Re: [PATCH v3 4/6] staging: r8188eu: add error handling of rtw_read16

Pavel Skripkin
2021-08-26T10:58:35Z

On 8/26/21 1:50 PM, Greg KH wrote:
> On Tue, Aug 24, 2021 at 10:27:35AM +0300, Pavel Skripkin wrote:
>> _rtw_read16 function can fail in case of usb transfer failure. But
>> previous function prototype wasn't designed to return an error to
>> caller. It can cause a lot uninit value bugs all across the driver code,
>> since rtw_read16() returns local stack variable to caller.
>>
>> Fix it by changing the prototype of this function. Now it returns an
>> int: 0 on success, negative error value on failure and callers should pass
>> the pointer to storage location for register value.
>>
>> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
>> ---
>> drivers/staging/r8188eu/core/rtw_debug.c | 7 +++-
>> drivers/staging/r8188eu/core/rtw_io.c | 9 ++---
>> drivers/staging/r8188eu/core/rtw_mp_ioctl.c | 4 +-
>> drivers/staging/r8188eu/hal/odm_interface.c | 4 +-
>> .../staging/r8188eu/hal/rtl8188e_hal_init.c | 29 +++++++++++----
>> drivers/staging/r8188eu/hal/rtl8188e_phycfg.c | 5 ++-
>> drivers/staging/r8188eu/hal/usb_halinit.c | 37 ++++++++++++++++---
>> drivers/staging/r8188eu/hal/usb_ops_linux.c | 22 +++++++++--
>> .../staging/r8188eu/include/odm_interface.h | 2 +-
>> drivers/staging/r8188eu/include/rtw_io.h | 6 +--
>> drivers/staging/r8188eu/os_dep/ioctl_linux.c | 28 +++++++++++---
>> 11 files changed, 115 insertions(+), 38 deletions(-)
>>
>> diff --git a/drivers/staging/r8188eu/core/rtw_debug.c b/drivers/staging/r8188eu/core/rtw_debug.c
>> index 8b7d3eb12bd0..a41675e101ac 100644
>> --- a/drivers/staging/r8188eu/core/rtw_debug.c
>> +++ b/drivers/staging/r8188eu/core/rtw_debug.c
>> @@ -91,7 +91,12 @@ int proc_get_read_reg(char *page, char **start,
>> proc_get_read_addr, (u8) tmp);
>> break;
>> case 2:
>> - len += snprintf(page + len, count - len, "rtw_read16(0x%x)=0x%x\n", proc_get_read_addr, rtw_read16(padapter, proc_get_read_addr));
>> + error = rtw_read16(padapter, proc_get_read_addr, (u16 *) &tmp);
>> + if (error)
>> + return len;
>> +
>> + len += snprintf(page + len, count - len, "rtw_read16(0x%x)=0x%x\n",
>> + proc_get_read_addr, (u16) tmp);
>> break;
>> case 4:
>> len += snprintf(page + len, count - len, "rtw_read32(0x%x)=0x%x\n", proc_get_read_addr, rtw_read32(padapter, proc_get_read_addr));
>> diff --git a/drivers/staging/r8188eu/core/rtw_io.c b/drivers/staging/r8188eu/core/rtw_io.c
>> index 2714506c8ffb..fd64893c778d 100644
>> --- a/drivers/staging/r8188eu/core/rtw_io.c
>> +++ b/drivers/staging/r8188eu/core/rtw_io.c
>> @@ -45,18 +45,15 @@ int __must_check _rtw_read8(struct adapter *adapter, u32 addr, u8 *data)
>> return _read8(pintfhdl, addr, data);
>> }
>>
>> -u16 _rtw_read16(struct adapter *adapter, u32 addr)
>> +int __must_check _rtw_read16(struct adapter *adapter, u32 addr, u16 *data)
>> {
>> - u16 r_val;
>> struct io_priv *pio_priv = &adapter->iopriv;
>> struct intf_hdl *pintfhdl = &pio_priv->intf;
>> - u16 (*_read16)(struct intf_hdl *pintfhdl, u32 addr);
>> + int (*_read16)(struct intf_hdl *pintfhdl, u32 addr, u16 *data);
>>
>> _read16 = pintfhdl->io_ops._read16;
>
> Why do you need this extra pointer abstraction anyway? Please unwind
> that first, which will make this function go away (or get easier to
> understand at the least...)
>
It was there before my changes :) I had a plan to clean up DBG macros
and this abstraction after adding error handling...

If you feel, that these clean up are needed before error handling, I can
add them to this series :) Anyway, some of them are already in my local
tree

With regards,
Pavel Skripkin