X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=bin%2Foverride.c;h=2385f2b27321b35b97e058f7d5b7b3cc333662c9;hb=7f9b7d3e31101f97831b2e62ca25dc671de14c6b;hp=5996e43c499b44067a2b67b8d4cdbf1840062dc1;hpb=49a14c1606cf8dd3312d7f1a9c14182bfe196c74;p=vlc

diff --git a/bin/override.c b/bin/override.c
index 5996e43c49..2385f2b273 100644
--- a/bin/override.c
+++ b/bin/override.c
@@ -23,6 +23,7 @@
 #endif
 
 #include <stdbool.h>
+#define MAX_ERRORS 5
 
 void vlc_enable_override (void);
 
@@ -33,6 +34,7 @@ void vlc_enable_override (void);
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <dlfcn.h>
 #include <pthread.h>
 #ifdef HAVE_EXECINFO_H
@@ -55,32 +57,37 @@ void vlc_enable_override (void)
     pthread_atfork (NULL, NULL, vlc_reset_override);
 }
 
-static void vlogbug (const char *level, const char *func, const char *fmt,
-                     va_list ap)
+static void vlogbug (unsigned *pc, const char *level, const char *func,
+                     const char *fmt, va_list ap)
 {
 #ifdef HAVE_BACKTRACE
-    const size_t framec = 4;
+    const size_t framec = 5;
     void *framev[framec];
 
     backtrace (framev, framec);
 #endif
     flockfile (stderr);
-    fprintf (stderr, "%s: call to %s(", level, func);
-    vfprintf (stderr, fmt, ap);
-    fputs (")\n", stderr);
-    fflush (stderr);
+    if (*pc < MAX_ERRORS)
+    {
+        (*pc)++;
+        fprintf (stderr, "%s: call to %s(", level, func);
+        vfprintf (stderr, fmt, ap);
+        fputs (")\n", stderr);
+        fflush (stderr);
 #ifdef HAVE_BACKTRACE
-    backtrace_symbols_fd (framev + 2, framec - 2, fileno (stderr));
+        backtrace_symbols_fd (framev + 2, framec - 2, fileno (stderr));
 #endif
+    }
     funlockfile (stderr);
 }
 
-static void logbug (const char *level, const char *func, const char *fmt, ...)
+static void logbug (unsigned *pc, const char *level, const char *func,
+                    const char *fmt, ...)
 {
     va_list ap;
 
     va_start (ap, fmt);
-    vlogbug (level, func, fmt, ap);
+    vlogbug (pc, level, func, fmt, ap);
     va_end (ap);
 }
 
@@ -96,7 +103,12 @@ static void *getsym (const char *name)
     return sym;
 }
 
-#define LOG(level, ...) logbug(level, __func__, __VA_ARGS__)
+#define LOG(level, ...) \
+    do { \
+        static unsigned counter = 0; \
+        logbug(&counter, level, __func__, __VA_ARGS__); \
+    } while (0)
+
 /* Evil non-standard GNU C macro ;)
  *  typeof keyword,
  *  statement-expression,
@@ -216,7 +228,8 @@ void (*signal (int signum, void (*handler) (int))) (int)
         if (!blocked_signal (signum))
             goto error;
         /* For our blocked signals, the handler won't matter much... */
-        LOG("Warning", "%d, %p", signum, handler);
+        if (handler == SIG_DFL)
+            LOG("Warning", "%d, SIG_DFL", signum, handler);
     }
     return CALL(signal, signum, handler);
 error:
@@ -231,7 +244,8 @@ int sigaction (int signum, const struct sigaction *act, struct sigaction *old)
         if ((act->sa_flags & SA_SIGINFO)
          || (act->sa_handler != SIG_IGN && act->sa_handler != SIG_DFL))
             goto error;
-        LOG("Warning", "%d, %p, %p", signum, act, old);
+        if (act->sa_handler == SIG_DFL)
+            LOG("Warning", "%d, %p, SIG_DFL", signum, act);
     }
     return CALL(sigaction, signum, act, old);
 error:
@@ -258,6 +272,20 @@ char *setlocale (int cat, const char *locale)
 }
 
 
+/* strerror() is not thread-safe in theory (POSIX), nor in practice (glibc).
+ * This caused quite nasty crashes in the history of VLC/Linux. */
+char *strerror (int val)
+{
+    if (override)
+    {
+        static const char msg[] =
+            "Error message unavailable (use strerror_r instead of strerror)!";
+        LOG("Blocked", "%d", val);
+        return (char *)msg;
+    }
+    return CALL(strerror, val);
+}
+
 /*** Xlib ****/
 #ifdef HAVE_X11_XLIB_H
 # include <X11/Xlib.h>