Something wrong with setlocale(LC_ALL, "") in glibc ?

When cross-compiling a Montavista Linux kernel for PPC, I modified the
BSP and here comes the headache. Something wrong with my file system --
some shellutils are OK, like pwd; but some always cause segmentation
fault, like uname.
I tracked uname.c. I am sure the problem comes from the function call
setlocale(LC_ALL, ""). When I comment it out, uname will work fine. But
I find the same call in pwd.c. My question is, what might be wrong with
my glibc, or other problem?
Any feedback is deeply appreciated!