oprofile, s390: Fix uninitialized memory access when writing to oprofilefs

If oprofilefs_ulong_from_user() is called with count equals zero, *val
remains unchanged. Depending on the implementation it might be
uninitialized. Fixing users of oprofilefs_ulong_ from_user().

We missed these s390 changes with:

 913050b oprofile: Fix uninitialized memory access when writing to writing to oprofilefs

Cc: stable@vger.kernel.org  # 3.3+
Signed-off-by: Robert Richter <robert.richter@amd.com>

diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c
index a1e9d69..584b936 100644 (file)
--- a/arch/s390/oprofile/init.c
+++ b/arch/s390/oprofile/init.c
@@ -169,7 +169,7 @@ static ssize_t hw_interval_write(struct file *file, char const __user *buf,
        if (*offset)
                return -EINVAL;
        retval = oprofilefs_ulong_from_user(&val, buf, count);
-       if (retval)
+       if (retval <= 0)
                return retval;
        if (val < oprofile_min_interval)
                oprofile_hw_interval = oprofile_min_interval;
@@ -212,7 +212,7 @@ static ssize_t hwsampler_zero_write(struct file *file, char const __user *buf,
                return -EINVAL;
 
        retval = oprofilefs_ulong_from_user(&val, buf, count);
-       if (retval)
+       if (retval <= 0)
                return retval;
        if (val != 0)
                return -EINVAL;
@@ -243,7 +243,7 @@ static ssize_t hwsampler_kernel_write(struct file *file, char const __user *buf,
                return -EINVAL;
 
        retval = oprofilefs_ulong_from_user(&val, buf, count);
-       if (retval)
+       if (retval <= 0)
                return retval;
 
        if (val != 0 && val != 1)
@@ -278,7 +278,7 @@ static ssize_t hwsampler_user_write(struct file *file, char const __user *buf,
                return -EINVAL;
 
        retval = oprofilefs_ulong_from_user(&val, buf, count);
-       if (retval)
+       if (retval <= 0)
                return retval;
 
        if (val != 0 && val != 1)
@@ -317,7 +317,7 @@ static ssize_t timer_enabled_write(struct file *file, char const __user *buf,
                return -EINVAL;
 
        retval = oprofilefs_ulong_from_user(&val, buf, count);
-       if (retval)
+       if (retval <= 0)
                return retval;
 
        if (val != 0 && val != 1)