1 files changed, 78 insertions, 42 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index 50c33411442d..177fa49357a5 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -194,8 +194,10 @@ static int console_may_schedule;
  */
 
 enum log_flags {
-        LOG_DEFAULT = 0,
-        LOG_NOCONS = 1,         /* already flushed, do not print to console */
+        LOG_NOCONS      = 1,    /* already flushed, do not print to console */
+        LOG_NEWLINE     = 2,    /* text ended with a newline */
+        LOG_PREFIX      = 4,    /* text started with a prefix */
+        LOG_CONT        = 8,    /* text is a fragment of a continuation line */
 };
 
 struct log {
@@ -217,6 +219,7 @@ static DEFINE_RAW_SPINLOCK(logbuf_lock);
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
 static u64 syslog_seq;
 static u32 syslog_idx;
+static enum log_flags syslog_prev;
 static size_t syslog_partial;
 
 /* index and sequence number of the first record stored in the buffer */
@@ -839,13 +842,26 @@ static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
         return len;
 }
 
-static size_t msg_print_text(const struct log *msg, bool syslog,
-                             char *buf, size_t size)
+static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+                             bool syslog, char *buf, size_t size)
 {
         const char *text = log_text(msg);
         size_t text_size = msg->text_len;
+        bool prefix = true;
+        bool newline = true;
         size_t len = 0;
 
+        if ((prev & LOG_CONT) && !(msg->flags & LOG_PREFIX))
+                prefix = false;
+
+        if (msg->flags & LOG_CONT) {
+                if ((prev & LOG_CONT) && !(prev & LOG_NEWLINE))
+                        prefix = false;
+
+                if (!(msg->flags & LOG_NEWLINE))
+                        newline = false;
+        }
+
         do {
                 const char *next = memchr(text, '\n', text_size);
                 size_t text_len;
@@ -863,16 +879,22 @@ static size_t msg_print_text(const struct log *msg, bool syslog,
                             text_len + 1>= size - len)
                                 break;
 
-                        len += print_prefix(msg, syslog, buf + len);
+                        if (prefix)
+                                len += print_prefix(msg, syslog, buf + len);
                         memcpy(buf + len, text, text_len);
                         len += text_len;
-                        buf[len++] = '\n';
+                        if (next || newline)
+                                buf[len++] = '\n';
                 } else {
                         /* SYSLOG_ACTION_* buffer size only calculation */
-                        len += print_prefix(msg, syslog, NULL);
-                        len += text_len + 1;
+                        if (prefix)
+                                len += print_prefix(msg, syslog, NULL);
+                        len += text_len;
+                        if (next || newline)
+                                len++;
                 }
 
+                prefix = true;
                 text = next;
         } while (text);
 
@@ -898,6 +920,7 @@ static int syslog_print(char __user *buf, int size)
                         /* messages are gone, move to first one */
                         syslog_seq = log_first_seq;
                         syslog_idx = log_first_idx;
+                        syslog_prev = 0;
                         syslog_partial = 0;
                 }
                 if (syslog_seq == log_next_seq) {
@@ -907,11 +930,12 @@ static int syslog_print(char __user *buf, int size)
 
                 skip = syslog_partial;
                 msg = log_from_idx(syslog_idx);
-                n = msg_print_text(msg, true, text, LOG_LINE_MAX);
+                n = msg_print_text(msg, syslog_prev, true, text, LOG_LINE_MAX);
                 if (n - syslog_partial <= size) {
                         /* message fits into buffer, move forward */
                         syslog_idx = log_next(syslog_idx);
                         syslog_seq++;
+                        syslog_prev = msg->flags;
                         n -= syslog_partial;
                         syslog_partial = 0;
                 } else if (!len){
@@ -954,6 +978,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
                 u64 next_seq;
                 u64 seq;
                 u32 idx;
+                enum log_flags prev;
 
                 if (clear_seq < log_first_seq) {
                         /* messages are gone, move to first available one */
@@ -967,10 +992,11 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
                  */
                 seq = clear_seq;
                 idx = clear_idx;
+                prev = 0;
                 while (seq < log_next_seq) {
                         struct log *msg = log_from_idx(idx);
 
-                        len += msg_print_text(msg, true, NULL, 0);
+                        len += msg_print_text(msg, prev, true, NULL, 0);
                         idx = log_next(idx);
                         seq++;
                 }
@@ -978,10 +1004,11 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
                 /* move first record forward until length fits into the buffer */
                 seq = clear_seq;
                 idx = clear_idx;
+                prev = 0;
                 while (len > size && seq < log_next_seq) {
                         struct log *msg = log_from_idx(idx);
 
