On Tue, Jul 09, 2024 at 03:27:37PM +0300, Leon Romanovsky wrote: > On Tue, Jul 09, 2024 at 06:52:42PM +0800, flyingpenghao@xxxxxxxxx wrote: > > From: Peng Hao <flyingpeng@xxxxxxxxxxx> > > > > When building kernel with clang, which will typically > > have sanitizers enabled, there is a warning about a large stack frame. > > > > drivers/infiniband/hw/ocrdma/ocrdma_stats.c:686:16: error: stack frame size (20664) exceeds limit (8192) in 'ocrdma_dbgfs_ops_read' [-Werror,-Wframe-larger-than] > > static ssize_t ocrdma_dbgfs_ops_read(struct file *filp, char __user *buffer, > > ^ > > Please fix it, not hide it. Agreed, this is far from an acceptable solution. No details were provided around compiler, architecture, or configuration, so I can only speculate what is happening here. From reading the code, I suspect that ocrdma_add_stat() is getting inlined into all of its callsites but the stack slot for buff[128] is not getting reused, which may be related to a missing lifetime marker like [1] or sanitizer instrumentation. I am guessing that marking ocrdma_dbgfs_ops_read() as noinline_for_stack would resolve this. static noinline_for_stack int ocrdma_add_stat(char *start, char *pcur, If this is not tolerable for all configurations, it could be made more pointed with something like static #if defined(CONFIG_CC_IS_CLANG) && (defined(CONFIG_KASAN) || defined(CONFIG_KCSAN)) noinline_for_stack #endif int ocrdma_add_stat(char *start, char *pcur, but I am aware that is quite ugly. [1]: https://github.com/llvm/llvm-project/issues/38157#issuecomment-1756321571 Cheers, Nathan > > Increase the frame size by 20% to set. > > > > Signed-off-by: Peng Hao <flyingpeng@xxxxxxxxxxx> > > --- > > drivers/infiniband/hw/ocrdma/Makefile | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/drivers/infiniband/hw/ocrdma/Makefile b/drivers/infiniband/hw/ocrdma/Makefile > > index 14fba95021d8..a1e9fcc04751 100644 > > --- a/drivers/infiniband/hw/ocrdma/Makefile > > +++ b/drivers/infiniband/hw/ocrdma/Makefile > > @@ -3,4 +3,10 @@ ccflags-y := -I $(srctree)/drivers/net/ethernet/emulex/benet > > > > obj-$(CONFIG_INFINIBAND_OCRDMA) += ocrdma.o > > > > +ifneq ($(CONFIG_FRAME_WARN),0) > > +ifeq ($(filter y,$(CONFIG_KASAN)$(CONFIG_KCSAN)),y) > > +CFLAGS_ocrdma_stats.o = -Wframe-larger-than=22664 > > +endif > > +endif > > + > > ocrdma-y := ocrdma_main.o ocrdma_verbs.o ocrdma_hw.o ocrdma_ah.o ocrdma_stats.o > > -- > > 2.27.0 > > > >
