Re: [PATCH 0/7] gcov kernel support

[Segher Boessenkool <segher@kernel.crashing.org>]

>> This is version #2 of the gcov kernel support patch set
>
> powerpc blew up:
>
> /opt/crosstool/gcc-4.1.0-glibc-2.3.6/powerpc64-unknown-linux-gnu/lib/ 
> gcc/powerpc64-unknown-linux-gnu/4.1.0/../../../../powerpc64-unknown- 
> linux-gnu/bin/ld: skipping incompatible  
> /opt/crosstool/gcc-4.1.0-glibc-2.3.6/powerpc64-unknown-linux-gnu/lib/ 
> gcc/powerpc64-unknown-linux-gnu/4.1.0/./libgcov.a when searching for  
> -lgcov
> /opt/crosstool/gcc-4.1.0-glibc-2.3.6/powerpc64-unknown-linux-gnu/lib/ 
> gcc/powerpc64-unknown-linux-gnu/4.1.0/../../../../powerpc64-unknown- 
> linux-gnu/bin/ld: cannot find -lgcov
> collect2: ld returned 1 exit status
> make[2]: *** [arch/powerpc/kernel/vdso32/vdso32.so.dbg] Error 1
> make[1]: *** [arch/powerpc/kernel/vdso32] Error 2

Sounds like your toolchain was built without biarch support, but you're
using it for the 32-bit parts of the kernel anyway.  Which works as long
as you're not using any libraries, but now you need libgcov.a .

What does

/opt/crosstool/gcc-4.1.0-glibc-2.3.6/powerpc64-unknown-linux-gnu/bin/ 
powerpc64-unknown-linux-gnu-gcc -v

say?  (Or whatever the correct path to that compiler is, the directory
structure is a bit unusual here it seems).  There shouldn't be a
--disable-biarch there.

Or, what does

find  
/opt/crosstool/gcc-4.1.0-glibc-2.3.6/powerpc64-unknown-linux-gnu/4.1.0/  
-name libgcov.a

say?  (It should usually find three versions: 64-bit, 32-bit, 32-bit no  
float).


You *can* build with a non-biarch compiler, but then you need to point
the kernel build system at a 32-bit toolchain to use for the 32-bit
parts (via CROSS32_COMPILE).


Segher