net: hns3: reduce stack usage in hclge_dbg_dump_tm_pri()

This function exceeds the stack frame warning limit:

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c: In function 'hclge_dbg_dump_tm_pri':
drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:1039:1: error: the frame size of 1408 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

Use dynamic allocation for the largest stack object instead. It
would be nice to rewrite this file to completely avoid the extra
buffer and just use the one that was already allocated by debugfs,
but that is a much larger change.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231204085735.4112882-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c
index ff3f8f424ad9004bbd549bc32cc43abca3ea2610..9ec471ced3d6271e741765407d4e9eea47e059bd 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c
@@ -981,19 +981,24 @@ static const struct hclge_dbg_item tm_pri_items[] = {
 
 static int hclge_dbg_dump_tm_pri(struct hclge_dev *hdev, char *buf, int len)
 {
-       char data_str[ARRAY_SIZE(tm_pri_items)][HCLGE_DBG_DATA_STR_LEN];
        struct hclge_tm_shaper_para c_shaper_para, p_shaper_para;
        char *result[ARRAY_SIZE(tm_pri_items)], *sch_mode_str;
        char content[HCLGE_DBG_TM_INFO_LEN];
        u8 pri_num, sch_mode, weight, i, j;
+       char *data_str;
        int pos, ret;
 
        ret = hclge_tm_get_pri_num(hdev, &pri_num);
        if (ret)
                return ret;
 
+       data_str = kcalloc(ARRAY_SIZE(tm_pri_items), HCLGE_DBG_DATA_STR_LEN,
+                          GFP_KERNEL);
+       if (!data_str)
+               return -ENOMEM;
+
        for (i = 0; i < ARRAY_SIZE(tm_pri_items); i++)
-               result[i] = &data_str[i][0];
+               result[i] = &data_str[i * HCLGE_DBG_DATA_STR_LEN];
 
        hclge_dbg_fill_content(content, sizeof(content), tm_pri_items,
                               NULL, ARRAY_SIZE(tm_pri_items));
@@ -1002,23 +1007,23 @@ static int hclge_dbg_dump_tm_pri(struct hclge_dev *hdev, char *buf, int len)
        for (i = 0; i < pri_num; i++) {
                ret = hclge_tm_get_pri_sch_mode(hdev, i, &sch_mode);
                if (ret)
-                       return ret;
+                       goto out;
 
                ret = hclge_tm_get_pri_weight(hdev, i, &weight);
                if (ret)
-                       return ret;
+                       goto out;
 
                ret = hclge_tm_get_pri_shaper(hdev, i,
                                              HCLGE_OPC_TM_PRI_C_SHAPPING,
                                              &c_shaper_para);
                if (ret)
-                       return ret;
+                       goto out;
 
                ret = hclge_tm_get_pri_shaper(hdev, i,
                                              HCLGE_OPC_TM_PRI_P_SHAPPING,
                                              &p_shaper_para);
                if (ret)
-                       return ret;
+                       goto out;
 
                sch_mode_str = sch_mode & HCLGE_TM_TX_SCHD_DWRR_MSK ? "dwrr" :
                               "sp";
@@ -1035,7 +1040,9 @@ static int hclge_dbg_dump_tm_pri(struct hclge_dev *hdev, char *buf, int len)
                pos += scnprintf(buf + pos, len - pos, "%s", content);
        }
 
-       return 0;
+out:
+       kfree(data_str);
+       return ret;
 }
 
 static const struct hclge_dbg_item tm_qset_items[] = {