Messages in this thread | | | Date | Fri, 17 Apr 2015 22:47:05 -0700 | From | Guenter Roeck <> | Subject | sparc64: Build failure due to commit f1600e549b94 (sparc: Make sparc64 use scalable lib/iommu-common.c functions) |
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Hi all,
I see the following build failure when compiling sparc64:allmodconfig in the upstream kernel (v4.0-7820-g04b7fe6a4a23).
arch/sparc/kernel/pci_sun4v.o:(.discard+0x1): multiple definition of `__pcpu_unique_iommu_pool_hash' arch/sparc/kernel/iommu.o:(.discard+0x0): first defined here make[2]: *** [arch/sparc/kernel/built-in.o] Error 1 make[1]: *** [arch/sparc/kernel] Error 2
The problem is caused by commit f1600e549b94 ("sparc: Make sparc64 use scalable lib/iommu-common.c functions"), which introduces
static DEFINE_PER_CPU(unsigned int, iommu_pool_hash);
in both files.
DEFINE_PER_CPU translates to DEFINE_PER_CPU_SECTION, which in turn is defined as
#define DEFINE_PER_CPU_SECTION(type, name, sec) \ __PCPU_DUMMY_ATTRS char __pcpu_scope_##name; \ extern __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \ --> __PCPU_DUMMY_ATTRS char __pcpu_unique_##name; \ extern __PCPU_ATTRS(sec) __typeof__(type) name; \ __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak \ __typeof__(type) name
if CONFIG_DEBUG_FORCE_WEAK_PER_CPU is configured, which is the case here. The marked line above shows that __pcpu_unique_iommu_pool_hash is declared as global variable, which explains the problem (and makes me wonder what the 'static' keyword in front of DEFINE_PER_CPU is supposed to accomplish).
I thought about fixing the problem by renaming one of the variables, but I am not sure if that is what is intended. Specifically, I am not sure if the variables are supposed to be different, as it looks like, or if they are supposed to be the same.
In case it is relevant, I use gcc version 4.6.3 for my build test.
Guenter
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