Commit f44f1e7d authored by Florian Fainelli's avatar Florian Fainelli Committed by Richard Weinberger
Browse files

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: a7df4716 ("um: link with -lpthread")
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 745a600c

arch/um/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/um/setjmp_32.S

+8 −8
Original line number Diff line number Diff line
@@ -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

arch/x86/um/setjmp_64.S

+8 −8
Original line number Diff line number Diff line
@@ -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

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