2022-05-26 00:24:17

by Manfred Spraul

[permalink] [raw]
Subject: Re: [PATCH] ipc: Remove dead code in perform_atomic_semop()

On 5/24/22 20:22, Gautam Menghani wrote:
> Remove the line which is dead code. Fixes the clang scan warning:
> warning: Value stored to 'result' is never read [deadcode.DeadStores]
> result = curr->semval;
>
> Signed-off-by: Gautam Menghani <[email protected]>
Reviewed-by: Manfred Spraul <[email protected]>
> ---
> ipc/sem.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/ipc/sem.c b/ipc/sem.c
> index 0dbdb98fdf2d..156824bcda47 100644
> --- a/ipc/sem.c
> +++ b/ipc/sem.c
> @@ -766,7 +766,6 @@ static int perform_atomic_semop(struct sem_array *sma, struct sem_queue *q)
> for (sop = sops; sop < sops + nsops; sop++) {
> curr = &sma->sems[sop->sem_num];
> sem_op = sop->sem_op;
> - result = curr->semval;
>

A copy/paste mistake: The 1st loop in perform_atomic_semop() needs
result - because it must check for overflows.

The 2nd loop doesn't need it.

> if (sop->sem_flg & SEM_UNDO) {
> int undo = un->semadj[sop->sem_num] - sem_op;

--

    Manfred