Re: [PATCH V4 4/4] x86/resctrl: Use appropriate API for strings terminated by newline
From: Andy Shevchenko
Date: Mon May 18 2020 - 07:50:28 EST
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...
> 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;
?
> out:
Note, I didn't check all branches carefully.
--
With Best Regards,
Andy Shevchenko