Hello, On Sat, 15 Jul 2017 14:44:21 +0200, Denys Vlasenko wrote:
> Can you investigate this further? > LIBBUSYBOX build results in entire busybox code being put into a library. > > nm -D libbusybox.so.1.28.0.git > > shows that there are only defined entry points to each applet's main(): > > 0007b159 T bunzip2_main > 0007c8db T bzip2_main > 000677bb T cal_main > 0008e08e T cat_main > > (so, at max less than 350 entry points), and references to libc functions: > > U asprintf > U atof > U atoi > > No internal libbb functions or variables are exposed. > > I don't understand the error messages you are seeing. bb_errno should > have hidden visibility, > meaning that it is an internal (to libbusybox.so) label, and all > references to it > should be resolved without any shared linker magic. .LCn labels are > similar, they are > referring to text strings (messages and such). > > What is going on? Why your linker has relocations between individual > .o files which go > to the same library? I'm not really sure what's going on. But the problem can very easily be reproduced: $ git clone git://git.buildroot.org/buildroot $ cd buildroot/ $ cat > .config <<EOF BR2_sparc=y BR2_TOOLCHAIN_EXTERNAL=y BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.org/toolchains/tarballs/br-sparc-uclibc-2017.05-1078-g95b1dae.tar.bz2"; BR2_TOOLCHAIN_EXTERNAL_GCC_6=y BR2_TOOLCHAIN_EXTERNAL_HEADERS_4_1=y BR2_TOOLCHAIN_EXTERNAL_LOCALE=y # BR2_TOOLCHAIN_EXTERNAL_HAS_THREADS_DEBUG is not set BR2_TOOLCHAIN_EXTERNAL_CXX=y BR2_INIT_NONE=y BR2_SYSTEM_BIN_SH_NONE=y BR2_PACKAGE_BUSYBOX_INDIVIDUAL_BINARIES=y # BR2_TARGET_ROOTFS_TAR is not set EOF $ make olddefconfig $ make It builds only Busybox, so it's very quick to reach the build failure. This time, I got: libbb/lib.a(appletlib.o): In function `find_applet_by_name': appletlib.c:(.text.find_applet_by_name+0x14): relocation truncated to fit: R_SPARC_GOT13 against symbol `applet_nameofs' defined in .rodata.applet_nameofs section in libbb/lib.a(appletlib.o) appletlib.c:(.text.find_applet_by_name+0x18): relocation truncated to fit: R_SPARC_GOT13 against symbol `applet_names' defined in .rodata.applet_names section in libbb/lib.a(appletlib.o) libbb/lib.a(appletlib.o): In function `bb_show_usage': appletlib.c:(.text.bb_show_usage+0x10): relocation truncated to fit: R_SPARC_GOT13 against symbol `applet_name' defined in COMMON section in libbb/lib.a(appletlib.o) appletlib.c:(.text.bb_show_usage+0x54): relocation truncated to fit: R_SPARC_GOT13 against symbol `bb_banner' defined in .rodata.bb_banner section in libbb/lib.a(messages.o) libbb/lib.a(appletlib.o): In function `lbb_prepare': appletlib.c:(.text.lbb_prepare+0x18): relocation truncated to fit: R_SPARC_GOT13 against symbol `bb_errno' defined in COMMON section in libbb/lib.a(ptr_to_globals.o) appletlib.c:(.text.lbb_prepare+0x20): relocation truncated to fit: R_SPARC_GOT13 against symbol `applet_name' defined in COMMON section in libbb/lib.a(appletlib.o) libbb/lib.a(appletlib.o): In function `run_applet_no_and_exit': appletlib.c:(.text.run_applet_no_and_exit+0x28): relocation truncated to fit: R_SPARC_GOT13 against symbol `xfunc_error_retval' defined in .data.xfunc_error_retval section in libbb/lib.a(default_error_retval.o) appletlib.c:(.text.run_applet_no_and_exit+0x38): relocation truncated to fit: R_SPARC_GOT13 against symbol `applet_name' defined in COMMON section in libbb/lib.a(appletlib.o) appletlib.c:(.text.run_applet_no_and_exit+0xb0): relocation truncated to fit: R_SPARC_GOT13 against symbol `applet_main' defined in .data.rel.ro.applet_main section in libbb/lib.a(appletlib.o) appletlib.c:(.text.run_applet_no_and_exit+0xcc): relocation truncated to fit: R_SPARC_GOT13 against symbol `applet_suid' defined in .rodata.applet_suid section in libbb/lib.a(appletlib.o) appletlib.c:(.text.run_applet_no_and_exit+0x11c): additional relocation overflows omitted from the output collect2: error: ld returned 1 exit status When I build with my patches (the build is successful), and then look at libbbusybox.so with readelf, the .got section is indeed very small, much smaller than the 8 KB limit detailed in gcc's documentation about -fpic vs. -fPIC: $ ./output/host/usr/bin/sparc-linux-readelf -a output/target/lib/libbusybox.so.1.26.2 | grep "\.got" [17] .got PROGBITS 000dc000 0cc000 00021c 04 WA 0 0 4 So the size is only 0x21c. Any idea on how to investigate this further? Thanks! Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
