Re: [PATCH] net/mlx5: fix possible stack overflows

Zhu Yanjun
2024-02-15T00:19:06Z

在 2024/2/13 18:08, Arnd Bergmann 写道:
> From: Arnd Bergmann <arnd@arndb.de>
>
> A couple of debug functions use a 512 byte temporary buffer and call another
> function that has another buffer of the same size, which in turn exceeds the
> usual warning limit for excessive stack usage:
>
> drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c:1073:1: error: stack frame size (1448) exceeds limit (1024) in 'dr_dump_start' [-Werror,-Wframe-larger-than]
> dr_dump_start(struct seq_file *file, loff_t *pos)
> drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c:1009:1: error: stack frame size (1120) exceeds limit (1024) in 'dr_dump_domain' [-Werror,-Wframe-larger-than]
> dr_dump_domain(struct seq_file *file, struct mlx5dr_domain *dmn)
> drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c:705:1: error: stack frame size (1104) exceeds limit (1024) in 'dr_dump_matcher_rx_tx' [-Werror,-Wframe-larger-than]
> dr_dump_matcher_rx_tx(struct seq_file *file, bool is_rx,
>
> Rework these so that each of the various code paths only ever has one of
> these buffers in it, and exactly the functions that declare one have
> the 'noinline_for_stack' annotation that prevents them from all being
> inlined into the same caller.
>
> Fixes: 917d1e799ddf ("net/mlx5: DR, Change SWS usage to debug fs seq_file interface")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> .../mellanox/mlx5/core/steering/dr_dbg.c | 82 +++++++++----------
> 1 file changed, 41 insertions(+), 41 deletions(-)
>
> 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..030a5776c937 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c
> @@ -205,12 +205,11 @@ dr_dump_hex_print(char hex[DR_HEX_SIZE], char *src, u32 size)
> }
>
> static int
> -dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
> +dr_dump_rule_action_mem(struct seq_file *file, char *buff, const u64 rule_id,
> struct mlx5dr_rule_action_member *action_mem)
> {
> struct mlx5dr_action *action = action_mem->action;
> const u64 action_id = DR_DBG_PTR_TO_ID(action);
> - char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
> u64 hit_tbl_ptr, miss_tbl_ptr;
> u32 hit_tbl_id, miss_tbl_id;
> int ret;
> @@ -488,10 +487,9 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
> }
>
> static int
> -dr_dump_rule_mem(struct seq_file *file, struct mlx5dr_ste *ste,
> +dr_dump_rule_mem(struct seq_file *file, char *buff, struct mlx5dr_ste *ste,
> bool is_rx, const u64 rule_id, u8 format_ver)
> {
> - char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
> char hw_ste_dump[DR_HEX_SIZE];
> u32 mem_rec_type;
> int ret;
> @@ -522,7 +520,8 @@ dr_dump_rule_mem(struct seq_file *file, struct mlx5dr_ste *ste,
> }
>
> static int
> -dr_dump_rule_rx_tx(struct seq_file *file, struct mlx5dr_rule_rx_tx *rule_rx_tx,
> +dr_dump_rule_rx_tx(struct seq_file *file, char *buff,
> + struct mlx5dr_rule_rx_tx *rule_rx_tx,
> bool is_rx, const u64 rule_id, u8 format_ver)
> {
> struct mlx5dr_ste *ste_arr[DR_RULE_MAX_STES + DR_ACTION_MAX_STES];
> @@ -533,7 +532,7 @@ dr_dump_rule_rx_tx(struct seq_file *file, struct mlx5dr_rule_rx_tx *rule_rx_tx,
> return 0;
>
> while (i--) {
> - ret = dr_dump_rule_mem(file, ste_arr[i], is_rx, rule_id,

Before buff is reused, I am not sure whether buff should be firstly
zeroed or not.

Zhu Yanjun

> + ret = dr_dump_rule_mem(file, buff, ste_arr[i], is_rx, rule_id,
> format_ver);
> if (ret < 0)
> return ret;
> @@ -542,7 +541,8 @@ dr_dump_rule_rx_tx(struct seq_file *file, struct mlx5dr_rule_rx_tx *rule_rx_tx,
> return 0;
> }
>
> -static int dr_dump_rule(struct seq_file *file, struct mlx5dr_rule *rule)
> +static noinline_for_stack int
> +dr_dump_rule(struct seq_file *file, struct mlx5dr_rule *rule)
> {
> struct mlx5dr_rule_action_member *action_mem;
> const u64 rule_id = DR_DBG_PTR_TO_ID(rule);
> @@ -565,19 +565,19 @@ static int dr_dump_rule(struct seq_file *file, struct mlx5dr_rule *rule)
> return ret;
>
> if (rx->nic_matcher) {
> - ret = dr_dump_rule_rx_tx(file, rx, true, rule_id, format_ver);

