Re: [RFC PATCH] cw1200: use kmalloc() allocation instead of stack

From: Ulf Hansson
Date: Wed Jun 30 2021 - 06:04:02 EST

On Tue, 22 Jun 2021 at 22:23, Jernej Skrabec <jernej.skrabec@xxxxxxxxx> wrote:
>
> It turns out that if CONFIG_VMAP_STACK is enabled and src or dst is
> memory allocated on stack, SDIO operations fail due to invalid memory
> address conversion:
>
> cw1200_wlan_sdio: Probe called
> sunxi-mmc 4021000.mmc: DMA addr 0x0000800051eab954+4 overflow (mask ffffffff, bus limit 0).
> WARNING: CPU: 2 PID: 152 at kernel/dma/direct.h:97 dma_direct_map_sg+0x26c/0x28c
> CPU: 2 PID: 152 Comm: kworker/2:2 Not tainted 5.13.0-rc1-00026-g84114ef026b9-dirty #85
> Hardware name: X96 Mate (DT)
> Workqueue: events_freezable mmc_rescan
> pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--)
> pc : dma_direct_map_sg+0x26c/0x28c
> lr : dma_direct_map_sg+0x26c/0x28c
> sp : ffff800011eab540
> x29: ffff800011eab540 x28: ffff800011eab738 x27: 0000000000000000
> x26: ffff000001daf010 x25: 0000000000000000 x24: 0000000000000000
> x23: 0000000000000002 x22: fffffc0000000000 x21: ffff8000113b0ab0
> x20: ffff80001181abb0 x19: 0000000000000001 x18: ffffffffffffffff
> x17: 00000000fa97f83f x16: 00000000d2e01bf8 x15: ffff8000117ffb1d
> x14: ffffffffffffffff x13: ffff8000117ffb18 x12: fffffffffffc593f
> x11: ffff800011676ad0 x10: fffffffffffe0000 x9 : ffff800011eab540
> x8 : 206b73616d282077 x7 : 000000000000000f x6 : 000000000000000c
> x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000ffffffff
> x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff00000283b800
> Call trace:
> dma_direct_map_sg+0x26c/0x28c
> dma_map_sg_attrs+0x2c/0x60
> sunxi_mmc_request+0x70/0x420
> __mmc_start_request+0x68/0x134
> mmc_start_request+0x84/0xac
> mmc_wait_for_req+0x70/0x100
> mmc_io_rw_extended+0x1cc/0x2c0
> sdio_io_rw_ext_helper+0x194/0x240
> sdio_memcpy_fromio+0x20/0x2c
> cw1200_sdio_memcpy_fromio+0x20/0x2c
> __cw1200_reg_read+0x34/0x60
> cw1200_reg_read+0x48/0x70
> cw1200_load_firmware+0x38/0x5d0
> cw1200_core_probe+0x794/0x970
> cw1200_sdio_probe+0x124/0x22c
> sdio_bus_probe+0xe8/0x1d0
> really_probe+0xe4/0x504
> driver_probe_device+0x64/0xcc
> __device_attach_driver+0xd0/0x14c
> bus_for_each_drv+0x78/0xd0
> __device_attach+0xdc/0x184
> device_initial_probe+0x14/0x20
> bus_probe_device+0x9c/0xa4
> device_add+0x350/0x83c
> sdio_add_func+0x6c/0x90
> mmc_attach_sdio+0x1b0/0x430
> mmc_rescan+0x254/0x2e0
> process_one_work+0x1d0/0x34c
> worker_thread+0x13c/0x470
> kthread+0x154/0x160
> ret_from_fork+0x10/0x34
> sunxi-mmc 4021000.mmc: dma_map_sg failed
> sunxi-mmc 4021000.mmc: map DMA failed
> Can't read config register.
>
> Fix that by using kmalloc() allocated memory for read/write 16/32
> funtions.
>
> Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>

Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>

Kind regards
Uffe

> ---
> drivers/net/wireless/st/cw1200/hwio.c | 52 +++++++++++++++++++++------
> drivers/net/wireless/st/cw1200/hwio.h | 51 ++++++++++++++++++++------
> 2 files changed, 83 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/net/wireless/st/cw1200/hwio.c b/drivers/net/wireless/st/cw1200/hwio.c
> index 3ba462de8e91..5521cb7f2233 100644
> --- a/drivers/net/wireless/st/cw1200/hwio.c
> +++ b/drivers/net/wireless/st/cw1200/hwio.c
> @@ -66,33 +66,65 @@ static int __cw1200_reg_write(struct cw1200_common *priv, u16 addr,
> static inline int __cw1200_reg_read_32(struct cw1200_common *priv,
> u16 addr, u32 *val)
> {
> - __le32 tmp;
> - int i = __cw1200_reg_read(priv, addr, &tmp, sizeof(tmp), 0);
> - *val = le32_to_cpu(tmp);
> + __le32 *tmp;
> + int i;
> +
> + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
> + if (!tmp)
> + return -ENOMEM;
> +
> + i = __cw1200_reg_read(priv, addr, tmp, sizeof(*tmp), 0);
> + *val = le32_to_cpu(*tmp);
> + kfree(tmp);
> return i;
> }
>
> static inline int __cw1200_reg_write_32(struct cw1200_common *priv,
> u16 addr, u32 val)
> {
> - __le32 tmp = cpu_to_le32(val);
> - return __cw1200_reg_write(priv, addr, &tmp, sizeof(tmp), 0);
> + __le32 *tmp;
> + int i;
> +
> + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
> + if (!tmp)
> + return -ENOMEM;
> +
> + *tmp = cpu_to_le32(val);
> + i = __cw1200_reg_write(priv, addr, tmp, sizeof(*tmp), 0);
> + kfree(tmp);
> + return i;
> }
>
> static inline int __cw1200_reg_read_16(struct cw1200_common *priv,
> u16 addr, u16 *val)
> {
> - __le16 tmp;
> - int i = __cw1200_reg_read(priv, addr, &tmp, sizeof(tmp), 0);
> - *val = le16_to_cpu(tmp);
> + __le16 *tmp;
> + int i;
> +
> + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
> + if (!tmp)
> + return -ENOMEM;
> +
> + i = __cw1200_reg_read(priv, addr, tmp, sizeof(*tmp), 0);
> + *val = le16_to_cpu(*tmp);
> + kfree(tmp);
> return i;
> }
>
> static inline int __cw1200_reg_write_16(struct cw1200_common *priv,
> u16 addr, u16 val)
> {
> - __le16 tmp = cpu_to_le16(val);
> - return __cw1200_reg_write(priv, addr, &tmp, sizeof(tmp), 0);
> + __le16 *tmp;
> + int i;
> +
> + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
> + if (!tmp)
> + return -ENOMEM;
> +
> + *tmp = cpu_to_le16(val);
> + i = __cw1200_reg_write(priv, addr, tmp, sizeof(*tmp), 0);
> + kfree(tmp);
> + return i;
> }
>
> int cw1200_reg_read(struct cw1200_common *priv, u16 addr, void *buf,
> diff --git a/drivers/net/wireless/st/cw1200/hwio.h b/drivers/net/wireless/st/cw1200/hwio.h
> index d1e629a566c2..088d2a1bacc0 100644
> --- a/drivers/net/wireless/st/cw1200/hwio.h
> +++ b/drivers/net/wireless/st/cw1200/hwio.h
> @@ -166,34 +166,65 @@ int cw1200_reg_write(struct cw1200_common *priv, u16 addr,
> static inline int cw1200_reg_read_16(struct cw1200_common *priv,
> u16 addr, u16 *val)
> {
> - __le32 tmp;
> + __le32 *tmp;
> int i;
> - i = cw1200_reg_read(priv, addr, &tmp, sizeof(tmp));
> - *val = le32_to_cpu(tmp) & 0xfffff;
> +
> + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
> + if (!tmp)
> + return -ENOMEM;
> +
> + i = cw1200_reg_read(priv, addr, tmp, sizeof(*tmp));
> + *val = le32_to_cpu(*tmp) & 0xfffff;
> + kfree(tmp);
> return i;
> }
>
> static inline int cw1200_reg_write_16(struct cw1200_common *priv,
> u16 addr, u16 val)
> {
> - __le32 tmp = cpu_to_le32((u32)val);
> - return cw1200_reg_write(priv, addr, &tmp, sizeof(tmp));
> + __le32 *tmp;
> + int i;
> +
> + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
> + if (!tmp)
> + return -ENOMEM;
> +
> + *tmp = cpu_to_le32((u32)val);
> + i = cw1200_reg_write(priv, addr, tmp, sizeof(*tmp));
> + kfree(tmp);
> + return i;
> }
>
> static inline int cw1200_reg_read_32(struct cw1200_common *priv,
> u16 addr, u32 *val)
> {
> - __le32 tmp;
> - int i = cw1200_reg_read(priv, addr, &tmp, sizeof(tmp));
> - *val = le32_to_cpu(tmp);
> + __le32 *tmp;
> + int i;
> +
> + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
> + if (!tmp)
> + return -ENOMEM;
> +
> + i = cw1200_reg_read(priv, addr, tmp, sizeof(*tmp));
> + *val = le32_to_cpu(*tmp);
> + kfree(tmp);
> return i;
> }
>
> static inline int cw1200_reg_write_32(struct cw1200_common *priv,
> u16 addr, u32 val)
> {
> - __le32 tmp = cpu_to_le32(val);
> - return cw1200_reg_write(priv, addr, &tmp, sizeof(val));
> + __le32 *tmp;
> + int i;
> +
> + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
> + if (!tmp)
> + return -ENOMEM;
> +
> + *tmp = cpu_to_le32(val);
> + i = cw1200_reg_write(priv, addr, tmp, sizeof(val));
> + kfree(tmp);
> + return i;
> }
>
> int cw1200_indirect_read(struct cw1200_common *priv, u32 addr, void *buf,
> --
> 2.32.0
>