From: Roy Novich royno@nvidia.com
[ Upstream commit 162bd18eb55adf464a0fa2b4144b8d61c75ff7c2 ]
Add return value for dim_calc_stats. This is an indication for the caller if curr_stats was assigned by the function. Avoid using curr_stats uninitialized over {rdma/net}_dim, when no time delta between samples. Coverity reported this potential use of an uninitialized variable.
Fixes: 4c4dbb4a7363 ("net/mlx5e: Move dynamic interrupt coalescing code to include/linux") Fixes: cb3c7fd4f839 ("net/mlx5e: Support adaptive RX coalescing") Signed-off-by: Roy Novich royno@nvidia.com Reviewed-by: Aya Levin ayal@nvidia.com Reviewed-by: Saeed Mahameed saeedm@nvidia.com Signed-off-by: Tariq Toukan tariqt@nvidia.com Reviewed-by: Leon Romanovsky leonro@nvidia.com Reviewed-by: Michal Kubiak michal.kubiak@intel.com Link: https://lore.kernel.org/r/20230507135743.138993-1-tariqt@nvidia.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/dim.h | 3 ++- lib/dim/dim.c | 5 +++-- lib/dim/net_dim.c | 3 ++- lib/dim/rdma_dim.c | 3 ++- 4 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/include/linux/dim.h b/include/linux/dim.h index 6c5733981563e..f343bc9aa2ec9 100644 --- a/include/linux/dim.h +++ b/include/linux/dim.h @@ -236,8 +236,9 @@ void dim_park_tired(struct dim *dim); * * Calculate the delta between two samples (in data rates). * Takes into consideration counter wrap-around. + * Returned boolean indicates whether curr_stats are reliable. */ -void dim_calc_stats(struct dim_sample *start, struct dim_sample *end, +bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end, struct dim_stats *curr_stats);
/** diff --git a/lib/dim/dim.c b/lib/dim/dim.c index 38045d6d05381..e89aaf07bde50 100644 --- a/lib/dim/dim.c +++ b/lib/dim/dim.c @@ -54,7 +54,7 @@ void dim_park_tired(struct dim *dim) } EXPORT_SYMBOL(dim_park_tired);
-void dim_calc_stats(struct dim_sample *start, struct dim_sample *end, +bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end, struct dim_stats *curr_stats) { /* u32 holds up to 71 minutes, should be enough */ @@ -66,7 +66,7 @@ void dim_calc_stats(struct dim_sample *start, struct dim_sample *end, start->comp_ctr);
if (!delta_us) - return; + return false;
curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us); curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us); @@ -79,5 +79,6 @@ void dim_calc_stats(struct dim_sample *start, struct dim_sample *end, else curr_stats->cpe_ratio = 0;
+ return true; } EXPORT_SYMBOL(dim_calc_stats); diff --git a/lib/dim/net_dim.c b/lib/dim/net_dim.c index 53f6b9c6e9366..4e32f7aaac86c 100644 --- a/lib/dim/net_dim.c +++ b/lib/dim/net_dim.c @@ -227,7 +227,8 @@ void net_dim(struct dim *dim, struct dim_sample end_sample) dim->start_sample.event_ctr); if (nevents < DIM_NEVENTS) break; - dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats); + if (!dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats)) + break; if (net_dim_decision(&curr_stats, dim)) { dim->state = DIM_APPLY_NEW_PROFILE; schedule_work(&dim->work); diff --git a/lib/dim/rdma_dim.c b/lib/dim/rdma_dim.c index 15462d54758d3..88f7794867078 100644 --- a/lib/dim/rdma_dim.c +++ b/lib/dim/rdma_dim.c @@ -88,7 +88,8 @@ void rdma_dim(struct dim *dim, u64 completions) nevents = curr_sample->event_ctr - dim->start_sample.event_ctr; if (nevents < DIM_NEVENTS) break; - dim_calc_stats(&dim->start_sample, curr_sample, &curr_stats); + if (!dim_calc_stats(&dim->start_sample, curr_sample, &curr_stats)) + break; if (rdma_dim_decision(&curr_stats, dim)) { dim->state = DIM_APPLY_NEW_PROFILE; schedule_work(&dim->work);