Subject: Re: [PATCH 1/2] net/mlx5: pre-initialize sprintf buffers

From: Zhu Yanjun <[email-masked]>
Date: Tue, 20 Feb 2024 13:50:47 +0800

在 2024/2/19 18:04, Arnd Bergmann 写道:
> From: Arnd Bergmann <[email-masked]>
> 
> The debugfs files always in this driver all use an extra round-trip
> through an snprintf() before getting put into a mlx5dr_dbg_dump_buff()
> rather than the normal seq_printf().
> 
> Zhu Yanjun noticed that the buffers are not initialized before being
> filled or reused and requested them to always be zeroed as a
> preparation for having more reused between the buffers.

I think that you are the first to find this.

Thanks,
Zhu Yanjun

> 
> Requested-by: Zhu Yanjun <[email-masked]>
> Signed-off-by: Arnd Bergmann <[email-masked]>
> ---
>   .../mellanox/mlx5/core/steering/dr_dbg.c      | 35 +++++++++++++++++++
>   1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c
> index 64f4cc284aea..be7a8481d7d2 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c
> @@ -217,6 +217,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   
>   	switch (action->action_type) {
>   	case DR_ACTION_TYP_DROP:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx\n",
>   			       DR_DUMP_REC_TYPE_ACTION_DROP, action_id,
> @@ -229,6 +230,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_FT:
> +		memset(buff, 0, sizeof(buff));
>   		if (action->dest_tbl->is_fw_tbl)
>   			ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   				       "%d,0x%llx,0x%llx,0x%x,0x%x\n",
> @@ -250,6 +252,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_CTR:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_CTR, action_id, rule_id,
> @@ -262,6 +265,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_TAG:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_TAG, action_id, rule_id,
> @@ -283,6 +287,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   
>   		ptrn_arg = !action->rewrite->single_action_opt && ptrn && arg;
>   
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x,%d,0x%x,0x%x,0x%x",
>   			       DR_DUMP_REC_TYPE_ACTION_MODIFY_HDR, action_id,
> @@ -300,6 +305,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   
>   		if (ptrn_arg) {
>   			for (i = 0; i < action->rewrite->num_of_actions; i++) {
> +				memset(buff, 0, sizeof(buff));
>   				ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   					       ",0x%016llx",
>   					       be64_to_cpu(((__be64 *)rewrite_data)[i]));
> @@ -321,6 +327,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   		break;
>   	}
>   	case DR_ACTION_TYP_VPORT:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_VPORT, action_id, rule_id,
> @@ -333,6 +340,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_TNL_L2_TO_L2:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx\n",
>   			       DR_DUMP_REC_TYPE_ACTION_DECAP_L2, action_id,
> @@ -345,6 +353,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_TNL_L3_TO_L2:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_DECAP_L3, action_id,
> @@ -360,6 +369,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_L2_TO_TNL_L2:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_ENCAP_L2, action_id,
> @@ -372,6 +382,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_L2_TO_TNL_L3:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_ENCAP_L3, action_id,
> @@ -384,6 +395,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_POP_VLAN:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx\n",
>   			       DR_DUMP_REC_TYPE_ACTION_POP_VLAN, action_id,
> @@ -396,6 +408,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_PUSH_VLAN:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_PUSH_VLAN, action_id,
> @@ -408,6 +421,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_INSERT_HDR:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x,0x%x,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_INSERT_HDR, action_id,
> @@ -422,6 +436,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_REMOVE_HDR:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x,0x%x,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_REMOVE_HDR, action_id,
> @@ -436,6 +451,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   			return ret;
>   		break;
>   	case DR_ACTION_TYP_SAMPLER:
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x,0x%x,0x%x,0x%llx,0x%llx\n",
>   			       DR_DUMP_REC_TYPE_ACTION_SAMPLER, action_id,
> @@ -468,6 +484,7 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
>   				DR_DBG_PTR_TO_ID(action->range->miss_tbl_action->dest_tbl->tbl);
>   		}
>   
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,0x%llx,0x%x,0x%llx,0x%x,0x%llx,0x%x\n",
>   			       DR_DUMP_REC_TYPE_ACTION_MATCH_RANGE, action_id,
> @@ -507,6 +524,7 @@ dr_dump_rule_mem(struct seq_file *file, struct mlx5dr_ste *ste,
>   	dr_dump_hex_print(hw_ste_dump, (char *)mlx5dr_ste_get_hw_ste(ste),
>   			  DR_STE_SIZE_REDUCED);
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,0x%llx,%s\n", mem_rec_type,
>   		       dr_dump_icm_to_idx(mlx5dr_ste_get_icm_addr(ste)),
> @@ -554,6 +572,7 @@ static int dr_dump_rule(struct seq_file *file, struct mlx5dr_rule *rule)
>   
>   	format_ver = rule->matcher->tbl->dmn->info.caps.sw_format_ver;
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,0x%llx\n", DR_DUMP_REC_TYPE_RULE,
>   		       rule_id, DR_DBG_PTR_TO_ID(rule->matcher));
