On Wed, Nov 29, 2023 at 5:06 AM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Toubling the number of PHYs also doubled the stack usage of this function,
> exceeding the 32-bit limit of 1024 bytes:
>
> drivers/scsi/mpi3mr/mpi3mr_transport.c: In function 'mpi3mr_refresh_sas_ports':
> drivers/scsi/mpi3mr/mpi3mr_transport.c:1818:1: error: the frame size of 1636 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
>
> Since the sas_io_unit_pg0 structure is already allocated dynamically, use
> the same method here. The size of the allocation can be smaller based on the
> actual number of phys now, so use this as an upper bound.
>
> Fixes: cb5b60894602 ("scsi: mpi3mr: Increase maximum number of PHYs to 64 from 32")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/scsi/mpi3mr/mpi3mr_transport.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/mpi3mr/mpi3mr_transport.c b/drivers/scsi/mpi3mr/mpi3mr_transport.c
> index c0c8ab586957..ab04596dbdf5 100644
> --- a/drivers/scsi/mpi3mr/mpi3mr_transport.c
> +++ b/drivers/scsi/mpi3mr/mpi3mr_transport.c
> @@ -1671,7 +1671,7 @@ mpi3mr_update_mr_sas_port(struct mpi3mr_ioc *mrioc, struct host_port *h_port,
> void
> mpi3mr_refresh_sas_ports(struct mpi3mr_ioc *mrioc)
> {
> - struct host_port h_port[64];
> + struct host_port *h_port = NULL;
> int i, j, found, host_port_count = 0, port_idx;
> u16 sz, attached_handle, ioc_status;
> struct mpi3_sas_io_unit_page0 *sas_io_unit_pg0 = NULL;
> @@ -1685,6 +1685,11 @@ mpi3mr_refresh_sas_ports(struct mpi3mr_ioc *mrioc)
> sas_io_unit_pg0 = kzalloc(sz, GFP_KERNEL);
> if (!sas_io_unit_pg0)
> return;
> + h_port = kcalloc(mrioc->sas_hba.num_phys, sizeof(struct host_port),
> + GFP_KERNEL);
>> We need more than sas_hba.num_phys, so can you please use 64 instead of sas_hba.num_phys. Otherwise looks good.
> + if (!h_port)
> + goto out;
> +
> if (mpi3mr_cfg_get_sas_io_unit_pg0(mrioc, sas_io_unit_pg0, sz)) {
> ioc_err(mrioc, "failure at %s:%d/%s()!\n",
> __FILE__, __LINE__, __func__);
> @@ -1814,6 +1819,7 @@ mpi3mr_refresh_sas_ports(struct mpi3mr_ioc *mrioc)
> }
> }
> out:
> + kfree(h_port);
> kfree(sas_io_unit_pg0);
> }
>
> --
> 2.39.2
>
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