On Thu, Jul 09, 2020 at 01:48:18PM +0300, Dan Carpenter wrote:
> The __per_cpu_offset[] array has "nr_cpu_ids" elements so change the >
> >= to prevent a read one element beyond the end of the array.
>
> Fixes: 0504bc41a62c ("kernel/smp: Provide CSD lock timeout diagnostics")
I don't have a copy of that patch in my inbox, even though it says Cc:
me.
Paul, where do you expect that patch to go? The version I see from my
next tree needs a _lot_ of work.
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> kernel/smp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/smp.c b/kernel/smp.c
> index 78b602cae6c2..f49966713ac3 100644
> --- a/kernel/smp.c
> +++ b/kernel/smp.c
> @@ -171,7 +171,7 @@ static __always_inline bool csd_lock_wait_toolong(call_single_data_t *csd, u64 t
> *bug_id = atomic_inc_return(&csd_bug_count);
> cpu = csd_lock_wait_getcpu(csd);
> smp_mb(); // No stale cur_csd values!
> - if (WARN_ONCE(cpu < 0 || cpu > nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu))
> + if (WARN_ONCE(cpu < 0 || cpu >= nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu))
> cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, 0));
> else
> cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, cpu));
> --
> 2.27.0
>
