[all] improve backtrace and debugging support

client/src/main.c

@@ -2299,6 +2299,7 @@ int main(int argc, char * argv[])
   lg_shutdown();
 
   config_free();
-  return ret;
 
+  cleanupCrashHandler();
+  return ret;
 }

common/include/common/crash.h

@@ -20,3 +20,4 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include <stdbool.h>
 
 bool installCrashHandler(const char * exe);
+void cleanupCrashHandler(void);

common/include/common/debug.h

@@ -21,10 +21,17 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #define __STDC_FORMAT_MACROS
 #endif
 
+#include <stdlib.h>
 #include <stdio.h>
 #include <inttypes.h>
 #include "time.h"
 
+#ifdef ENABLE_BACKTRACE
+void printBacktrace(void);
+#else
+#define printBacktrace
+#endif
+
 #if defined(_WIN32) && !defined(__GNUC__)
   #define DIRECTORY_SEPARATOR '\\'
 #else
@@ -53,13 +60,22 @@ Place, Suite 330, Boston, MA 02111-1307 USA
   sizeof(s) > 20 && (s)[sizeof(s)-21] == DIRECTORY_SEPARATOR ? (s) + sizeof(s) - 20 : \
   sizeof(s) > 21 && (s)[sizeof(s)-22] == DIRECTORY_SEPARATOR ? (s) + sizeof(s) - 21 : (s))
 
-#define DEBUG_PRINT(type, fmt, ...) do {fprintf(stderr, "%12" PRId64 " " type " %20s:%-4u | %-30s | " fmt "\n", microtime(), STRIPPATH(__FILE__), __LINE__, __FUNCTION__, ##__VA_ARGS__);} while (0)
+#define DEBUG_PRINT(type, fmt, ...) do { \
+  fprintf(stderr, "%12" PRId64 " " type " %20s:%-4u | %-30s | " fmt "\n", \
+      microtime(), STRIPPATH(__FILE__), __LINE__, __FUNCTION__, ##__VA_ARGS__);\
+} while (0)
 
-#define DEBUG_BREAK() DEBUG_PRINT("[ ]", "%s", "================================================================================")
+#define DEBUG_BREAK() DEBUG_PRINT("[ ]", "================================================================================")
 #define DEBUG_INFO(fmt, ...) DEBUG_PRINT("[I]", fmt, ##__VA_ARGS__)
 #define DEBUG_WARN(fmt, ...) DEBUG_PRINT("[W]", fmt, ##__VA_ARGS__)
 #define DEBUG_ERROR(fmt, ...) DEBUG_PRINT("[E]", fmt, ##__VA_ARGS__)
 #define DEBUG_FIXME(fmt, ...) DEBUG_PRINT("[F]", fmt, ##__VA_ARGS__)
+#define DEBUG_FATAL(fmt, ...) do { \
+  DEBUG_BREAK(); \
+  DEBUG_PRINT("[!]", fmt, ##__VA_ARGS__); \
+  printBacktrace(); \
+  abort(); \
+} while(0)
 
 #if defined(DEBUG_SPICE) | defined(DEBUG_IVSHMEM)
   #define DEBUG_PROTO(fmt, args...) DEBUG_PRINT("[P]", fmt, ##args)

common/src/platform/linux/crash.c

@@ -50,18 +50,19 @@ struct crash
   asection     * section;
   asymbol     ** syms;
   long           symCount;
+  bool           loaded;
 };
 
 static struct crash crash = {0};
 
-static void load_symbols(void)
+static bool load_symbols(void)
 {
   bfd_init();
   crash.fd = bfd_openr(crash.exe, NULL);
   if (!crash.fd)
   {
     DEBUG_ERROR("failed to open '%s'", crash.exe);
-    return;
+    return false;
   }
 
   crash.fd->flags |= BFD_DECOMPRESS;
@@ -70,20 +71,20 @@ static void load_symbols(void)
   if (!bfd_check_format_matches(crash.fd, bfd_object, &matching))
   {
     DEBUG_ERROR("executable is not a bfd_object");
-    return;
+    return false;
   }
 
   crash.section = bfd_get_section_by_name(crash.fd, ".text");
   if (!crash.section)
   {
     DEBUG_ERROR("failed to find .text section");
-    return;
+    return false;
   }
 
   if ((bfd_get_file_flags(crash.fd) & HAS_SYMS) == 0)
   {
     DEBUG_ERROR("executable '%s' has no symbols", crash.exe);
-    return;
+    return false;
   }
 
   long storage   = bfd_get_symtab_upper_bound(crash.fd);
@@ -92,8 +93,10 @@ static void load_symbols(void)
   if (crash.symCount < 0)
   {
     DEBUG_ERROR("failed to get the symbol count");
-    return;
+    return false;
   }
+
+  return true;
 }
 
 static bool lookup_address(bfd_vma pc, const char ** filename, const char ** function, unsigned int * line, unsigned int * discriminator)
@@ -131,7 +134,7 @@ static bool lookup_address(bfd_vma pc, const char ** filename, const char ** fun
   return true;
 }
 
-static void cleanup(void)
+void cleanupCrashHandler(void)
 {
   if (crash.syms)
     free(crash.syms);
@@ -168,18 +171,12 @@ static int dl_iterate_phdr_callback(struct dl_phdr_info * info, size_t size, voi
   return 0;
 }
 
-static void crit_err_hdlr(int sig_num, siginfo_t * info, void * ucontext)
+void printBacktrace(void)
 {
   void *             array[50];
   char **            messages;
   int                size, i;
 
-  dl_iterate_phdr(dl_iterate_phdr_callback, NULL);
-  load_symbols();
-
-  DEBUG_ERROR("==== FATAL CRASH (%s) ====", BUILD_VERSION);
-  DEBUG_ERROR("signal %d (%s), address is %p", sig_num, strsignal(sig_num), info->si_addr);
-
   size     = backtrace(array, 50);
   messages = backtrace_symbols(array, size);
 
@@ -210,7 +207,14 @@ static void crit_err_hdlr(int sig_num, siginfo_t * info, void * ucontext)
   }
 
   free(messages);
-  cleanup();
+}
+
+static void crit_err_hdlr(int sig_num, siginfo_t * info, void * ucontext)
+{
+  DEBUG_ERROR("==== FATAL CRASH (%s) ====", BUILD_VERSION);
+  DEBUG_ERROR("signal %d (%s), address is %p", sig_num, strsignal(sig_num), info->si_addr);
+  printBacktrace();
+  cleanupCrashHandler();
   exit(EXIT_FAILURE);
 }
 
@@ -219,6 +223,13 @@ bool installCrashHandler(const char * exe)
   struct sigaction sigact = { 0 };
 
   crash.exe = realpath(exe, NULL);
+  if (!load_symbols())
+  {
+    DEBUG_WARN("Unable to load the binary symbols, not installing crash handler");
+    return true;
+  }
+  dl_iterate_phdr(dl_iterate_phdr_callback, NULL);
+
   sigact.sa_sigaction = crit_err_hdlr;
   sigact.sa_flags = SA_RESTART | SA_SIGINFO;
 
@@ -238,4 +249,12 @@ bool installCrashHandler(const char * exe)
   return true;
 }
 
+void cleanupCrashHandler(void)
+{
+}
+
+void printBacktrace(void)
+{
+}
+
 #endif