- Fix #593: segfault or crash upon rotating logfile.

git-svn-id: file:///svn/unbound/trunk@3156 be551aaa-1e26-0410-a405-d3ace91eadb9

diff --git a/doc/Changelog b/doc/Changelog
index 80efcb1a86defb331c5521d16a94ed17c6fcb253..8ea4dc554f83ca3dd4e2ac4746077c98c6815ca0 100644 (file)
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,3 +1,6 @@
+4 July 2014: Wouter
+       - Fix #593: segfault or crash upon rotating logfile.
+
 3 July 2014: Wouter
        - DLV tests added.
        - signit tool fixup for compile with libldns library.

diff --git a/util/log.c b/util/log.c
index 39d3118a0000fd5830448735eb371296b0c0b837..a3bffbf384f274105a8a1c16704e882b21087127 100644 (file)
--- a/util/log.c
+++ b/util/log.c
@@ -68,6 +68,8 @@ static FILE* logfile = 0;
 static int key_created = 0;
 /** pthread key for thread ids in logfile */
 static ub_thread_key_t logkey;
+/** pthread mutex to protect FILE* */
+static lock_quick_t log_lock;
 /** the identity of this executable/process */
 static const char* ident="unbound";
 #if defined(HAVE_SYSLOG_H) || defined(UB_ON_WINDOWS)
@@ -86,14 +88,19 @@ log_init(const char* filename, int use_syslog, const char* chrootdir)
        if(!key_created) {
                key_created = 1;
                ub_thread_key_create(&logkey, NULL);
+               lock_quick_init(&log_lock);
        }
+       lock_quick_lock(&log_lock);
        if(logfile 
 #if defined(HAVE_SYSLOG_H) || defined(UB_ON_WINDOWS)
        || logging_to_syslog
 #endif
-       )
-       verbose(VERB_QUERY, "switching log to %s", 
-               use_syslog?"syslog":(filename&&filename[0]?filename:"stderr"));
+       ) {
+               lock_quick_unlock(&log_lock); /* verbose() needs the lock */
+               verbose(VERB_QUERY, "switching log to %s", 
+                       use_syslog?"syslog":(filename&&filename[0]?filename:"stderr"));
+               lock_quick_lock(&log_lock);
+       }
        if(logfile && logfile != stderr)
                fclose(logfile);
 #ifdef HAVE_SYSLOG_H
@@ -106,6 +113,7 @@ log_init(const char* filename, int use_syslog, const char* chrootdir)
                 * chroot and no longer be able to access dev/log and so on */
                openlog(ident, LOG_NDELAY, LOG_DAEMON);
                logging_to_syslog = 1;
+               lock_quick_unlock(&log_lock);
                return;
        }
 #elif defined(UB_ON_WINDOWS)
@@ -114,11 +122,13 @@ log_init(const char* filename, int use_syslog, const char* chrootdir)
        }
        if(use_syslog) {
                logging_to_syslog = 1;
+               lock_quick_unlock(&log_lock);
                return;
        }
 #endif /* HAVE_SYSLOG_H */
        if(!filename || !filename[0]) {
                logfile = stderr;
+               lock_quick_unlock(&log_lock);
                return;
        }
        /* open the file for logging */
@@ -127,6 +137,7 @@ log_init(const char* filename, int use_syslog, const char* chrootdir)
                filename += strlen(chrootdir);
        f = fopen(filename, "a");
        if(!f) {
+               lock_quick_unlock(&log_lock);
                log_err("Could not open logfile %s: %s", filename, 
                        strerror(errno));
                return;
@@ -136,11 +147,14 @@ log_init(const char* filename, int use_syslog, const char* chrootdir)
        setvbuf(f, NULL, (int)_IOLBF, 0);
 #endif
        logfile = f;
+       lock_quick_unlock(&log_lock);
 }
 
 void log_file(FILE *f)
 {
+       lock_quick_lock(&log_lock);
        logfile = f;
+       lock_quick_unlock(&log_lock);
 }
 
 void log_thread_set(int* num)
@@ -211,7 +225,11 @@ log_vmsg(int pri, const char* type,
                return;
        }
 #endif /* HAVE_SYSLOG_H */
-       if(!logfile) return;
+       lock_quick_lock(&log_lock);
+       if(!logfile) {
+               lock_quick_unlock(&log_lock);
+               return;
+       }
        if(log_now)
                now = (time_t)*log_now;
        else    now = (time_t)time(NULL);
@@ -236,6 +254,7 @@ log_vmsg(int pri, const char* type,
        /* line buffering does not work on windows */
        fflush(logfile);
 #endif
+       lock_quick_unlock(&log_lock);
 }
 
 /**