• Nathan Chancellor's avatar
    misc: sgi-xp: Properly initialize buf in xpc_get_rsvd_page_pa · 5004fece
    Nathan Chancellor authored
    [ Upstream commit b0576f9e ]
    
    Clang warns:
    
    drivers/misc/sgi-xp/xpc_partition.c:73:14: warning: variable 'buf' is
    uninitialized when used within its own initialization [-Wuninitialized]
            void *buf = buf;
                  ~~~   ^~~
    1 warning generated.
    
    Arnd's explanation during review:
    
      /*
       * Returns the physical address of the partition's reserved page through
       * an iterative number of calls.
       *
       * On first call, 'cookie' and 'len' should be set to 0, and 'addr'
       * set to the nasid of the partition whose reserved page's address is
       * being sought.
       * On subsequent calls, pass the values, that were passed back on the
       * previous call.
       *
       * While the return status equals SALRET_MORE_PASSES, keep calling
       * this function after first copying 'len' bytes starting at 'addr'
       * into 'buf'. Once the return status equals SALRET_OK, 'addr' will
       * be the physical address of the partition's reserved page. If the
       * return status equals neither of these, an error as occurred.
       */
      static inline s64
      sn_partition_reserved_page_pa(u64 buf, u64 *cookie, u64 *addr, u64 *len)
    
      so *len is set to zero on the first call and tells the bios how many
      bytes are accessible at 'buf', and it does get updated by the BIOS to
      tell us how many bytes it needs, and then we allocate that and try again.
    
    Fixes: 27929029 ("[IA64-SGI] cleanup the way XPC locates the reserved page")
    Link: https://github.com/ClangBuiltLinux/linux/issues/466Suggested-by: default avatarStephen Hines <srhines@google.com>
    Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
    Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
    Signed-off-by: default avatarNathan Chancellor <natechancellor@gmail.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
    5004fece
xpc_partition.c 13.7 KB