> + ret = dr_dump_rule_rx_tx(file, buff, rx, true, rule_id, format_ver);
> if (ret < 0)
> return ret;
> }
>
> if (tx->nic_matcher) {
> - ret = dr_dump_rule_rx_tx(file, tx, false, rule_id, format_ver);
> + ret = dr_dump_rule_rx_tx(file, buff, tx, false, rule_id, format_ver);
> if (ret < 0)
> return ret;
> }
>
> list_for_each_entry(action_mem, &rule->rule_actions_list, list) {
> - ret = dr_dump_rule_action_mem(file, rule_id, action_mem);
> + ret = dr_dump_rule_action_mem(file, buff, rule_id, action_mem);
> if (ret < 0)
> return ret;
> }
> @@ -586,10 +586,10 @@ static int dr_dump_rule(struct seq_file *file, struct mlx5dr_rule *rule)
> }
>
> static int
> -dr_dump_matcher_mask(struct seq_file *file, struct mlx5dr_match_param *mask,
> +dr_dump_matcher_mask(struct seq_file *file, char *buff,
> + struct mlx5dr_match_param *mask,
> u8 criteria, const u64 matcher_id)
> {
> - char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
> char dump[DR_HEX_SIZE];
> int ret;
>
> @@ -681,10 +681,10 @@ dr_dump_matcher_mask(struct seq_file *file, struct mlx5dr_match_param *mask,
> }
>
> static int
> -dr_dump_matcher_builder(struct seq_file *file, struct mlx5dr_ste_build *builder,
> +dr_dump_matcher_builder(struct seq_file *file, char *buff,
> + struct mlx5dr_ste_build *builder,
> u32 index, bool is_rx, const u64 matcher_id)
> {
> - char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
> int ret;
>
> ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
> @@ -702,11 +702,10 @@ dr_dump_matcher_builder(struct seq_file *file, struct mlx5dr_ste_build *builder,
> }
>
> static int
> -dr_dump_matcher_rx_tx(struct seq_file *file, bool is_rx,
> +dr_dump_matcher_rx_tx(struct seq_file *file, char *buff, bool is_rx,
> struct mlx5dr_matcher_rx_tx *matcher_rx_tx,
> const u64 matcher_id)
> {
> - char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
> enum dr_dump_rec_type rec_type;
> u64 s_icm_addr, e_icm_addr;
> int i, ret;
> @@ -731,7 +730,7 @@ dr_dump_matcher_rx_tx(struct seq_file *file, bool is_rx,
> return ret;
>
> for (i = 0; i < matcher_rx_tx->num_of_builders; i++) {
> - ret = dr_dump_matcher_builder(file,
> + ret = dr_dump_matcher_builder(file, buff,
> &matcher_rx_tx->ste_builder[i],
> i, is_rx, matcher_id);
> if (ret < 0)
> @@ -741,7 +740,7 @@ dr_dump_matcher_rx_tx(struct seq_file *file, bool is_rx,
> return 0;
> }
>
> -static int
> +static noinline_for_stack int
> dr_dump_matcher(struct seq_file *file, struct mlx5dr_matcher *matcher)
> {
> struct mlx5dr_matcher_rx_tx *rx = &matcher->rx;
> @@ -763,19 +762,19 @@ dr_dump_matcher(struct seq_file *file, struct mlx5dr_matcher *matcher)
> if (ret)
> return ret;
>
> - ret = dr_dump_matcher_mask(file, &matcher->mask,
> + ret = dr_dump_matcher_mask(file, buff, &matcher->mask,
> matcher->match_criteria, matcher_id);
> if (ret < 0)
> return ret;
>
> if (rx->nic_tbl) {
> - ret = dr_dump_matcher_rx_tx(file, true, rx, matcher_id);
> + ret = dr_dump_matcher_rx_tx(file, buff, true, rx, matcher_id);
> if (ret < 0)
> return ret;
> }
>
> if (tx->nic_tbl) {
> - ret = dr_dump_matcher_rx_tx(file, false, tx, matcher_id);
> + ret = dr_dump_matcher_rx_tx(file, buff, false, tx, matcher_id);
> if (ret < 0)
> return ret;
> }
> @@ -803,11 +802,10 @@ dr_dump_matcher_all(struct seq_file *file, struct mlx5dr_matcher *matcher)
> }
>
> static int
> -dr_dump_table_rx_tx(struct seq_file *file, bool is_rx,
> +dr_dump_table_rx_tx(struct seq_file *file, char *buff, bool is_rx,
> struct mlx5dr_table_rx_tx *table_rx_tx,
> const u64 table_id)
> {
> - char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
> enum dr_dump_rec_type rec_type;
> u64 s_icm_addr;
> int ret;
> @@ -829,7 +827,8 @@ dr_dump_table_rx_tx(struct seq_file *file, bool is_rx,
> return 0;
> }
>
> -static int dr_dump_table(struct seq_file *file, struct mlx5dr_table *table)
> +static noinline_for_stack int
