cpufreq / core: Fix printing of governor and driver name

Arrays for governer and driver name are of size CPUFREQ_NAME_LEN or 16.
i.e. 15 bytes for name and 1 for trailing '\0'.

When cpufreq driver print these names (for sysfs), it includes '\n' or ' ' in
the fmt string and still passes length as CPUFREQ_NAME_LEN. If the driver or
governor names are using all 15 fields allocated to them, then the trailing '\n'
or ' ' will never be printed. And so commands like:

root@linaro-developer# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_driver

will print something like:

cpufreq_foodrvroot@linaro-developer#

Fix this by increasing print length by one character.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 021973b7dc569ecf17c4e7019a59f96cef60bee9..db6e337ad3379d9ce1b8868fd5a1bc2e6ae063e2 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -445,7 +445,7 @@ static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf)
        else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
                return sprintf(buf, "performance\n");
        else if (policy->governor)
-               return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n",
+               return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n",
                                policy->governor->name);
        return -EINVAL;
 }
@@ -491,7 +491,7 @@ static ssize_t store_scaling_governor(struct cpufreq_policy *policy,
  */
 static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf)
 {
-       return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
+       return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name);
 }
 
 /**
@@ -512,7 +512,7 @@ static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy,
                if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char))
                    - (CPUFREQ_NAME_LEN + 2)))
                        goto out;
-               i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
+               i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name);
        }
 out:
        i += sprintf(&buf[i], "\n");

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index b60f6ba01d0c787225b626c5f4b4eef2cdca1e37..fc4b78510151bb21b91c10f310b039821e2b9ba9 100644 (file)
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -22,6 +22,8 @@
 #include <asm/div64.h>
 
 #define CPUFREQ_NAME_LEN 16
+/* Print length for names. Extra 1 space for accomodating '\n' in prints */
+#define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
 
 
 /*********************************************************************