Better trap debug

diff --git a/src/trap.c b/src/trap.c
index 8be0c9b18d36282c149f07584b3bc69213859c93..f698ed222a94622dec6ba0946d3fe3010d59bc8b 100644 (file)
--- a/src/trap.c
+++ b/src/trap.c
@@ -34,27 +34,27 @@ char tvh_binshasum[20];
 #include <stdio.h>
 #include <stdarg.h>
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
 #include "tvhead.h"
 #include "sha1.h"
 
-static char traceline[4096];
-static int tracepos = 0;
-
 #define MAXFRAMES 100
 
+static char line1[200];
+static char tmpbuf[1024];
+static char libs[1024];
+
 static void
-traceappend(const char *fmt, ...)
+sappend(char *buf, size_t l, const char *fmt, ...)
 {
   va_list ap;
-  int n;
 
   va_start(ap, fmt);
-  n = vsnprintf(traceline + tracepos, sizeof(traceline) - tracepos, fmt, ap);
+  vsnprintf(buf + strlen(buf), l - strlen(buf), fmt, ap);
   va_end(ap);
-
-  if(n < 1)
-    return;
-  tracepos += n;
 }
 
 
@@ -65,56 +65,77 @@ traphandler(int sig, siginfo_t *si, void *UC)
   ucontext_t *uc = UC;
   static void *frames[MAXFRAMES];
   int nframes = backtrace(frames, MAXFRAMES);
-
+  Dl_info dli;
   int i;
+  const char *reason = NULL;
+
+  tvhlog_spawn(LOG_ALERT, "CRASH", "Signal: %d in %s ", sig, line1);
+
+  switch(sig) {
+  case SIGSEGV:
+    switch(si->si_code) {
+    case SEGV_MAPERR:  reason = "Address not mapped"; break;
+    case SEGV_ACCERR:  reason = "Access error"; break;
+    }
+    break;
+
+  case SIGFPE:
+    switch(si->si_code) {
+    case FPE_INTDIV:  reason = "Integer division by zero"; break;
+    }
+    break;
+  }
+
+  tvhlog_spawn(LOG_ALERT, "CRASH", "Fault address %p (%s)",
+              si->si_addr, reason ?: "N/A");
+
+  tvhlog_spawn(LOG_ALERT, "CRASH", "Loaded libraries: %s ", libs);
+  snprintf(tmpbuf, sizeof(tmpbuf), "Register dump [%d]: ", NGREG);
 
-  traceappend("SIGNAL: %d ", sig); 
-  traceappend("REGDUMP[%d]: ", NGREG);
   for(i = 0; i < NGREG; i++) {
 #if __WORDSIZE == 64
-    traceappend("%016llx ", uc->uc_mcontext.gregs[i]);
+    sappend(tmpbuf, sizeof(tmpbuf), "%016llx ", uc->uc_mcontext.gregs[i]);
 #else
-    traceappend("%08x ", uc->uc_mcontext.gregs[i]);
+    sappend(tmpbuf, sizeof(tmpbuf), "%08x ", uc->uc_mcontext.gregs[i]);
 #endif
   }
+  tvhlog_spawn(LOG_ALERT, "CRASH", "%s", tmpbuf);
 
-  traceappend("STACKTRACE[%d]: ", nframes);
-  for(i = 0; i < nframes; i++)
-    traceappend("%p ", frames[i]);
+  tvhlog_spawn(LOG_ALERT, "CRASH", "STACKTRACE");
 
-  tvhlog_spawn(LOG_ALERT, "CRASH", "%s", traceline);
+  for(i = 0; i < nframes; i++) {
+
+    
+    if(dladdr(frames[i], &dli)) {
+
+      if(dli.dli_sname != NULL && dli.dli_saddr != NULL) {
+       tvhlog_spawn(LOG_ALERT, "CRASH", "%s+0x%tx  (%s)",
+                    dli.dli_sname,
+                    frames[i] - dli.dli_saddr,
+                    dli.dli_fname);
+       continue;
+      }
+
+      if(dli.dli_fname != NULL && dli.dli_fbase != NULL) {
+       tvhlog_spawn(LOG_ALERT, "CRASH", "%s %p",
+                    dli.dli_fname,
+                    frames[i]);
+       continue;
+      }
+
+
+      tvhlog_spawn(LOG_ALERT, "CRASH", "%p", frames[i]);
+    }
+  }
 }
 
