On 02/03/18 13:40, Wei Liu wrote: > On Fri, Mar 02, 2018 at 12:29:31PM +0000, Wei Liu wrote: >> On Mon, Feb 26, 2018 at 09:53:38AM -0700, Jim Fehlig wrote: >>> On 02/26/2018 01:46 AM, Juergen Gross wrote: >>>> When creating a pthread in xs_watch() try to get the minimal needed >>>> size of the thread from glibc instead of using a constant. This avoids >>>> problems when the library is used in programs with large per-thread >>>> memory. >>>> >>>> Use dlsym() to get the pointer to __pthread_get_minstack() in order to >>>> avoid linkage problems and fall back to the current constant size if >>>> not found. >>>> >>>> Signed-off-by: Juergen Gross <jgr...@suse.com> >>>> --- >>>> V2: >>>> - use _GNU_SOURCE (Wei Liu) >>>> - call __pthread_get_minstack() with parameter >>>> - add -ldl to correct make flags >>>> - ensure to not using smaller stack size than today >>>> --- >>>> tools/xenstore/Makefile | 4 ++++ >>>> tools/xenstore/xs.c | 21 ++++++++++++++++++++- >>>> 2 files changed, 24 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/tools/xenstore/Makefile b/tools/xenstore/Makefile >>>> index 2b99d2bc1b..0831be0b6f 100644 >>>> --- a/tools/xenstore/Makefile >>>> +++ b/tools/xenstore/Makefile >>>> @@ -100,6 +100,10 @@ libxenstore.so.$(MAJOR): >>>> libxenstore.so.$(MAJOR).$(MINOR) >>>> ln -sf $< $@ >>>> xs.opic: CFLAGS += -DUSE_PTHREAD >>>> +ifeq ($(CONFIG_Linux),y) >>>> +xs.opic: CFLAGS += -DUSE_DLSYM >>>> +libxenstore.so.$(MAJOR).$(MINOR): LDFLAGS += -ldl >>>> +endif >>> >>> Dropping this patch in one of my automated builds caused a libxenstore link >>> failure >>> >>> [ 99s] gcc -lsystemd -ldl -pthread -Wl,-soname -Wl,libxenstore.so.3.0 >>> -shared -o libxenstore.so.3.0.3 xs.opic xs_lib.opic >>> /home/abuild/rpmbuild/BUILD/xen-4.10.0-testing/tools/xenstore/../../tools/libs/toolcore/libxentoolcore.so >>> >>> [ 99s] >>> /home/abuild/rpmbuild/BUILD/xen-4.10.0-testing/tools/xenstore/../../tools/xenstore/libxenstore.so: >>> undefined reference to `dlsym' >>> >>> I hacked around it by appending '-ldl' to the end of the subsequent >>> libxenstore.so rule. >> >> Hmm... Maybe I'm a bit dense today. I know the position of -l matters >> but I don't quite understand how placing -pthread before xs.opic works >> but -ldl doesn't. xs.c uses both after all. > > I'm indeed very dense -- -pthread is a special option that sets the > proper flags for linking pthread library for both the preprocessor and > linker. > > But still, Juergen must have tested the change, so I wonder why it > doesn't work in your setup. What is your build environment? Gcc version?
And why is "-lsystemd" working correctly? I have tested with gcc 4.8.5, binutils 2.25.0 Juergen _______________________________________________ Xen-devel mailing list Xenfirstname.lastname@example.org https://lists.xenproject.org/mailman/listinfo/xen-devel