syslog: use defined constants instead of raw numbers

Right now the syslog "type" action are just raw numbers which makes
the source difficult to follow.  This patch replaces the raw numbers
with defined constants for some level of sanity.

Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 19 insertions, 26 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index 809cf9a258a0..3e162d867098 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -259,21 +259,6 @@ static inline void boot_delay_msec(void)
 }
 #endif
 
-/*
- * Commands to do_syslog:
- *
- *      0 -- Close the log.  Currently a NOP.
- *      1 -- Open the log. Currently a NOP.
- *      2 -- Read from the log.
- *      3 -- Read all messages remaining in the ring buffer.
- *      4 -- Read and clear all messages remaining in the ring buffer
- *      5 -- Clear ring buffer.
- *      6 -- Disable printk's to console
- *      7 -- Enable printk's to console
- *      8 -- Set level of messages printed to console
- *      9 -- Return number of unread characters in the log buffer
- *     10 -- Return size of the log buffer
- */
 int do_syslog(int type, char __user *buf, int len, bool from_file)
 {
         unsigned i, j, limit, count;
@@ -286,11 +271,11 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
                 return error;
 
         switch (type) {
-        case 0:         /* Close log */
+        case SYSLOG_ACTION_CLOSE:       /* Close log */
                 break;
-        case 1:         /* Open log */
+        case SYSLOG_ACTION_OPEN:        /* Open log */
                 break;
-        case 2:         /* Read from log */
+        case SYSLOG_ACTION_READ:        /* Read from log */
                 error = -EINVAL;
                 if (!buf || len < 0)
                         goto out;
@@ -321,10 +306,12 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
                 if (!error)
                         error = i;
                 break;
-        case 4:         /* Read/clear last kernel messages */
+        /* Read/clear last kernel messages */
+        case SYSLOG_ACTION_READ_CLEAR:
                 do_clear = 1;
                 /* FALL THRU */
-        case 3:         /* Read last kernel messages */
+        /* Read last kernel messages */
+        case SYSLOG_ACTION_READ_ALL:
                 error = -EINVAL;
                 if (!buf || len < 0)
                         goto out;
@@ -377,21 +364,25 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
                         }
                 }
                 break;
-        case 5:         /* Clear ring buffer */
+        /* Clear ring buffer */
+        case SYSLOG_ACTION_CLEAR:
                 logged_chars = 0;
                 break;
-        case 6:         /* Disable logging to console */
+        /* Disable logging to console */
+        case SYSLOG_ACTION_CONSOLE_OFF:
                 if (saved_console_loglevel == -1)
                         saved_console_loglevel = console_loglevel;
                 console_loglevel = minimum_console_loglevel;
                 break;
-        case 7:         /* Enable logging to console */
+        /* Enable logging to console */
+        case SYSLOG_ACTION_CONSOLE_ON:
                 if (saved_console_loglevel != -1) {
                         console_loglevel = saved_console_loglevel;
                         saved_console_loglevel = -1;
                 }
                 break;
-        case 8:         /* Set level of messages printed to console */
+        /* Set level of messages printed to console */
+        case SYSLOG_ACTION_CONSOLE_LEVEL:
                 error = -EINVAL;
                 if (len < 1 || len > 8)
                         goto out;
@@ -402,10 +393,12 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
                 saved_console_loglevel = -1;
                 error = 0;
                 break;
-        case 9:         /* Number of chars in the log buffer */
+        /* Number of chars in the log buffer */
+        case SYSLOG_ACTION_SIZE_UNREAD:
                 error = log_end - log_start;
                 break;
-        case 10:        /* Size of the log buffer */
+        /* Size of the log buffer */
+        case SYSLOG_ACTION_SIZE_BUFFER:
                 error = log_buf_len;
                 break;
         default: