From f44f1e7da7c8e3f4575d5d61c4df978496903fcc Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 23 May 2017 17:32:31 -0700 Subject: um: Avoid longjmp/setjmp symbol clashes with libpthread.a Building a statically linked UML kernel on a Centos 6.9 host resulted in the following linking failure (GCC 4.4, glibc-2.12): /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o): In function `siglongjmp': (.text+0x8490): multiple definition of `longjmp' arch/x86/um/built-in.o:/local/users/fainelli/openwrt/trunk/build_dir/target-x86_64_musl/linux-uml/linux-4.4.69/arch/x86/um/setjmp_64.S:44: first defined here /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o): In function `sem_open': (.text+0x77cd): warning: the use of `mktemp' is dangerous, better use `mkstemp' collect2: ld returned 1 exit status make[4]: *** [vmlinux] Error 1 Adopt a solution similar to the one done for vmap where we define longjmp/setjmp to be kernel_longjmp/setjmp. In the process, make sure we do rename the functions in arch/x86/um/setjmp_*.S accordingly. Fixes: a7df4716d195 ("um: link with -lpthread") Signed-off-by: Florian Fainelli Signed-off-by: Richard Weinberger --- arch/um/Makefile | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/um/Makefile') diff --git a/arch/um/Makefile b/arch/um/Makefile index 0ca46ededfc7..6ca4f66085c1 100644 --- a/arch/um/Makefile +++ b/arch/um/Makefile @@ -59,10 +59,14 @@ KBUILD_CPPFLAGS += -I$(srctree)/$(HOST_DIR)/um # Same things for in6addr_loopback and mktime - found in libc. For these two we # only get link-time error, luckily. # +# -Dlongjmp=kernel_longjmp prevents anything from referencing the libpthread.a +# embedded copy of longjmp, same thing for setjmp. +# # These apply to USER_CFLAGS to. KBUILD_CFLAGS += $(CFLAGS) $(CFLAGS-y) -D__arch_um__ \ $(ARCH_INCLUDE) $(MODE_INCLUDE) -Dvmap=kernel_vmap \ + -Dlongjmp=kernel_longjmp -Dsetjmp=kernel_setjmp \ -Din6addr_loopback=kernel_in6addr_loopback \ -Din6addr_any=kernel_in6addr_any -Dstrrchr=kernel_strrchr -- cgit v1.2.1