5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arnd Bergmann arnd@arndb.de
[ Upstream commit aff12700b8dd7422bfe2277696e192af4df9de8f ]
idt_scan_mws() puts a large fixed-size array on the stack and copies it into a smaller dynamically allocated array at the end. On 32-bit targets, the fixed size can easily exceed the warning limit for possible stack overflow:
drivers/ntb/hw/idt/ntb_hw_idt.c:1041:27: error: stack frame size (1032) exceeds limit (1024) in 'idt_scan_mws' [-Werror,-Wframe-larger-than]
Change it to instead just always use dynamic allocation for the array from the start. It's too big for the stack, but not actually all that much for a permanent allocation.
Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/all/202205111109.PiKTruEj-lkp@intel.com/ Signed-off-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Dave Jiang dave.jiang@intel.com Reviewed-by: Damien Le Moal dlemoal@kernel.org Signed-off-by: Jon Mason jdmason@kudzu.us Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ntb/hw/idt/ntb_hw_idt.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/drivers/ntb/hw/idt/ntb_hw_idt.c b/drivers/ntb/hw/idt/ntb_hw_idt.c index a0091900b0cfb..c74d958ffc62f 100644 --- a/drivers/ntb/hw/idt/ntb_hw_idt.c +++ b/drivers/ntb/hw/idt/ntb_hw_idt.c @@ -1041,7 +1041,7 @@ static inline char *idt_get_mw_name(enum idt_mw_type mw_type) static struct idt_mw_cfg *idt_scan_mws(struct idt_ntb_dev *ndev, int port, unsigned char *mw_cnt) { - struct idt_mw_cfg mws[IDT_MAX_NR_MWS], *ret_mws; + struct idt_mw_cfg *mws; const struct idt_ntb_bar *bars; enum idt_mw_type mw_type; unsigned char widx, bidx, en_cnt; @@ -1049,6 +1049,11 @@ static struct idt_mw_cfg *idt_scan_mws(struct idt_ntb_dev *ndev, int port, int aprt_size; u32 data;
+ mws = devm_kcalloc(&ndev->ntb.pdev->dev, IDT_MAX_NR_MWS, + sizeof(*mws), GFP_KERNEL); + if (!mws) + return ERR_PTR(-ENOMEM); + /* Retrieve the array of the BARs registers */ bars = portdata_tbl[port].bars;
@@ -1103,16 +1108,7 @@ static struct idt_mw_cfg *idt_scan_mws(struct idt_ntb_dev *ndev, int port, } }
- /* Allocate memory for memory window descriptors */ - ret_mws = devm_kcalloc(&ndev->ntb.pdev->dev, *mw_cnt, sizeof(*ret_mws), - GFP_KERNEL); - if (!ret_mws) - return ERR_PTR(-ENOMEM); - - /* Copy the info of detected memory windows */ - memcpy(ret_mws, mws, (*mw_cnt)*sizeof(*ret_mws)); - - return ret_mws; + return mws; }
/*