};
#endif
+enum devkmsg_log_bits {
+ __DEVKMSG_LOG_BIT_ON = 0,
+ __DEVKMSG_LOG_BIT_OFF,
+ __DEVKMSG_LOG_BIT_LOCK,
+};
+
+enum devkmsg_log_masks {
+ DEVKMSG_LOG_MASK_ON = BIT(__DEVKMSG_LOG_BIT_ON),
+ DEVKMSG_LOG_MASK_OFF = BIT(__DEVKMSG_LOG_BIT_OFF),
+ DEVKMSG_LOG_MASK_LOCK = BIT(__DEVKMSG_LOG_BIT_LOCK),
+};
+
+/* Keep both the 'on' and 'off' bits clear, i.e. ratelimit by default: */
+#define DEVKMSG_LOG_MASK_DEFAULT 0
+
+static unsigned int __read_mostly devkmsg_log = DEVKMSG_LOG_MASK_DEFAULT;
+
+static int __control_devkmsg(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (!strncmp(str, "on", 2)) {
+ devkmsg_log = DEVKMSG_LOG_MASK_ON;
+ return 2;
+ } else if (!strncmp(str, "off", 3)) {
+ devkmsg_log = DEVKMSG_LOG_MASK_OFF;
+ return 3;
+ } else if (!strncmp(str, "ratelimit", 9)) {
+ devkmsg_log = DEVKMSG_LOG_MASK_DEFAULT;
+ return 9;
+ }
+ return -EINVAL;
+}
+
+static int __init control_devkmsg(char *str)
+{
+ if (__control_devkmsg(str) < 0)
+ return 1;
+
+ /*
+ * Set sysctl string accordingly:
+ */
+ if (devkmsg_log == DEVKMSG_LOG_MASK_ON) {
+ memset(devkmsg_log_str, 0, DEVKMSG_STR_MAX_SIZE);
+ strncpy(devkmsg_log_str, "on", 2);
+ } else if (devkmsg_log == DEVKMSG_LOG_MASK_OFF) {
+ memset(devkmsg_log_str, 0, DEVKMSG_STR_MAX_SIZE);
+ strncpy(devkmsg_log_str, "off", 3);
+ }
+ /* else "ratelimit" which is set by default. */
+
+ /*
+ * Sysctl cannot change it anymore. The kernel command line setting of
+ * this parameter is to force the setting to be permanent throughout the
+ * runtime of the system. This is a precation measure against userspace
+ * trying to be a smarta** and attempting to change it up on us.
+ */
+ devkmsg_log |= DEVKMSG_LOG_MASK_LOCK;
+
+ return 0;
+}
+__setup("printk.devkmsg=", control_devkmsg);
+
+char devkmsg_log_str[DEVKMSG_STR_MAX_SIZE] = "ratelimit";
+
+int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write,
+ void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+ char old_str[DEVKMSG_STR_MAX_SIZE];
+ unsigned int old;
+ int err;
+
+ if (write) {
+ if (devkmsg_log & DEVKMSG_LOG_MASK_LOCK)
+ return -EINVAL;
+
+ old = devkmsg_log;
+ strncpy(old_str, devkmsg_log_str, DEVKMSG_STR_MAX_SIZE);
+ }
+
+ err = proc_dostring(table, write, buffer, lenp, ppos);
+ if (err)
+ return err;
+
+ if (write) {
+ err = __control_devkmsg(devkmsg_log_str);
+
+ /*
+ * Do not accept an unknown string OR a known string with
+ * trailing crap...
+ */
+ if (err < 0 || (err + 1 != *lenp)) {
+
+ /* ... and restore old setting. */
+ devkmsg_log = old;
+ strncpy(devkmsg_log_str, old_str, DEVKMSG_STR_MAX_SIZE);
+
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
/*
* Number of registered extended console drivers.
*
u64 seq;
u32 idx;
enum log_flags prev;
+ struct ratelimit_state rs;
struct mutex lock;
char buf[CONSOLE_EXT_LOG_MAX];
};
char *buf, *line;
int level = default_message_loglevel;
int facility = 1; /* LOG_USER */
+ struct file *file = iocb->ki_filp;
+ struct devkmsg_user *user = file->private_data;
size_t len = iov_iter_count(from);
ssize_t ret = len;
- if (len > LOG_LINE_MAX)
+ if (!user || len > LOG_LINE_MAX)
return -EINVAL;
+
+ /* Ignore when user logging is disabled. */
+ if (devkmsg_log & DEVKMSG_LOG_MASK_OFF)
+ return len;
+
+ /* Ratelimit when not explicitly enabled. */
+ if (!(devkmsg_log & DEVKMSG_LOG_MASK_ON)) {
+ if (!___ratelimit(&user->rs, current->comm))
+ return ret;
+ }
+
buf = kmalloc(len+1, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
struct devkmsg_user *user;
int err;
- /* write-only does not need any file context */
- if ((file->f_flags & O_ACCMODE) == O_WRONLY)
- return 0;
+ if (devkmsg_log & DEVKMSG_LOG_MASK_OFF)
+ return -EPERM;
- err = check_syslog_permissions(SYSLOG_ACTION_READ_ALL,
- SYSLOG_FROM_READER);
- if (err)
- return err;
+ /* write-only does not need any file context */
+ if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
+ err = check_syslog_permissions(SYSLOG_ACTION_READ_ALL,
+ SYSLOG_FROM_READER);
+ if (err)
+ return err;
+ }
user = kmalloc(sizeof(struct devkmsg_user), GFP_KERNEL);
if (!user)
return -ENOMEM;
+ ratelimit_default_init(&user->rs);
+ ratelimit_set_flags(&user->rs, RATELIMIT_MSG_ON_RELEASE);
+
mutex_init(&user->lock);
raw_spin_lock_irq(&logbuf_lock);
if (!user)
return 0;
+ ratelimit_state_exit(&user->rs);
+
mutex_destroy(&user->lock);
kfree(user);
return 0;
}
EXPORT_SYMBOL(printk_emit);
-#ifdef CONFIG_PRINTK
-#define define_pr_level(func, loglevel) \
-asmlinkage __visible void func(const char *fmt, ...) \
-{ \
- va_list args; \
- \
- va_start(args, fmt); \
- vprintk_default(loglevel, fmt, args); \
- va_end(args); \
-} \
-EXPORT_SYMBOL(func)
-
-define_pr_level(__pr_emerg, LOGLEVEL_EMERG);
-define_pr_level(__pr_alert, LOGLEVEL_ALERT);
-define_pr_level(__pr_crit, LOGLEVEL_CRIT);
-define_pr_level(__pr_err, LOGLEVEL_ERR);
-define_pr_level(__pr_warn, LOGLEVEL_WARNING);
-define_pr_level(__pr_notice, LOGLEVEL_NOTICE);
-define_pr_level(__pr_info, LOGLEVEL_INFO);
-#endif
-
-int vprintk_default(int level, const char *fmt, va_list args)
+int vprintk_default(const char *fmt, va_list args)
{
int r;
return r;
}
#endif
- r = vprintk_emit(0, level, NULL, 0, fmt, args);
+ r = vprintk_emit(0, LOGLEVEL_DEFAULT, NULL, 0, fmt, args);
return r;
}
int r;
va_start(args, fmt);
- r = vprintk_func(LOGLEVEL_DEFAULT, fmt, args);
+ r = vprintk_func(fmt, args);
va_end(args);
return r;
projects / cascardo / linux.git / blobdiff