> +dr_dump_table(struct seq_file *file, struct mlx5dr_table *table)
> {
> struct mlx5dr_table_rx_tx *rx = &table->rx;
> struct mlx5dr_table_rx_tx *tx = &table->tx;
> @@ -848,14 +847,14 @@ static int dr_dump_table(struct seq_file *file, struct mlx5dr_table *table)
> return ret;
>
> if (rx->nic_dmn) {
> - ret = dr_dump_table_rx_tx(file, true, rx,
> + ret = dr_dump_table_rx_tx(file, buff, true, rx,
> DR_DBG_PTR_TO_ID(table));
> if (ret < 0)
> return ret;
> }
>
> if (tx->nic_dmn) {
> - ret = dr_dump_table_rx_tx(file, false, tx,
> + ret = dr_dump_table_rx_tx(file, buff, false, tx,
> DR_DBG_PTR_TO_ID(table));
> if (ret < 0)
> return ret;
> @@ -881,10 +880,10 @@ static int dr_dump_table_all(struct seq_file *file, struct mlx5dr_table *tbl)
> }
>
> static int
> -dr_dump_send_ring(struct seq_file *file, struct mlx5dr_send_ring *ring,
> +dr_dump_send_ring(struct seq_file *file, char *buff,
> + struct mlx5dr_send_ring *ring,
> const u64 domain_id)
> {
> - char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
> int ret;
>
> ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
> @@ -902,13 +901,13 @@ dr_dump_send_ring(struct seq_file *file, struct mlx5dr_send_ring *ring,
> return 0;
> }
>
> -static noinline_for_stack int
> +static int
> dr_dump_domain_info_flex_parser(struct seq_file *file,
> + char *buff,
> const char *flex_parser_name,
> const u8 flex_parser_value,
> const u64 domain_id)
> {
> - char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
> int ret;
>
> ret = snprintf(buff, MLX5DR_DEBUG_DUMP_BUFF_LENGTH,
> @@ -925,11 +924,11 @@ dr_dump_domain_info_flex_parser(struct seq_file *file,
> return 0;
> }
>
> -static noinline_for_stack int
> -dr_dump_domain_info_caps(struct seq_file *file, struct mlx5dr_cmd_caps *caps,
> +static int
> +dr_dump_domain_info_caps(struct seq_file *file, char *buff,
> + struct mlx5dr_cmd_caps *caps,
> const u64 domain_id)
> {
> - char buff[MLX5DR_DEBUG_DUMP_BUFF_LENGTH];
> struct mlx5dr_cmd_vport_cap *vport_caps;
> unsigned long i, vports_num;
> int ret;
> @@ -969,34 +968,35 @@ dr_dump_domain_info_caps(struct seq_file *file, struct mlx5dr_cmd_caps *caps,
> }
>
> static int
> -dr_dump_domain_info(struct seq_file *file, struct mlx5dr_domain_info *info,
> +dr_dump_domain_info(struct seq_file *file, char *buff,
> + struct mlx5dr_domain_info *info,
> const u64 domain_id)
> {
> int ret;
>
> - ret = dr_dump_domain_info_caps(file, &info->caps, domain_id);
> + ret = dr_dump_domain_info_caps(file, buff, &info->caps, domain_id);
> if (ret < 0)
> return ret;
>
> - ret = dr_dump_domain_info_flex_parser(file, "icmp_dw0",
> + ret = dr_dump_domain_info_flex_parser(file, buff, "icmp_dw0",
> info->caps.flex_parser_id_icmp_dw0,
> domain_id);
> if (ret < 0)
> return ret;
>
> - ret = dr_dump_domain_info_flex_parser(file, "icmp_dw1",
> + ret = dr_dump_domain_info_flex_parser(file, buff, "icmp_dw1",
> info->caps.flex_parser_id_icmp_dw1,
> domain_id);
> if (ret < 0)
> return ret;
>
> - ret = dr_dump_domain_info_flex_parser(file, "icmpv6_dw0",
> + ret = dr_dump_domain_info_flex_parser(file, buff, "icmpv6_dw0",
> info->caps.flex_parser_id_icmpv6_dw0,
> domain_id);
> if (ret < 0)
> return ret;
>
> - ret = dr_dump_domain_info_flex_parser(file, "icmpv6_dw1",
> + ret = dr_dump_domain_info_flex_parser(file, buff, "icmpv6_dw1",
> info->caps.flex_parser_id_icmpv6_dw1,
> domain_id);
> if (ret < 0)
> @@ -1032,12 +1032,12 @@ dr_dump_domain(struct seq_file *file, struct mlx5dr_domain *dmn)
> if (ret)
> return ret;
>
> - ret = dr_dump_domain_info(file, &dmn->info, domain_id);
> + ret = dr_dump_domain_info(file, buff, &dmn->info, domain_id);
> if (ret < 0)
> return ret;
>
> if (dmn->info.supp_sw_steering) {
> - ret = dr_dump_send_ring(file, dmn->send_ring, domain_id);
> + ret = dr_dump_send_ring(file, buff, dmn->send_ring, domain_id);
> if (ret < 0)
> return ret;
> }