-                        len -= msg_print_text(msg, true, NULL, 0);
+                        len -= msg_print_text(msg, prev, true, NULL, 0);
                         idx = log_next(idx);
                         seq++;
                 }
@@ -990,17 +1017,19 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
                 next_seq = log_next_seq;
 
                 len = 0;
+                prev = 0;
                 while (len >= 0 && seq < next_seq) {
                         struct log *msg = log_from_idx(idx);
                         int textlen;
 
-                        textlen = msg_print_text(msg, true, text, LOG_LINE_MAX);
+                        textlen = msg_print_text(msg, prev, true, text, LOG_LINE_MAX);
                         if (textlen < 0) {
                                 len = textlen;
                                 break;
                         }
                         idx = log_next(idx);
                         seq++;
+                        prev = msg->flags;
 
                         raw_spin_unlock_irq(&logbuf_lock);
                         if (copy_to_user(buf + len, text, textlen))
@@ -1013,6 +1042,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
                                 /* messages are gone, move to next one */
                                 seq = log_first_seq;
                                 idx = log_first_idx;
+                                prev = 0;
                         }
                 }
         }
@@ -1117,6 +1147,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
                         /* messages are gone, move to first one */
                         syslog_seq = log_first_seq;
                         syslog_idx = log_first_idx;
+                        syslog_prev = 0;
                         syslog_partial = 0;
                 }
                 if (from_file) {
@@ -1127,18 +1158,18 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
                          */
                         error = log_next_idx - syslog_idx;
                 } else {
-                        u64 seq;
-                        u32 idx;
+                        u64 seq = syslog_seq;
+                        u32 idx = syslog_idx;
+                        enum log_flags prev = syslog_prev;
 
                         error = 0;
-                        seq = syslog_seq;
-                        idx = syslog_idx;
                         while (seq < log_next_seq) {
                                 struct log *msg = log_from_idx(idx);
 
-                                error += msg_print_text(msg, true, NULL, 0);
+                                error += msg_print_text(msg, prev, true, NULL, 0);
                                 idx = log_next(idx);
                                 seq++;
+                                prev = msg->flags;
                         }
                         error -= syslog_partial;
                 }
@@ -1408,10 +1439,9 @@ asmlinkage int vprintk_emit(int facility, int level,
         static char textbuf[LOG_LINE_MAX];
         char *text = textbuf;
         size_t text_len;
+        enum log_flags lflags = 0;
         unsigned long flags;
         int this_cpu;
-        bool newline = false;
-        bool prefix = false;
         int printed_len = 0;
 
         boot_delay_msec();
@@ -1450,7 +1480,7 @@ asmlinkage int vprintk_emit(int facility, int level,
                 recursion_bug = 0;
                 printed_len += strlen(recursion_msg);
                 /* emit KERN_CRIT message */
-                log_store(0, 2, LOG_DEFAULT, 0,
+                log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
                           NULL, 0, recursion_msg, printed_len);
         }
 
@@ -1463,7 +1493,7 @@ asmlinkage int vprintk_emit(int facility, int level,
         /* mark and strip a trailing newline */
         if (text_len && text[text_len-1] == '\n') {
                 text_len--;
-                newline = true;
+                lflags |= LOG_NEWLINE;
         }
 
         /* strip syslog prefix and extract log level or control flags */
@@ -1473,7 +1503,7 @@ asmlinkage int vprintk_emit(int facility, int level,
                         if (level == -1)
                                 level = text[1] - '0';
                 case 'd':       /* KERN_DEFAULT */
-                        prefix = true;
+                        lflags |= LOG_PREFIX;
                 case 'c':       /* KERN_CONT */
                         text += 3;
                         text_len -= 3;
@@ -1483,22 +1513,20 @@ asmlinkage int vprintk_emit(int facility, int level,
         if (level == -1)
                 level = default_message_loglevel;
 
-        if (dict) {
-                prefix = true;
-                newline = true;
-        }
+        if (dict)
+                lflags |= LOG_PREFIX|LOG_NEWLINE;
 
-        if (!newline) {
+        if (!(lflags & LOG_NEWLINE)) {
                 /*
                  * Flush the conflicting buffer. An earlier newline was missing,
                  * or another task also prints continuation lines.
                  */
-                if (cont.len && (prefix || cont.owner != current))
+                if (cont.len && (lflags & LOG_PREFIX || cont.owner != current))
                         cont_flush();
 
