| Message ID | 20171215150659.1811-2-marcandre.lureau@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | Various build-sys and ASAN related fixes | expand |
Hi Marc-André, On 12/15/2017 12:06 PM, Marc-André Lureau wrote: > When linking qemu-ga under some configuration (when gthread-2.0.pc > doesn't have -pthread, as happening atm with meson build), you may > have this linking issue: > > /usr/bin/ld: libqemuutil.a(qemu-thread-posix.o): undefined reference to symbol 'pthread_setname_np@@GLIBC_2.12' > /usr/lib64/libpthread.so.0: error adding symbols: DSO missing from command line > > Make sure qemu-ga links with the pthread library, by adding correct > flags to libs_qga. > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> > --- > configure | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/configure b/configure > index 0c6e7572db..2b8c71f522 100755 > --- a/configure > +++ b/configure > @@ -3436,6 +3436,7 @@ else > done > if test "$found" = "no"; then > LIBS="$pthread_lib $LIBS" > + libs_qga="$pthread_lib $libs_qga" > fi > PTHREAD_LIB="$pthread_lib" > break Hmm why not add it later, around line 4270: if compile_prog "" "" ; then : # we need pthread for static linking. use previous pthread test result elif compile_prog "" "$pthread_lib -lrt" ; then LIBS="$LIBS -lrt" libs_qga="$libs_qga -lrt" # <-- here fi
On 15 December 2017 at 18:21, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: > Hi Marc-André, > > On 12/15/2017 12:06 PM, Marc-André Lureau wrote: >> When linking qemu-ga under some configuration (when gthread-2.0.pc >> doesn't have -pthread, as happening atm with meson build), you may >> have this linking issue: >> >> /usr/bin/ld: libqemuutil.a(qemu-thread-posix.o): undefined reference to symbol 'pthread_setname_np@@GLIBC_2.12' >> /usr/lib64/libpthread.so.0: error adding symbols: DSO missing from command line >> >> Make sure qemu-ga links with the pthread library, by adding correct >> flags to libs_qga. This commit message misled me temporarily, because it suggests that the problem is with the gthread-2.0.pc pkg-config file. But this is really a QEMU bug, because it's QEMU code that's using pthread functions, and so we must explicitly link against pthreads. The bug was just masked by the fact that often some pkg-config or another for one of our dependencies will add -pthread to the link line anyway. >> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> >> --- >> configure | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/configure b/configure >> index 0c6e7572db..2b8c71f522 100755 >> --- a/configure >> +++ b/configure >> @@ -3436,6 +3436,7 @@ else >> done >> if test "$found" = "no"; then >> LIBS="$pthread_lib $LIBS" >> + libs_qga="$pthread_lib $libs_qga" >> fi >> PTHREAD_LIB="$pthread_lib" >> break Reviewed-by: Peter Maydell <peter.maydell@linaro.org> > Hmm why not add it later, around line 4270: > > if compile_prog "" "" ; then > : > # we need pthread for static linking. use previous pthread test result > elif compile_prog "" "$pthread_lib -lrt" ; then > LIBS="$LIBS -lrt" > libs_qga="$libs_qga -lrt" # <-- here > fi Because that's a different test, which is checking whether we need to link against librt. We might need to link against pthread even if we don't need to link against librt. thanks -- PMM
Hi On Fri, Dec 15, 2017 at 7:21 PM, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: > Hi Marc-André, > > On 12/15/2017 12:06 PM, Marc-André Lureau wrote: >> When linking qemu-ga under some configuration (when gthread-2.0.pc >> doesn't have -pthread, as happening atm with meson build), you may >> have this linking issue: >> >> /usr/bin/ld: libqemuutil.a(qemu-thread-posix.o): undefined reference to symbol 'pthread_setname_np@@GLIBC_2.12' >> /usr/lib64/libpthread.so.0: error adding symbols: DSO missing from command line >> >> Make sure qemu-ga links with the pthread library, by adding correct >> flags to libs_qga. >> >> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> >> --- >> configure | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/configure b/configure >> index 0c6e7572db..2b8c71f522 100755 >> --- a/configure >> +++ b/configure >> @@ -3436,6 +3436,7 @@ else >> done >> if test "$found" = "no"; then >> LIBS="$pthread_lib $LIBS" >> + libs_qga="$pthread_lib $libs_qga" >> fi >> PTHREAD_LIB="$pthread_lib" >> break > > Hmm why not add it later, around line 4270: This is check place for librt usage, better to keep it around pthread checks. > > if compile_prog "" "" ; then > : > # we need pthread for static linking. use previous pthread test result > elif compile_prog "" "$pthread_lib -lrt" ; then > LIBS="$LIBS -lrt" > libs_qga="$libs_qga -lrt" # <-- here > fi >
diff --git a/configure b/configure index 0c6e7572db..2b8c71f522 100755 --- a/configure +++ b/configure @@ -3436,6 +3436,7 @@ else done if test "$found" = "no"; then LIBS="$pthread_lib $LIBS" + libs_qga="$pthread_lib $libs_qga" fi PTHREAD_LIB="$pthread_lib" break
When linking qemu-ga under some configuration (when gthread-2.0.pc doesn't have -pthread, as happening atm with meson build), you may have this linking issue: /usr/bin/ld: libqemuutil.a(qemu-thread-posix.o): undefined reference to symbol 'pthread_setname_np@@GLIBC_2.12' /usr/lib64/libpthread.so.0: error adding symbols: DSO missing from command line Make sure qemu-ga links with the pthread library, by adding correct flags to libs_qga. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> --- configure | 1 + 1 file changed, 1 insertion(+)