kern/log: force log messages to fit in a single line

2 files changed, 14 insertions, 1 deletions

diff --git a/kern/log.c b/kern/log.c
index adba7d33..96be1528 100644
--- a/kern/log.c
+++ b/kern/log.c
@@ -22,6 +22,7 @@
 #include <stddef.h>
 #include <stdio.h>
 #include <stdint.h>
+#include <string.h>
 
 #include <kern/cbuf.h>
 #include <kern/init.h>
@@ -457,6 +458,7 @@ log_vmsg(unsigned int level, const char *format, va_list ap)
     unsigned long flags;
     int nr_chars;
     size_t size;
+    char *ptr;
 
     log_record_init_produce(&record, level);
     nr_chars = vsnprintf(record.buffer, sizeof(record.buffer), format, ap);
@@ -466,6 +468,13 @@ log_vmsg(unsigned int level, const char *format, va_list ap)
         goto out;
     }
 
+    ptr = strchr(record.buffer, '\n');
+
+    if (ptr != NULL) {
+        *ptr = '\0';
+        nr_chars = ptr - record.buffer;
+    }
+
     assert(nr_chars >= 0);
     size = offsetof(struct log_record, buffer) + nr_chars + 1;
 
diff --git a/kern/log.h b/kern/log.h
index a306ba36..003e99b2 100644
--- a/kern/log.h
+++ b/kern/log.h
@@ -48,7 +48,11 @@ void log_start(void);
 /*
  * Generate a message and send it to the log thread.
  *
- * Except for level, the arguments and return value are similar to printf().
+ * The arguments and return value are similar to printf(), with
+ * these exceptions :
+ *  - a level is associated to each log message
+ *  - processing stops at the first terminating null byte or newline
+ *    character, whichever occurs first
  *
  * This function may safely be called in interrupt context.
  */