Re: [PATCH] net: hns3: fix hclge_dbg_dump_tm_pg() stack usage
From: huangguangbin (A) <hidden>
Date: 2021-09-28 08:34:18
Also in:
lkml
On 2021/9/27 17:49, Arnd Bergmann wrote:
quoted hunk ↗ jump to hunk
From: Arnd Bergmann <arnd@arndb.de> This function copies strings around between multiple buffers including a large on-stack array that causes a build warning on 32-bit systems: drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c: In function 'hclge_dbg_dump_tm_pg': drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c:782:1: error: the frame size of 1424 bytes is larger than 1400 bytes [-Werror=frame-larger-than=] The function can probably be cleaned up a lot, to go back to printing directly into the output buffer, but dynamically allocating the structure is a simpler workaround for now. Fixes: 04d96139ddb3 ("net: hns3: refine function hclge_dbg_dump_tm_pri()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- .../hisilicon/hns3/hns3pf/hclge_debugfs.c | 26 ++++++++++++++++--- 1 file changed, 22 insertions(+), 4 deletions(-)diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c index 87d96f82c318..3ed87814100a 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c@@ -719,9 +719,9 @@ static void hclge_dbg_fill_shaper_content(struct hclge_tm_shaper_para *para, sprintf(result[(*index)++], "%6u", para->rate); } -static int hclge_dbg_dump_tm_pg(struct hclge_dev *hdev, char *buf, int len) +static int __hclge_dbg_dump_tm_pg(struct hclge_dev *hdev, char *data_str, + char *buf, int len) { - char data_str[ARRAY_SIZE(tm_pg_items)][HCLGE_DBG_DATA_STR_LEN]; struct hclge_tm_shaper_para c_shaper_para, p_shaper_para; char *result[ARRAY_SIZE(tm_pg_items)], *sch_mode_str; u8 pg_id, sch_mode, weight, pri_bit_map, i, j;@@ -729,8 +729,10 @@ static int hclge_dbg_dump_tm_pg(struct hclge_dev *hdev, char *buf, int len) int pos = 0; int ret; - for (i = 0; i < ARRAY_SIZE(tm_pg_items); i++) - result[i] = &data_str[i][0]; + for (i = 0; i < ARRAY_SIZE(tm_pg_items); i++) { + result[i] = data_str; + data_str += HCLGE_DBG_DATA_STR_LEN; + } hclge_dbg_fill_content(content, sizeof(content), tm_pg_items, NULL, ARRAY_SIZE(tm_pg_items));@@ -781,6 +783,22 @@ static int hclge_dbg_dump_tm_pg(struct hclge_dev *hdev, char *buf, int len) return 0; } +static int hclge_dbg_dump_tm_pg(struct hclge_dev *hdev, char *buf, int len) +{ + int ret; + char *data_str = kcalloc(ARRAY_SIZE(tm_pg_items), + HCLGE_DBG_DATA_STR_LEN, GFP_KERNEL); +
Hi Arnd, thanks your modification, according to linux code style, should the code be written as follow? char *data_str; int ret; data_str = kcalloc(ARRAY_SIZE(tm_pg_items), HCLGE_DBG_DATA_STR_LEN, GFP_KERNEL);
+ if (!data_str)
+ return -ENOMEM;
+
+ ret = __hclge_dbg_dump_tm_pg(hdev, data_str, buf, len);
+
+ kfree(data_str);
+
+ return ret;
+}
+
static int hclge_dbg_dump_tm_port(struct hclge_dev *hdev, char *buf, int len)
{
struct hclge_tm_shaper_para shaper_para;