMXnBgbzKT0ohQWQItGfcPp9WaRp4Ea/+FEQEaU1c5is 3R8sHIFbKPLkeWotec0Nl56QjDOOn2E4v+9MPCKz0eRR68seNDfViZxpcSSTXpf+ Y/hNsQl+rKMDLgOggNRe2CPa5LDHn9vgm8OOoQVSnvwPiOtp0KTvkMdU1PjUydfe 0rmx5kKvoMWE3BTDKAFbRDmTPHrC1MHxMwEJwIudbXdsTHJBVBvtDgwWkSkmPUPT I2NUD5AmZ8sQwVD1r9THFSpm/ToJ8I38CjKe8Y0sElb4fg6c8wJ5tH+4gcDAyBRz cTilZJj/UYqpt9DDJZM+F384UehWr9pOqQxwW4Vdpj/R1Yweyi5Oj350z9UBXXuP QIOAyxWQh2Mu3Xj6yRfld1swSowtEbpimhNrzLQadbyhRsnqwQcxXsXiawgCPl/r ktwZ6eKK4d97n6f35aE976+6M13bxZydU2WIVhV714Ok0ove2A4jGBxvPwym3Ncl gLvpbrxTBwcrm3MZuTfuAnkCUoDREc83bDwZ6ImSDoQxk60rhpGJIYTTg/HjxJw2 lHJn/th5eDjy7vVl7x8XKmqyzCSWwz4M9JSbaOiAuZcB/4Z7D1U94sJaGzFzL9Lh 0t4ggzLYJaKyIs6i1Ga9 =KKeI -----END PGP SIGNATURE-----help
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