> @@ -593,6 +612,7 @@ dr_dump_matcher_mask(struct seq_file *file, struct mlx5dr_match_param *mask,
>   	char dump[DR_HEX_SIZE];
>   	int ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH, "%d,0x%llx,",
>   		       DR_DUMP_REC_TYPE_MATCHER_MASK, matcher_id);
>   	if (ret < 0)
> @@ -602,6 +622,7 @@ dr_dump_matcher_mask(struct seq_file *file, struct mlx5dr_match_param *mask,
>   	if (ret)
>   		return ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	if (criteria & DR_MATCHER_CRITERIA_OUTER) {
>   		dr_dump_hex_print(dump, (char *)&mask->outer, sizeof(mask->outer));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
> @@ -617,6 +638,7 @@ dr_dump_matcher_mask(struct seq_file *file, struct mlx5dr_match_param *mask,
>   	if (ret)
>   		return ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	if (criteria & DR_MATCHER_CRITERIA_INNER) {
>   		dr_dump_hex_print(dump, (char *)&mask->inner, sizeof(mask->inner));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
> @@ -632,6 +654,7 @@ dr_dump_matcher_mask(struct seq_file *file, struct mlx5dr_match_param *mask,
>   	if (ret)
>   		return ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	if (criteria & DR_MATCHER_CRITERIA_MISC) {
>   		dr_dump_hex_print(dump, (char *)&mask->misc, sizeof(mask->misc));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
> @@ -647,6 +670,7 @@ dr_dump_matcher_mask(struct seq_file *file, struct mlx5dr_match_param *mask,
>   	if (ret)
>   		return ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	if (criteria & DR_MATCHER_CRITERIA_MISC2) {
>   		dr_dump_hex_print(dump, (char *)&mask->misc2, sizeof(mask->misc2));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
> @@ -662,6 +686,7 @@ dr_dump_matcher_mask(struct seq_file *file, struct mlx5dr_match_param *mask,
>   	if (ret)
>   		return ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	if (criteria & DR_MATCHER_CRITERIA_MISC3) {
>   		dr_dump_hex_print(dump, (char *)&mask->misc3, sizeof(mask->misc3));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
> @@ -687,6 +712,7 @@ dr_dump_matcher_builder(struct seq_file *file, struct mlx5dr_ste_build *builder,
>   	char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
>   	int ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,%d,%d,0x%x\n",
>   		       DR_DUMP_REC_TYPE_MATCHER_BUILDER, matcher_id, index,
> @@ -716,6 +742,7 @@ dr_dump_matcher_rx_tx(struct seq_file *file, bool is_rx,
>   
>   	s_icm_addr = mlx5dr_icm_pool_get_chunk_icm_addr(matcher_rx_tx->s_htbl->chunk);
>   	e_icm_addr = mlx5dr_icm_pool_get_chunk_icm_addr(matcher_rx_tx->e_anchor->chunk);
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,0x%llx,%d,0x%llx,0x%llx\n",
>   		       rec_type, DR_DBG_PTR_TO_ID(matcher_rx_tx),
> @@ -752,6 +779,7 @@ dr_dump_matcher(struct seq_file *file, struct mlx5dr_matcher *matcher)
>   
>   	matcher_id = DR_DBG_PTR_TO_ID(matcher);
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,0x%llx,%d\n", DR_DUMP_REC_TYPE_MATCHER,
>   		       matcher_id, DR_DBG_PTR_TO_ID(matcher->tbl),
> @@ -816,6 +844,7 @@ dr_dump_table_rx_tx(struct seq_file *file, bool is_rx,
>   			   DR_DUMP_REC_TYPE_TABLE_TX;
>   
>   	s_icm_addr = mlx5dr_icm_pool_get_chunk_icm_addr(table_rx_tx->s_anchor->chunk);
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,0x%llx\n", rec_type, table_id,
>   		       dr_dump_icm_to_idx(s_icm_addr));
> @@ -836,6 +865,7 @@ static int dr_dump_table(struct seq_file *file, struct mlx5dr_table *table)
>   	char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
>   	int ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,0x%llx,%d,%d\n", DR_DUMP_REC_TYPE_TABLE,
>   		       DR_DBG_PTR_TO_ID(table), DR_DBG_PTR_TO_ID(table->dmn),
> @@ -887,6 +917,7 @@ dr_dump_send_ring(struct seq_file *file, struct mlx5dr_send_ring *ring,
>   	char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
>   	int ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,0x%llx,0x%x,0x%x\n",
>   		       DR_DUMP_REC_TYPE_DOMAIN_SEND_RING,
> @@ -911,6 +942,7 @@ dr_dump_domain_info_flex_parser(struct seq_file *file,
>   	char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
>   	int ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,%s,0x%x\n",
>   		       DR_DUMP_REC_TYPE_DOMAIN_INFO_FLEX_PARSER, domain_id,
> @@ -937,6 +969,7 @@ dr_dump_domain_info_caps(struct seq_file *file, struct mlx5dr_cmd_caps *caps,
>   	xa_for_each(&caps->vports.vports_caps_xa, vports_num, vport_caps)
>   		; /* count the number of vports in xarray */
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,0x%x,0x%llx,0x%llx,0x%x,%lu,%d\n",
>   		       DR_DUMP_REC_TYPE_DOMAIN_INFO_CAPS, domain_id, caps->gvmi,
> @@ -952,6 +985,7 @@ dr_dump_domain_info_caps(struct seq_file *file, struct mlx5dr_cmd_caps *caps,
>   	xa_for_each(&caps->vports.vports_caps_xa, i, vport_caps) {
>   		vport_caps = xa_load(&caps->vports.vports_caps_xa, i);
>   
> +		memset(buff, 0, sizeof(buff));
>   		ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   			       "%d,0x%llx,%lu,0x%x,0x%llx,0x%llx\n",
>   			       DR_DUMP_REC_TYPE_DOMAIN_INFO_VPORT,
> @@ -1012,6 +1046,7 @@ dr_dump_domain(struct seq_file *file, struct mlx5dr_domain *dmn)
>   	u64 domain_id = DR_DBG_PTR_TO_ID(dmn);
>   	int ret;
>   
> +	memset(buff, 0, sizeof(buff));
>   	ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
>   		       "%d,0x%llx,%d,0%x,%d,%u.%u.%u,%s,%d,%u,%u,%u\n",
>   		       DR_DUMP_REC_TYPE_DOMAIN,