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    elevator: fix truncation of icq_cache_name · 9bd2bbc0
    Eric Biggers 提交于
    gcc 7.1 reports the following warning:
    
        block/elevator.c: In function ‘elv_register’:
        block/elevator.c:898:5: warning: ‘snprintf’ output may be truncated before the last format character [-Wformat-truncation=]
             "%s_io_cq", e->elevator_name);
             ^~~~~~~~~~
        block/elevator.c:897:3: note: ‘snprintf’ output between 7 and 22 bytes into a destination of size 21
           snprintf(e->icq_cache_name, sizeof(e->icq_cache_name),
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
             "%s_io_cq", e->elevator_name);
             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
    The bug is that the name of the icq_cache is 6 characters longer than
    the elevator name, but only ELV_NAME_MAX + 5 characters were reserved
    for it --- so in the case of a maximum-length elevator name, the 'q'
    character in "_io_cq" would be truncated by snprintf().  Fix it by
    reserving ELV_NAME_MAX + 6 characters instead.
    Signed-off-by: NEric Biggers <ebiggers@google.com>
    Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
    Signed-off-by: NJens Axboe <axboe@fb.com>
    9bd2bbc0
elevator.h 9.3 KB