From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Subject: drivers/block/null_blk_main.c: fix uninitialized var warnings With gcc-7.2, many instances of drivers/block/null_blk_main.c: In function ‘nullb_device_zone_nr_conv_store’: drivers/block/null_blk_main.c:291:12: warning: ‘new_value’ may be used uninitialized in this function [-Wmaybe-uninitialized] dev->NAME = new_value; \ ^ drivers/block/null_blk_main.c:279:7: note: ‘new_value’ was declared here TYPE new_value; \ ^ Presumably notabug, so use uninitialized_var() to suppress them. Cc: Shaohua Li <shli@xxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/block/null_blk_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/block/null_blk_main.c~drivers-block-null_blk_mainc-fix-uninitialized-var-warnings +++ a/drivers/block/null_blk_main.c @@ -276,7 +276,7 @@ nullb_device_##NAME##_store(struct confi { \ int (*apply_fn)(struct nullb_device *dev, TYPE new_value) = APPLY;\ struct nullb_device *dev = to_nullb_device(item); \ - TYPE new_value; \ + TYPE uninitialized_var(new_value); \ int ret; \ \ ret = nullb_device_##TYPE##_attr_store(&new_value, page, count);\ _