Hi Andy,
On 5/18/2020 9:06 AM, Reinette Chatre wrote:
> On 5/18/2020 4:50 AM, Andy Shevchenko wrote:
>> On Sat, May 16, 2020 at 11:28:41AM -0700, Reinette Chatre wrote:
>>> The user input to files in the resctrl filesystem are expected to be
>>> terminated with a newline. Testing the user input includes a test for
>>> the presence of a newline and then replacing the newline with NUL
>>> byte followed by comparison using strcmp().
>>>
>>> sysfs_streq() exists to test if strings are equal, treating both NUL and
>>> newline-then-NUL as equivalent string terminations. Even more,
>>> sysfs_match_string() exists to match a given string in an array using
>>> sysfs_streq().
>>>
>>> Replace existing strcmp() comparisons of strings that are terminated
>>> with a newline with more appropriate sysfs_streq() via the
>>> sysfs_match_string() API that can perform the match across the different
>>> mode strings that are already maintained in an array.
>>
>> Sorry for late comment, but just have noticed...
>
> No problem. I do appreciate your feedback because it helps me to improve
> the code.
>
>>
>>> if (mode == RDT_MODE_PSEUDO_LOCKED) {
>>> @@ -1445,14 +1450,14 @@ static ssize_t rdtgroup_mode_write(struct
>>> kernfs_open_file *of,
>>> goto out;
>>> }
>>>
>>> - if (!strcmp(buf, "shareable")) {
>>> + if (user_m == RDT_MODE_SHAREABLE) {
>>> if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
>>> ret = rdtgroup_locksetup_exit(rdtgrp);
>>> if (ret)
>>> goto out;
>>> }
>>
>>> rdtgrp->mode = RDT_MODE_SHAREABLE;
>>
>> ...can we simple move this and similar (in other branches) to...
>>
>>
>>> - } else {
>>> - rdt_last_cmd_puts("Unknown or unsupported mode\n");
>>> - ret = -EINVAL;
>>> }
>>
>> ...here as
>>
>> rdtgrp->mode = user_m;
>
> Will do.
Actually ... now that I take a closer look, this would let an invalid
mode change (RDT_MODE_PSEUDO_LOCKED) slip through so I plan to keep this
code as is.
> It also looks like the only reason for the "mode" local variable was to
> make those earlier "strcmp" lines shorter. With those long lines removed
> in this patch this local variable is no longer needed and I will remove
> it also.
I will still do this.
Reinette