                 /* buffer line if possible, otherwise store it right away */
                 if (!cont_add(facility, level, text, text_len))
-                        log_store(facility, level, LOG_DEFAULT, 0,
+                        log_store(facility, level, lflags | LOG_CONT, 0,
                                   dict, dictlen, text, text_len);
         } else {
                 bool stored = false;
@@ -1510,13 +1538,13 @@ asmlinkage int vprintk_emit(int facility, int level,
                  * flush it out and store this line separately.
                  */
                 if (cont.len && cont.owner == current) {
-                        if (!prefix)
+                        if (!(lflags & LOG_PREFIX))
                                 stored = cont_add(facility, level, text, text_len);
                         cont_flush();
                 }
 
                 if (!stored)
-                        log_store(facility, level, LOG_DEFAULT, 0,
+                        log_store(facility, level, lflags, 0,
                                   dict, dictlen, text, text_len);
         }
         printed_len += text_len;
@@ -1615,8 +1643,8 @@ static struct cont {
 static struct log *log_from_idx(u32 idx) { return NULL; }
 static u32 log_next(u32 idx) { return 0; }
 static void call_console_drivers(int level, const char *text, size_t len) {}
-static size_t msg_print_text(const struct log *msg, bool syslog,
-                             char *buf, size_t size) { return 0; }
+static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+                             bool syslog, char *buf, size_t size) { return 0; }
 static size_t cont_print_text(char *text, size_t size) { return 0; }
 
 #endif /* CONFIG_PRINTK */
@@ -1892,6 +1920,7 @@ void wake_up_klogd(void)
 /* the next printk record to write to the console */
 static u64 console_seq;
 static u32 console_idx;
+static enum log_flags console_prev;
 
 /**
  * console_unlock - unlock the console system
@@ -1952,6 +1981,7 @@ again:
                         /* messages are gone, move to first one */
                         console_seq = log_first_seq;
                         console_idx = log_first_idx;
+                        console_prev = 0;
                 }
 skip:
                 if (console_seq == log_next_seq)
@@ -1975,10 +2005,11 @@ skip:
                 }
 
                 level = msg->level;
-                len = msg_print_text(msg, false, text, sizeof(text));
-
+                len = msg_print_text(msg, console_prev, false,
+                                     text, sizeof(text));
                 console_idx = log_next(console_idx);
                 console_seq++;
+                console_prev = msg->flags;
                 raw_spin_unlock(&logbuf_lock);
 
                 stop_critical_timings();        /* don't trace print latency */
@@ -2241,6 +2272,7 @@ void register_console(struct console *newcon)
                 raw_spin_lock_irqsave(&logbuf_lock, flags);
                 console_seq = syslog_seq;
                 console_idx = syslog_idx;
+                console_prev = syslog_prev;
                 raw_spin_unlock_irqrestore(&logbuf_lock, flags);
                 /*
                  * We're about to replay the log buffer.  Only do this to the
@@ -2534,8 +2566,7 @@ bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
         }
 
         msg = log_from_idx(dumper->cur_idx);
-        l = msg_print_text(msg, syslog,
-                              line, size);
+        l = msg_print_text(msg, 0, syslog, line, size);
 
         dumper->cur_idx = log_next(dumper->cur_idx);
         dumper->cur_seq++;
@@ -2575,6 +2606,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
         u32 idx;
         u64 next_seq;
         u32 next_idx;
+        enum log_flags prev;
         size_t l = 0;
         bool ret = false;
 
@@ -2597,23 +2629,27 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
         /* calculate length of entire buffer */
         seq = dumper->cur_seq;
         idx = dumper->cur_idx;
+        prev = 0;
         while (seq < dumper->next_seq) {
                 struct log *msg = log_from_idx(idx);
 
-                l += msg_print_text(msg, true, NULL, 0);
+                l += msg_print_text(msg, prev, true, NULL, 0);
                 idx = log_next(idx);
                 seq++;
+                prev = msg->flags;
         }
 
         /* move first record forward until length fits into the buffer */
         seq = dumper->cur_seq;
         idx = dumper->cur_idx;
+        prev = 0;
         while (l > size && seq < dumper->next_seq) {
                 struct log *msg = log_from_idx(idx);
 
-                l -= msg_print_text(msg, true, NULL, 0);
+                l -= msg_print_text(msg, prev, true, NULL, 0);
                 idx = log_next(idx);
                 seq++;
+                prev = msg->flags;
         }
 
         /* last message in next interation */
@@ -2621,14 +2657,14 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
         next_idx = idx;
 
         l = 0;
+        prev = 0;
         while (seq < dumper->next_seq) {
                 struct log *msg = log_from_idx(idx);
 
-                l += msg_print_text(msg, syslog,
-                                    buf + l, size - l);
-
+                l += msg_print_text(msg, prev, syslog, buf + l, size - l);
                 idx = log_next(idx);
                 seq++;
+                prev = msg->flags;
         }
 
         dumper->next_seq = next_seq;