回复: [PATCH] tty: 8250: replace snprintf in show functions with sysfs_emit
From: 王擎
Date: Fri Oct 15 2021 - 03:14:04 EST
>> show() must not use snprintf() when formatting the value to be
>> returned to user space.
>
>Why must it not? What is broken in the existing code?
Replyed in another email.
>
>>
>> Fix the coccicheck warnings:
>> WARNING: use scnprintf or sprintf.
>>
>> Signed-off-by: Qing Wang <wangqing@xxxxxxxx>
>> ---
>> drivers/tty/serial/8250/8250_aspeed_vuart.c | 6 +++---
>> drivers/tty/serial/8250/8250_port.c | 2 +-
>> 2 files changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
>> index 2350fb3..082b9bd 100644
>> --- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
>> +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
>> @@ -82,7 +82,7 @@ static ssize_t lpc_address_show(struct device *dev,
>> addr = (aspeed_vuart_readb(vuart, ASPEED_VUART_ADDRH) << 8) |
>> (aspeed_vuart_readb(vuart, ASPEED_VUART_ADDRL));
>>
>> - return snprintf(buf, PAGE_SIZE - 1, "0x%x\n", addr);
>> + return sysfs_emit(buf - 1, "0x%x\n", addr);
>
>what is the buf-1 thing here for?
>
>Doing a tree-wide change for this type of thing might not be wanted by
>many maintainers, especially if you introduce bugs like this :(
Sorry for this, my tool needs to be optimized.
Please ignore this patch.
Thanks,
Qing
>
>greg k-h
>