5.4-stable review patch. If anyone has any objections, please let me know.
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From: Yury Norov [NVIDIA] yury.norov@gmail.com
[ Upstream commit 59f7d2138591ef8f0e4e4ab5f1ab674e8181ad3a ]
The function divides number of online CPUs by num_core_siblings, and later checks the divider by zero. This implies a possibility to get and divide-by-zero runtime error. Fix it by moving the check prior to division. This also helps to save one indentation level.
Signed-off-by: Yury Norov [NVIDIA] yury.norov@gmail.com Link: https://patch.msgid.link/20250604193947.11834-3-yury.norov@gmail.com Signed-off-by: Leon Romanovsky leon@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/hfi1/affinity.c | 44 +++++++++++++++------------ 1 file changed, 24 insertions(+), 20 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/affinity.c b/drivers/infiniband/hw/hfi1/affinity.c index 832b878fa67e..6933fbea2b46 100644 --- a/drivers/infiniband/hw/hfi1/affinity.c +++ b/drivers/infiniband/hw/hfi1/affinity.c @@ -1009,31 +1009,35 @@ static void find_hw_thread_mask(uint hw_thread_no, cpumask_var_t hw_thread_mask, struct hfi1_affinity_node_list *affinity) { int possible, curr_cpu, i; - uint num_cores_per_socket = node_affinity.num_online_cpus / + uint num_cores_per_socket; + + cpumask_copy(hw_thread_mask, &affinity->proc.mask); + + if (affinity->num_core_siblings == 0) + return; + + num_cores_per_socket = node_affinity.num_online_cpus / affinity->num_core_siblings / node_affinity.num_online_nodes;
- cpumask_copy(hw_thread_mask, &affinity->proc.mask); - if (affinity->num_core_siblings > 0) { - /* Removing other siblings not needed for now */ - possible = cpumask_weight(hw_thread_mask); - curr_cpu = cpumask_first(hw_thread_mask); - for (i = 0; - i < num_cores_per_socket * node_affinity.num_online_nodes; - i++) - curr_cpu = cpumask_next(curr_cpu, hw_thread_mask); - - for (; i < possible; i++) { - cpumask_clear_cpu(curr_cpu, hw_thread_mask); - curr_cpu = cpumask_next(curr_cpu, hw_thread_mask); - } + /* Removing other siblings not needed for now */ + possible = cpumask_weight(hw_thread_mask); + curr_cpu = cpumask_first(hw_thread_mask); + for (i = 0; + i < num_cores_per_socket * node_affinity.num_online_nodes; + i++) + curr_cpu = cpumask_next(curr_cpu, hw_thread_mask);
- /* Identifying correct HW threads within physical cores */ - cpumask_shift_left(hw_thread_mask, hw_thread_mask, - num_cores_per_socket * - node_affinity.num_online_nodes * - hw_thread_no); + for (; i < possible; i++) { + cpumask_clear_cpu(curr_cpu, hw_thread_mask); + curr_cpu = cpumask_next(curr_cpu, hw_thread_mask); } + + /* Identifying correct HW threads within physical cores */ + cpumask_shift_left(hw_thread_mask, hw_thread_mask, + num_cores_per_socket * + node_affinity.num_online_nodes * + hw_thread_no); }
int hfi1_get_proc_affinity(int node)