On Wednesday 10 of October 2012 10:12:11 Viresh Kumar wrote:

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

Thanks for the patch, I'll queue it up for v3.8.

Rafael

---

drivers/cpufreq/cpufreq.c | 6 +++--- include/linux/cpufreq.h | 2 ++ 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 021973b..db6e337 100644 --- 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 b60f6ba..fc4b785 100644 --- 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) /*********************************************************************