Hello,

Thank for a wonderful system library!

Revision f61be1f875a2758509d6e9e2cf6f1d9603b28b65 
<http://git.musl-libc.org/cgit/musl/commit/arch/mips/syscall_arch.h?id=f61be1f875a2758509d6e9e2cf6f1d9603b28b65> 
has led to regression with system calls of family *stat on MIPS with big 
endian byte order.
Upon successful completion, the system call returns the number from stat 
structure instead of 0.

_Information:
_Binutils 2.23.2/2.24
GCC 4.8.3/4.9.2
musl 1.1.5/1.1.8/HEAD

_Code to reproduce problem:_

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

int main(int argc, char *argv[])

{

         int fd, res = EXIT_FAILURE, ret;

         struct stat st;

         fd = open("/dev/urandom", O_RDONLY);

         if (fd < 0) {

                 perror("open");

                 goto out;

         }

         ret = fstat(fd, &st);

         if (ret < 0) {

                 perror("fstat");

                 goto out_close;

         } else {

                 printf("ret = %d\n", ret);

         }

         res = EXIT_SUCCESS;

out_close:

         close(fd);

out:

         return res;

}


_Output:_

# test_fstat

ret = 265


# strace -s 1024 test_fstat

execve("/bin/test_fstat", ["test_fstat"], [/* 7 vars */]) = 0

set_thread_area(0x2ae00764)             = 0

set_tid_address(0x2adf96b4)             = 150

open("/dev/urandom", O_RDONLY|O_LARGEFILE) = 3

fstat64(3, {st_mode=S_IFCHR|0600, st_rdev=makedev(1, 9), ...}) = 0

ioctl(1, TIOCNXCL, {B9600 opost isig icanon echo ...}) = 0

writev(1, [{"ret = 265", 9}, {"\n", 1}], 2ret = 265

) = 10

close(3)                                = 0

exit_group(0)                           = ?

+++ exited with 0 +++


The reason of the problem is that the function __stat_fix rewrites 
register $v0, which is not stored in the parent function.

Disassembled code of fstat64 is attached.
Patchis attachedalso.

Sorry for my english.