Hi Peter, Thanks for your review On 31/10/16 13:55, Peter Rosin wrote: > On 2016-10-26 10:53, Lee Jones wrote: >> On Tue, 25 Oct 2016, Kieran Bingham wrote: >> >>> If a user provides a shortened string to match a device to the sysfs i2c >>> interface it will match on the first string that contains that string >>> prefix. >>> >>> for example: >>> echo a 0x68 > /sys/bus/i2c/devices/i2c-2/new_device >>> >>> will match as3711, as3722, and ak8975 incorrectly. >>> >>> Signed-off-by: Kieran Bingham <kieran@xxxxxxxxxxx> >> >> Acked-by: Lee Jones <lee.jones@xxxxxxxxxx> >> >>> --- >>> drivers/i2c/i2c-core.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c >>> index 01bce56f733a..50c9cfdb87b7 100644 >>> --- a/drivers/i2c/i2c-core.c >>> +++ b/drivers/i2c/i2c-core.c >>> @@ -1708,7 +1708,7 @@ i2c_of_match_device_strip_vendor(const struct of_device_id *matches, >>> else >>> name++; >>> >>> - if (!strncasecmp(client->name, name, strlen(client->name))) >>> + if (!strncasecmp(client->name, name, strlen(name))) >>> return matches; >>> } >>> >> > > Is that really so much better? My original thought was that it verifies 'more' of the userspace input. but... > With this patch > echo as3711CRAP 0x68 > /sys/... > will match as3711. > > What if there is some as37112 driver that is the real target? You're right - It looks like the only way to do this correctly is to match the strncasecmp and the strlen of both strings. So really we should be using sysfs_streq(). The only limitation there is that this original code was performing a case-insensitive compare. Lee - Where did the requirement for case insensitive matching come from in your original code. Is it expected to be case-insensitive from the I2C sysfs interface? or are dt-nodes expected to be case-sensitive? Does anyone see reason that this shouldn't be using sysfs_streq()? or do we need a sysfs_strcaseeq()... > Cheers, > Peter > -- Regards Kieran Bingham -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
