[PATCH] sysctl: Remove redundant assignment to first

[PATCH] sysctl: Remove redundant assignment to first

[Jiapeng Chong]

Variable first is set to '0', but this value is never read as it is
not used later on, hence it is a redundant assignment and can be
removed.

Clean up the following clang-analyzer warning:

kernel/sysctl.c:1562:4: warning: Value stored to 'first' is never read
[clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
---
 kernel/sysctl.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 14edf84..58beeba 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1559,7 +1559,6 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 			}
 
 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
-			first = 0;
 			proc_skip_char(&p, &left, '\n');
 		}
 		left += skipped;
-- 
1.8.3.1

Re: [PATCH] sysctl: Remove redundant assignment to first

[Matthew Wilcox]

On Fri, May 07, 2021 at 06:15:54PM +0800, Jiapeng Chong wrote:
> Variable first is set to '0', but this value is never read as it is
> not used later on, hence it is a redundant assignment and can be
> removed.
> 
> Clean up the following clang-analyzer warning:
> 
> kernel/sysctl.c:1562:4: warning: Value stored to 'first' is never read
> [clang-analyzer-deadcode.DeadStores].

While this is true, it is incomplete.  The 'first' declaration should be
moved into the 'else' arm of the 'if (write)' conditional.