From f44f1e7da7c8e3f4575d5d61c4df978496903fcc Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 23 May 2017 17:32:31 -0700 Subject: [PATCH] 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 ++++ arch/x86/um/setjmp_32.S | 16 ++++++++-------- arch/x86/um/setjmp_64.S | 16 ++++++++-------- 3 files changed, 20 insertions(+), 16 deletions(-) diff --git a/arch/um/Makefile b/arch/um/Makefile index 0ca46ede..6ca4f66 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 diff --git a/arch/x86/um/setjmp_32.S b/arch/x86/um/setjmp_32.S index b766792..3905319 100644 --- a/arch/x86/um/setjmp_32.S +++ b/arch/x86/um/setjmp_32.S @@ -16,9 +16,9 @@ .text .align 4 - .globl setjmp - .type setjmp, @function -setjmp: + .globl kernel_setjmp + .type kernel_setjmp, @function +kernel_setjmp: #ifdef _REGPARM movl %eax,%edx #else @@ -35,13 +35,13 @@ setjmp: movl %ecx,20(%edx) # Return address ret - .size setjmp,.-setjmp + .size kernel_setjmp,.-kernel_setjmp .text .align 4 - .globl longjmp - .type longjmp, @function -longjmp: + .globl kernel_longjmp + .type kernel_longjmp, @function +kernel_longjmp: #ifdef _REGPARM xchgl %eax,%edx #else @@ -55,4 +55,4 @@ longjmp: movl 16(%edx),%edi jmp *20(%edx) - .size longjmp,.-longjmp + .size kernel_longjmp,.-kernel_longjmp diff --git a/arch/x86/um/setjmp_64.S b/arch/x86/um/setjmp_64.S index 45f547b..c56942e 100644 --- a/arch/x86/um/setjmp_64.S +++ b/arch/x86/um/setjmp_64.S @@ -18,9 +18,9 @@ .text .align 4 - .globl setjmp - .type setjmp, @function -setjmp: + .globl kernel_setjmp + .type kernel_setjmp, @function +kernel_setjmp: pop %rsi # Return address, and adjust the stack xorl %eax,%eax # Return value movq %rbx,(%rdi) @@ -34,13 +34,13 @@ setjmp: movq %rsi,56(%rdi) # Return address ret - .size setjmp,.-setjmp + .size kernel_setjmp,.-kernel_setjmp .text .align 4 - .globl longjmp - .type longjmp, @function -longjmp: + .globl kernel_longjmp + .type kernel_longjmp, @function +kernel_longjmp: movl %esi,%eax # Return value (int) movq (%rdi),%rbx movq 8(%rdi),%rsp @@ -51,4 +51,4 @@ longjmp: movq 48(%rdi),%r15 jmp *56(%rdi) - .size longjmp,.-longjmp + .size kernel_longjmp,.-kernel_longjmp -- 2.7.4