[PATCH 6.18 304/752] scsi: buslogic: Reduce stack usage

Sasha Levin
2026-02-28T17:52:22Z

From: Arnd Bergmann <arnd@arndb.de>

[ Upstream commit e17f0d4cc006265dd92129db4bf9da3a2e4a4f66 ]

Some randconfig builds run into excessive stack usage with gcc-14 or
higher, which use __attribute__((cold)) where earlier versions did not do
that:

drivers/scsi/BusLogic.c: In function 'blogic_init':
drivers/scsi/BusLogic.c:2398:1: error: the frame size of 1680 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]

The problem is that a lot of code gets inlined into blogic_init() here. Two
functions stick out, but they are a bit different:

- blogic_init_probeinfo_list() actually uses a few hundred bytes of kernel
stack, which is a problem in combination with other functions that also
do. Marking this one as noinline means that the stack slots get get
reused between function calls

- blogic_reportconfig() has a few large variables, but whenever it is not
inlined into its caller, the compiler is actually smart enough to reuse
stack slots for these automatically, so marking it as noinline saves
most of the stack space by itself.

The combination of both of these should avoid the problem entirely.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260203163321.2598593-1-arnd@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/BusLogic.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
index a86d780d1ba40..026c3e617cb1c 100644
--- a/drivers/scsi/BusLogic.c
+++ b/drivers/scsi/BusLogic.c
@@ -920,7 +920,8 @@ static int __init blogic_init_fp_probeinfo(struct blogic_adapter *adapter)
a particular probe order.
*/

-static void __init blogic_init_probeinfo_list(struct blogic_adapter *adapter)
+static noinline_for_stack void __init
+blogic_init_probeinfo_list(struct blogic_adapter *adapter)
{
/*
If a PCI BIOS is present, interrogate it for MultiMaster and
@@ -1690,7 +1691,8 @@ static bool __init blogic_rdconfig(struct blogic_adapter *adapter)
blogic_reportconfig reports the configuration of Host Adapter.
*/

-static bool __init blogic_reportconfig(struct blogic_adapter *adapter)
+static noinline_for_stack bool __init
+blogic_reportconfig(struct blogic_adapter *adapter)
{
unsigned short alltgt_mask = (1 << adapter->maxdev) - 1;
unsigned short sync_ok, fast_ok;
--
2.51.0