Revert "printk: guard the amount written per line by devkmsg_read()"

This reverts commit a1c3d4a366a3c5f085a4d049682b170393f7bd9e.

diff --git a/include/linux/printk.h b/include/linux/printk.h
index 58b1fec40d37373001a6d46840702d33e70f1001..9b30871c9149988c87f82a2d7d0de2c50ca89b18 100644 (file)
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -30,8 +30,6 @@ static inline const char *printk_skip_level(const char *buffer)
        return buffer;
 }
 
-#define CONSOLE_EXT_LOG_MAX    8192
-
 /* printk's without a loglevel use this.. */
 #define MESSAGE_LOGLEVEL_DEFAULT CONFIG_MESSAGE_LOGLEVEL_DEFAULT
 

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 9ed8ac369afad60bdac460324e1c7484bc0a1048..3c1aca0c3543829d7dc9574de3c6dbac9d43a0d3 100644 (file)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -506,11 +506,6 @@ ok:
        return security_syslog(type);
 }
 
-static void append_char(char **pp, char *e, char c)
-{
-       if (*pp < e)
-               *(*pp)++ = c;
-}
 
 /* /dev/kmsg - userspace message inject/listen interface */
 struct devkmsg_user {
@@ -518,7 +513,7 @@ struct devkmsg_user {
        u32 idx;
        enum log_flags prev;
        struct mutex lock;
-       char buf[CONSOLE_EXT_LOG_MAX];
+       char buf[8192];
 };
 
 static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from)
@@ -576,7 +571,6 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 {
        struct devkmsg_user *user = file->private_data;
        struct printk_log *msg;
-       char *p, *e;
        u64 ts_usec;
        size_t i;
        char cont = '-';
@@ -586,9 +580,6 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
        if (!user)
                return -EBADF;
 
-       p = user->buf;
-       e = user->buf + sizeof(user->buf);
-
        ret = mutex_lock_interruptible(&user->lock);
        if (ret)
                return ret;
@@ -635,9 +626,9 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
                 ((user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
                cont = '+';
 
-       p += scnprintf(p, e - p, "%u,%llu,%llu,%c;",
-                      (msg->facility << 3) | msg->level,
-                      user->seq, ts_usec, cont);
+       len = sprintf(user->buf, "%u,%llu,%llu,%c;",
+                     (msg->facility << 3) | msg->level,
+                     user->seq, ts_usec, cont);
        user->prev = msg->flags;
 
        /* escape non-printable characters */
@@ -645,11 +636,11 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
                unsigned char c = log_text(msg)[i];
 
                if (c < ' ' || c >= 127 || c == '\\')
-                       p += scnprintf(p, e - p, "\\x%02x", c);
+                       len += sprintf(user->buf + len, "\\x%02x", c);
                else
-                       append_char(&p, e, c);
+                       user->buf[len++] = c;
        }
-       append_char(&p, e, '\n');
+       user->buf[len++] = '\n';
 
        if (msg->dict_len) {
                bool line = true;
@@ -658,31 +649,30 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
                        unsigned char c = log_dict(msg)[i];
 
                        if (line) {
-                               append_char(&p, e, ' ');
+                               user->buf[len++] = ' ';
                                line = false;
                        }
 
                        if (c == '\0') {
-                               append_char(&p, e, '\n');
+                               user->buf[len++] = '\n';
                                line = true;
                                continue;
                        }
 
                        if (c < ' ' || c >= 127 || c == '\\') {
-                               p += scnprintf(p, e - p, "\\x%02x", c);
+                               len += sprintf(user->buf + len, "\\x%02x", c);
                                continue;
                        }
 
-                       append_char(&p, e, c);
+                       user->buf[len++] = c;
                }
-               append_char(&p, e, '\n');
+               user->buf[len++] = '\n';
        }
 
        user->idx = log_next(user->idx);
        user->seq++;
        raw_spin_unlock_irq(&logbuf_lock);
 
-       len = p - user->buf;
        if (len > count) {
                ret = -EINVAL;
                goto out;