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.
Suggested-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.cha...@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
---
Changes since V6:
- Add Andy's Reviewed-by tag
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 28 ++++++++++----------------
1 file changed, 11 insertions(+), 17 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 25c7379ddb0b..dfd3c6f58901 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1414,13 +1414,11 @@ static ssize_t rdtgroup_mode_write(struct
kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
struct rdtgroup *rdtgrp;
- enum rdtgrp_mode mode;
int ret = 0;
+ int user_m;
- /* Valid input requires a trailing newline */
- if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ if (nbytes == 0)
return -EINVAL;
- buf[nbytes - 1] = '\0';
rdtgrp = rdtgroup_kn_lock_live(of->kn);
if (!rdtgrp) {
@@ -1430,29 +1428,25 @@ static ssize_t rdtgroup_mode_write(struct
kernfs_open_file *of,
rdt_last_cmd_clear();
- mode = rdtgrp->mode;
+ user_m = sysfs_match_string(rdt_mode_str, buf);
- if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) ||
- (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) ||
- (!strcmp(buf, "pseudo-locksetup") &&
- mode == RDT_MODE_PSEUDO_LOCKSETUP) ||
- (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED))
+ /* Do nothing and return success if user asks for current mode */
+ if (user_m == rdtgrp->mode)
goto out;
- if (mode == RDT_MODE_PSEUDO_LOCKED) {
+ if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
rdt_last_cmd_puts("Cannot change pseudo-locked group\n");
ret = -EINVAL;
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;
- } else if (!strcmp(buf, "exclusive")) {
+ } else if (user_m == RDT_MODE_EXCLUSIVE) {
if (!rdtgroup_mode_test_exclusive(rdtgrp)) {
ret = -EINVAL;
goto out;
@@ -1462,16 +1456,16 @@ static ssize_t rdtgroup_mode_write(struct
kernfs_open_file *of,
if (ret)
goto out;
}
- rdtgrp->mode = RDT_MODE_EXCLUSIVE;
- } else if (!strcmp(buf, "pseudo-locksetup")) {
+ } else if (user_m == RDT_MODE_PSEUDO_LOCKSETUP) {
ret = rdtgroup_locksetup_enter(rdtgrp);
if (ret)
goto out;
- rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP;
} else {
rdt_last_cmd_puts("Unknown or unsupported mode\n");
ret = -EINVAL;
+ goto out;
}
+ rdtgrp->mode = user_m;
out:
rdtgroup_kn_unlock(of->kn);
--
2.26.2
