X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=bin%2Foverride.c;h=fb4608c969c8d9c16f255a17180a6cade4e9587b;hb=9d30c4c56a7bb37efc1121678b87e9595dd81675;hp=f3eebae5a069ad596a87737bc751750a7b42f9d5;hpb=47e1d944ba1e27a2bf85e5ab083f99418bb22dc9;p=vlc

diff --git a/bin/override.c b/bin/override.c
index f3eebae5a0..fb4608c969 100644
--- a/bin/override.c
+++ b/bin/override.c
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * override.c: overriden function calls for VLC media player
+ * override.c: overridden function calls for VLC media player
  *****************************************************************************
  * Copyright (C) 2010 Rémi Denis-Courmont
  *
@@ -23,6 +23,7 @@
 #endif
 
 #include <stdbool.h>
+#define MAX_ERRORS 5
 
 void vlc_enable_override (void);
 
@@ -33,10 +34,12 @@ 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
 # include <execinfo.h>
+# include <unistd.h>
 #endif
 #ifdef NDEBUG
 # undef HAVE_BACKTRACE
@@ -55,32 +58,37 @@ 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, STDERR_FILENO);
 #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);
 }
 
@@ -96,25 +104,18 @@ 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,
- *  nested function...
+ *  statement-expression
  */
 #define CALL(func, ...) \
-({ \
-    static typeof (func) *sym = NULL; \
-    static pthread_once_t once = PTHREAD_ONCE_INIT; \
-    auto void getsym_once (void); \
-    void getsym_once (void) \
-    { \
-        sym = getsym ( # func); \
-    } \
-    pthread_once (&once, getsym_once); \
-    sym (__VA_ARGS__); \
-})
-
+({ typeof (func) *sym = getsym ( # func); sym (__VA_ARGS__); })
 
 /*** Environment ***
  *
@@ -189,6 +190,7 @@ int rand (void)
 }
 
 
+#if 0
 /** Signals **/
 #include <signal.h>
 
@@ -240,6 +242,7 @@ error:
     LOG("Blocked", "%d, %p, %p", signum, act, old);
     return -1;
 }
+#endif
 
 
 /*** Locales ***
@@ -260,6 +263,20 @@ 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>