linux-kernel - [PATCH v2 1/6] cpufreq/amd-pstate: Use sysfs_match

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20251009161756.2728199-2-superm1@kernel.org>
Date: Thu,  9 Oct 2025 11:17:51 -0500
From: "Mario Limonciello (AMD)" <superm1@...nel.org>
To: "Gautham R . Shenoy" <gautham.shenoy@....com>
Cc: Perry Yuan <perry.yuan@....com>,
	linux-kernel@...r.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	linux-pm@...r.kernel.org (open list:CPU FREQUENCY SCALING FRAMEWORK),
	"Mario Limonciello (AMD)" <superm1@...nel.org>
Subject: [PATCH v2 1/6] cpufreq/amd-pstate: Use sysfs_match_string() for epp

Rather than scanning the buffer and manually matching the string
use the sysfs macros.

Signed-off-by: Mario Limonciello (AMD) <superm1@...nel.org>
---
v2:
 * Drop NULL from energy_perf_strings too (Gautham)
---
 drivers/cpufreq/amd-pstate.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index b44f0f7a5ba1c..0bc5013448873 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -118,7 +118,6 @@ static const char * const energy_perf_strings[] = {
 	[EPP_INDEX_BALANCE_PERFORMANCE] = "balance_performance",
 	[EPP_INDEX_BALANCE_POWERSAVE] = "balance_power",
 	[EPP_INDEX_POWERSAVE] = "power",
-	NULL
 };
 
 static unsigned int epp_values[] = {
@@ -1137,16 +1136,15 @@ static ssize_t show_amd_pstate_hw_prefcore(struct cpufreq_policy *policy,
 static ssize_t show_energy_performance_available_preferences(
 				struct cpufreq_policy *policy, char *buf)
 {
-	int i = 0;
-	int offset = 0;
+	int offset = 0, i;
 	struct amd_cpudata *cpudata = policy->driver_data;
 
 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
 		return sysfs_emit_at(buf, offset, "%s\n",
 				energy_perf_strings[EPP_INDEX_PERFORMANCE]);
 
-	while (energy_perf_strings[i] != NULL)
-		offset += sysfs_emit_at(buf, offset, "%s ", energy_perf_strings[i++]);
+	for (i = 0; i < ARRAY_SIZE(energy_perf_strings); i++)
+		offset += sysfs_emit_at(buf, offset, "%s ", energy_perf_strings[i]);
 
 	offset += sysfs_emit_at(buf, offset, "\n");
 
@@ -1157,15 +1155,10 @@ static ssize_t store_energy_performance_preference(
 		struct cpufreq_policy *policy, const char *buf, size_t count)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
-	char str_preference[21];
 	ssize_t ret;
 	u8 epp;
 
-	ret = sscanf(buf, "%20s", str_preference);
-	if (ret != 1)
-		return -EINVAL;
-
-	ret = match_string(energy_perf_strings, -1, str_preference);
+	ret = sysfs_match_string(energy_perf_strings, buf);
 	if (ret < 0)
 		return -EINVAL;
 
-- 
2.43.0