[S390] dasd: use vmalloc for statistics input buffer

The size of the buffer that is used to store DASD statistics input
strings depends on the user input. If the input string is to large,
the write operation could fail with -ENOMEM. To avoid this, use
vmalloc instead of kmalloc.

Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 432444af7ee47b0192e08bddaee479e601c5c350..a1d3ddba99ccad4b90d4a9a06af1fd371b2d0033 100644 (file)
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -24,6 +24,7 @@
 #include <linux/mutex.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
+#include <linux/vmalloc.h>
 
 #include <asm/ccwdev.h>
 #include <asm/ebcdic.h>
@@ -888,11 +889,11 @@ char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 {
        char *buffer;
 
-       buffer = kmalloc(user_len + 1, GFP_KERNEL);
+       buffer = vmalloc(user_len + 1);
        if (buffer == NULL)
                return ERR_PTR(-ENOMEM);
        if (copy_from_user(buffer, user_buf, user_len) != 0) {
-               kfree(buffer);
+               vfree(buffer);
                return ERR_PTR(-EFAULT);
        }
        /* got the string, now strip linefeed. */
@@ -930,7 +931,7 @@ static ssize_t dasd_stats_write(struct file *file,
                dasd_profile_off(prof);
        } else
                rc = -EINVAL;
-       kfree(buffer);
+       vfree(buffer);
        return rc;
 }
 
@@ -1042,7 +1043,7 @@ static ssize_t dasd_stats_global_write(struct file *file,
                dasd_global_profile_level = DASD_PROFILE_OFF;
        } else
                rc = -EINVAL;
-       kfree(buffer);
+       vfree(buffer);
        return rc;
 }
 

diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c
index 6c3c5364d0824426cf4a7db5db7bd588804ebbc5..e12989fff4ffca7f394124a814a176b82985b941 100644 (file)
--- a/drivers/s390/block/dasd_proc.c
+++ b/drivers/s390/block/dasd_proc.c
@@ -312,14 +312,14 @@ static ssize_t dasd_stats_proc_write(struct file *file,
                pr_info("The statistics have been reset\n");
        } else
                goto out_parse_error;
-       kfree(buffer);
+       vfree(buffer);
        return user_len;
 out_parse_error:
        rc = -EINVAL;
        pr_warning("%s is not a supported value for /proc/dasd/statistics\n",
                str);
 out_error:
-       kfree(buffer);
+       vfree(buffer);
        return rc;
 #else
        pr_warning("/proc/dasd/statistics: is not activated in this kernel\n");