diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2025-02-21 09:57:25 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-02 07:59:20 +0200 |
| commit | b5f8b03af51543cff80a3986736bc79f6f5ccd52 (patch) | |
| tree | 464449af1687a3b951f0d531174cb009d85ad461 | |
| parent | 47ab2caba495c1d6a899d284e541a8df656dcfe9 (diff) | |
ntb: reduce stack usage in idt_scan_mws
[ 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>
| -rw-r--r-- | drivers/ntb/hw/idt/ntb_hw_idt.c | 18 |
1 files 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 6fc9dfe82474..419de7038570 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; } /* |