Date: Tue, 05 Jun 2018 05:06:24 -0700 From: Cy Schubert <Cy.Schubert@cschubert.com> To: Ganbold Tsagaankhuu <ganbold@gmail.com> Cc: Mark Johnston <markj@freebsd.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r334626 - in head: lib/libc/amd64 lib/libc/amd64/sys lib/libc/arm lib/libc/arm/sys lib/libc/i386 lib/libc/i386/sys lib/libc/mips lib/libc/mips/sys lib/libc/powerpc lib/libc/powerpc/sys ... Message-ID: <201806051206.w55C6O4K035526@slippy.cwsent.com> In-Reply-To: Message from Ganbold Tsagaankhuu <ganbold@gmail.com> of "Tue, 05 Jun 2018 15:50:12 %2B0800." <CAGtf9xNWtzDZRKOVLK37U3kru-btDbmxLjisWTfCePhqZ-M=YA@mail.gmail.com>
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In message <CAGtf9xNWtzDZRKOVLK37U3kru-btDbmxLjisWTfCePhqZ-M=YA@mail.gma il.com> , Ganbold Tsagaankhuu writes: > On Tue, Jun 5, 2018 at 3:35 AM, Mark Johnston <markj@freebsd.org> wrote: > > > Author: markj > > Date: Mon Jun 4 19:35:15 2018 > > New Revision: 334626 > > URL: https://svnweb.freebsd.org/changeset/base/334626 > > > > Log: > > Reimplement brk() and sbrk() to avoid the use of _end. > > > > Previously, libc.so would initialize its notion of the break address > > using _end, a special symbol emitted by the static linker following > > the bss section. Compatibility issues between lld and ld.bfd could > > cause the wrong definition of _end (libc.so's definition rather than > > that of the executable) to be used, breaking the brk()/sbrk() > > interface. > > > > Avoid this problem and future interoperability issues by simply not > > relying on _end. Instead, modify the break() system call to return > > the kernel's view of the current break address, and have libc > > initialize its state using an extra syscall upon the first use of the > > interface. As a side effect, this appears to fix brk()/sbrk() usage > > in executables run with rtld direct exec, since the kernel and libc.so > > no longer maintain separate views of the process' break address. > > > > > Maybe it is not really related, or I'm doing something wrong, but when I > try to run release.sh script on FreeBSD 11.0-RELEASE-p9 to build pine64 > image, it stops with error: > ... > /usr/obj/usr/src/arm64.aarch64/tmp/usr/bin/ld: error: undefined symbol: brk > >>> referenced by brk_test.c:52 (/usr/src/lib/libc/tests/sys/brk_test.c:52) > >>> brk_test.o:(atfu_brk_basic_body) > > /usr/obj/usr/src/arm64.aarch64/tmp/usr/bin/ld: error: undefined symbol: sbrk > >>> referenced by brk_test.c:55 (/usr/src/lib/libc/tests/sys/brk_test.c:55) > >>> brk_test.o:(atfu_brk_basic_body) > > /usr/obj/usr/src/arm64.aarch64/tmp/usr/bin/ld: error: undefined symbol: brk > >>> referenced by brk_test.c:59 (/usr/src/lib/libc/tests/sys/brk_test.c:59) > >>> brk_test.o:(atfu_brk_basic_body) > > /usr/obj/usr/src/arm64.aarch64/tmp/usr/bin/ld: error: undefined symbol: brk > >>> referenced by brk_test.c:65 (/usr/src/lib/libc/tests/sys/brk_test.c:65) > >>> brk_test.o:(atfu_brk_basic_body) > > /usr/obj/usr/src/arm64.aarch64/tmp/usr/bin/ld: error: undefined symbol: sbrk > >>> referenced by brk_test.c:67 (/usr/src/lib/libc/tests/sys/brk_test.c:67) > >>> brk_test.o:(atfu_brk_basic_body) > > /usr/obj/usr/src/arm64.aarch64/tmp/usr/bin/ld: error: undefined symbol: sbrk > >>> referenced by brk_test.c:82 (/usr/src/lib/libc/tests/sys/brk_test.c:82) > >>> brk_test.o:(atfu_sbrk_basic_body) > ... > > Ganbold Do a clean build or at the very least remove all libc objects and depends, the while directory in /usr/obj, and build again. -- Cheers, Cy Schubert <Cy.Schubert@cschubert.com> FreeBSD UNIX: <cy@FreeBSD.org> Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.
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