From f07554557ff2dacb36e05343e54a3323d0e010e6 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 25 Sep 2026 15:07:36 +0200 Subject: [PATCH] wifi: b43legacy: work around stack frame size warning I came across a rare warning in the b43legacy driver while building randconfig kernels using clang-21.1.8, with KASAN enabled: drivers/net/wireless/broadcom/b43legacy/main.c:3250:12: error: stack frame size (1392) exceeds limit (1280) in 'b43legacy_wireless_core_init' [-Werror,-Wframe-larger-than] 3250 | static int b43legacy_wireless_core_init(struct b43legacy_wldev *dev) | ^ There are no actual large variables on the stack here, just excessive spills, and the code looks fine otherwise, so this is really an optimization quirk in the compiler. Marking the prepare_phy_data_for_init() function as noinline completely avoids the issue, with no function in this file using more than 200 bytes of stack space, same as without KASAN. Link: https://pastebin.com/raw/KpV124Ep # .config Link: https://pastebin.com/CxWfsBN0 # assembler output, truncated Signed-off-by: Arnd Bergmann Link: https://patch.msgid.link/20260925130749.4191347-1-arnd@kernel.org Signed-off-by: Johannes Berg --- drivers/net/wireless/broadcom/b43legacy/main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/broadcom/b43legacy/main.c b/drivers/net/wireless/broadcom/b43legacy/main.c index 6b3e0b2bbca7..dfff3710dea3 100644 --- a/drivers/net/wireless/broadcom/b43legacy/main.c +++ b/drivers/net/wireless/broadcom/b43legacy/main.c @@ -3207,7 +3207,8 @@ static void b43legacy_wireless_core_exit(struct b43legacy_wldev *dev) ssb_bus_may_powerdown(dev->dev->bus); } -static void prepare_phy_data_for_init(struct b43legacy_wldev *dev) +static noinline_for_stack void +prepare_phy_data_for_init(struct b43legacy_wldev *dev) { struct b43legacy_phy *phy = &dev->phy; int i;