-static struct SHA1Context binsum;
 
 
 static int
 callback(struct dl_phdr_info *info, size_t size, void *data)
 {
-  int j;
-
-  // Other lib, just record its presence
-  if(info->dlpi_name[0]) {
-    traceappend("%s ", info->dlpi_name);
-    return 0;
-  }
-
-  // Our self, hash huge R-X segments which in practice is the main text seg.
-
-  for(j = 0; j < info->dlpi_phnum; j++) {
-    if(info->dlpi_phdr[j].p_flags & PF_W)
-      continue;
-
-    if(!(info->dlpi_phdr[j].p_flags & PF_X))
-      continue;
-
-    if(info->dlpi_phdr[j].p_memsz < 65536)
-      continue;
-    
-    SHA1Input(&binsum, 
-             (void *)(info->dlpi_addr + info->dlpi_phdr[j].p_vaddr),
-             info->dlpi_phdr[j].p_memsz);
-  }
+  if(info->dlpi_name[0])
+    sappend(libs, sizeof(libs), "%s ", info->dlpi_name);
   return 0;
 }
 
@@ -129,53 +150,76 @@ trap_init(const char *ver)
   struct sigaction sa, old;
   char path[256];
 
-  traceappend("PRG: %s [%s] CWD: %s ", ver, htsversion_full,
-             getcwd(path, sizeof(path)));
-   
+  struct SHA1Context binsum;
+  int fd;
+
+  
+  if((fd = open("/proc/self/exe", O_RDONLY)) != -1) {
+    struct stat st;
+    if(!fstat(fd, &st)) {
+      char *m = malloc(st.st_size);
+      if(m != NULL) {
+       if(read(fd, m, st.st_size) == st.st_size) {
+         SHA1Reset(&binsum);
+         SHA1Input(&binsum, (void *)m, st.st_size);
+         SHA1Result(&binsum, digest);
+       }
+       free(m);
+      }
+    }
+  }
+  
+  snprintf(line1, sizeof(line1),
+          "PRG: %s (%s) "
+          "[%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x"
+          "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x] "
+          "CWD: %s ", ver, htsversion_full,
+          digest[0],
+          digest[1],
+          digest[2],
+          digest[3],
+          digest[4],
+          digest[5],
+          digest[6],
+          digest[7],
+          digest[8],
+          digest[9],
+          digest[10],
+          digest[11],
+          digest[12],
+          digest[13],
+          digest[14],
+          digest[15],
+          digest[16],
+          digest[17],
+          digest[18],
+          digest[19],
+          getcwd(path, sizeof(path)));
+
+  memcpy(tvh_binshasum, digest, 20);
+
+  dl_iterate_phdr(callback, NULL);
+  
 
   memset(&sa, 0, sizeof(sa));
 
+  sigset_t m;
+  sigemptyset(&m);
+  sigaddset(&m, SIGSEGV);
+  sigaddset(&m, SIGBUS);
+  sigaddset(&m, SIGILL);
+  sigaddset(&m, SIGABRT);
+  sigaddset(&m, SIGFPE);
+
   sa.sa_sigaction = traphandler;
   sa.sa_flags = SA_SIGINFO | SA_RESETHAND;
-
   sigaction(SIGSEGV, &sa, &old);
   sigaction(SIGBUS,  &sa, &old);
   sigaction(SIGILL,  &sa, &old);
   sigaction(SIGABRT, &sa, &old);
   sigaction(SIGFPE,  &sa, &old);
- 
 
-  traceappend("OBJS: ");
-
-  SHA1Reset(&binsum);
-  dl_iterate_phdr(callback, NULL);
-
-  SHA1Result(&binsum, digest);
-
-  traceappend("SHA1: %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x"
-             "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x ",
-             digest[0],
-             digest[1],
-             digest[2],
-             digest[3],
-             digest[4],
-             digest[5],
-             digest[6],
-             digest[7],
-             digest[8],
-             digest[9],
-             digest[10],
-             digest[11],
-             digest[12],
-             digest[13],
-             digest[14],
-             digest[15],
-             digest[16],
-             digest[17],
-             digest[18],
-             digest[19]);
-
-  memcpy(tvh_binshasum, digest, 20);
+  sigprocmask(SIG_UNBLOCK, &m, NULL);
 }
 
 #else