• Helge Deller's avatar
    parisc: fix fanotify_mark() syscall on 32bit compat kernel · ab8a261b
    Helge Deller authored
    
    
    On parisc we can not use the existing compat implementation for fanotify_mark()
    because for the 64bit mask parameter the higher and lower 32bits are ordered
    differently than what the compat function expects from big endian
    architectures.
    
    Specifically:
    It finally turned out, that on hppa we end up with different assignments
    of parameters to kernel arguments depending on if we call the glibc
    wrapper function
     int fanotify_mark (int __fanotify_fd, unsigned int __flags,
                        uint64_t __mask, int __dfd, const char *__pathname);
    or directly calling the syscall manually
     syscall(__NR_fanotify_mark, ...)
    
    Reason is, that the syscall() function is implemented as C-function and
    because we now have the sysno as first parameter in front of the other
    parameters the compiler will unexpectedly add an empty paramenter in
    front of the u64 value to ensure the correct calling alignment for 64bit
    values.
    This means, on hppa you can't simply use syscall() to call the kernel
    fanotify_mark() function directly, but you have to use the glibc
    function instead.
    
    This patch fixes the kernel in the hppa-arch specifc coding to adjust
    the parameters in a way as if userspace calls the glibc wrapper function
    fanotify_mark().
    Signed-off-by: default avatarHelge Deller <deller@gmx.de>
    Cc: stable@vger.kernel.org # 3.13+
    ab8a261b
syscall_table.S 13.2 KB