[COMMITTED PATCH] Consolidate Linux and POSIX libc_fatal code.

[Roland McGrath <roland at hack dot frob dot com>]

2013-03-19  Roland McGrath  <roland@hack.frob.com>

	* sysdeps/posix/libc_fatal.c: Include <sys/mman.h>.
	[!WRITEV_FOR_FATAL] (writev_for_fatal): New function.
	[!WRITEV_FOR_FATAL] (WRITEV_FOR_FATAL): New macro; call that.
	[!BEFORE_ABORT] (before_abort): New function.
	[!BEFORE_ABORT] (BEFORE_ABORT): New macro; call that.
	* sysdeps/unix/sysv/linux/libc_fatal.c: Trim includes.
	(writev_for_fatal): New function.
	(WRITEV_FOR_FATAL): New macro; call that.
	(backtrace_and_maps): New function.
	(BEFORE_ABORT): New macro; call that.
	(struct str_list): Type removed.
	(__libc_message, __libc_fatal): Functions removed.
	Include <sysdeps/posix/libc_fatal.c> instead.

--- a/sysdeps/posix/libc_fatal.c
+++ b/sysdeps/posix/libc_fatal.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 1993-2013 Free Software Foundation, Inc.
+/* Catastrophic failure reports.  Generic POSIX.1 version.
+   Copyright (C) 1993-2013 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -27,6 +28,7 @@
 #include <string.h>
 #include <sysdep.h>
 #include <unistd.h>
+#include <sys/mman.h>
 #include <sys/syslog.h>
 #include <sys/uio.h>
 #include <not-cancel.h>
@@ -35,6 +37,25 @@
 #include FATAL_PREPARE_INCLUDE
 #endif
 
+#ifndef WRITEV_FOR_FATAL
+# define WRITEV_FOR_FATAL	writev_for_fatal
+static bool
+writev_for_fatal (int fd, const struct iovec *iov, size_t niov, size_t total)
+{
+  return TEMP_FAILURE_RETRY (__writev (fd, iov, niov)) == total;
+}
+#endif
+
+#ifndef BEFORE_ABORT
+# define BEFORE_ABORT		before_abort
+static void
+before_abort (int do_abort __attribute__ ((unused)),
+              bool written __attribute__ ((unused)),
+              int fd __attribute__ ((unused)))
+{
+}
+#endif
+
 struct str_list
 {
   const char *str;
@@ -42,7 +63,6 @@ struct str_list
   struct str_list *next;
 };
 
-
 /* Abort with an error message.  */
 void
 __libc_message (int do_abort, const char *fmt, ...)
@@ -121,8 +141,7 @@ __libc_message (int do_abort, const char *fmt, ...)
 	  list = list->next;
 	}
 
-      if (TEMP_FAILURE_RETRY (__writev (fd, iov, nlist)) == total)
-	written = true;
+      written = WRITEV_FOR_FATAL (fd, iov, nlist, total);
 
       if (do_abort)
 	{
@@ -131,7 +150,7 @@ __libc_message (int do_abort, const char *fmt, ...)
 	  struct abort_msg_s *buf = __mmap (NULL, total,
 					    PROT_READ | PROT_WRITE,
 					    MAP_ANON | MAP_PRIVATE, -1, 0);
-	  if (buf != MAP_FAILED)
+	  if (__glibc_likely (buf != MAP_FAILED))
 	    {
 	      buf->size = total;
 	      char *wp = buf->msg;
@@ -158,8 +177,12 @@ __libc_message (int do_abort, const char *fmt, ...)
   va_end (ap_copy);
 
   if (do_abort)
-    /* Kill the application.  */
-    abort ();
+    {
+      BEFORE_ABORT (do_abort, written, fd);
+
+      /* Kill the application.  */
+      abort ();
+    }
 }
 
 
--- a/sysdeps/unix/sysv/linux/libc_fatal.c
+++ b/sysdeps/unix/sysv/linux/libc_fatal.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 1993-2013 Free Software Foundation, Inc.
+/* Catastrophic failure reports.  Linux version.
+   Copyright (C) 1993-2013 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -15,195 +16,52 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <atomic.h>
 #include <errno.h>
-#include <fcntl.h>
-#include <ldsodefs.h>
-#include <paths.h>
-#include <stdarg.h>
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sysdep.h>
-#include <unistd.h>
-#include <sys/mman.h>
-#include <sys/syslog.h>
 #include <execinfo.h>
-
-/* Abort with an error message.  */
+#include <fcntl.h>
 #include <not-cancel.h>
+#include <sys/mman.h>
+#include <sys/uio.h>
 
-#ifdef FATAL_PREPARE_INCLUDE
-#include FATAL_PREPARE_INCLUDE
-#endif
-
-struct str_list
+static bool
+writev_for_fatal (int fd, const struct iovec *iov, size_t niov, size_t total)
 {
-  const char *str;
-  size_t len;
-  struct str_list *next;
-};
-
+  INTERNAL_SYSCALL_DECL (err);
+  ssize_t cnt;
+  do
+    cnt = INTERNAL_SYSCALL (writev, err, 3, fd, iov, niov);
+  while (INTERNAL_SYSCALL_ERROR_P (cnt, err)
+         && INTERNAL_SYSCALL_ERRNO (cnt, err) == EINTR);
+  return cnt == total;
+}
+#define WRITEV_FOR_FATAL	writev_for_fatal
 
-/* Abort with an error message.  */
-void
-__libc_message (int do_abort, const char *fmt, ...)
+static void
+backtrace_and_maps (int do_abort, bool written, int fd)
 {
-  va_list ap;
-  va_list ap_copy;
-  int fd = -1;
-
-  va_start (ap, fmt);
-  va_copy (ap_copy, ap);
-
-#ifdef FATAL_PREPARE
-  FATAL_PREPARE;
-#endif
-
-  /* Open a descriptor for /dev/tty unless the user explicitly
-     requests errors on standard error.  */
-  const char *on_2 = __libc_secure_getenv ("LIBC_FATAL_STDERR_");
-  if (on_2 == NULL || *on_2 == '\0')
-    fd = open_not_cancel_2 (_PATH_TTY, O_RDWR | O_NOCTTY | O_NDELAY);
-
-  if (fd == -1)
-    fd = STDERR_FILENO;
-
-  struct str_list *list = NULL;
-  int nlist = 0;
-
-  const char *cp = fmt;
-  while (*cp != '\0')
-    {
-      /* Find the next "%s" or the end of the string.  */
-      const char *next = cp;
-      while (next[0] != '%' || next[1] != 's')
-	{
-	  next = __strchrnul (next + 1, '%');
-
-	  if (next[0] == '\0')
-	    break;
-	}
-
-      /* Determine what to print.  */
-      const char *str;
-      size_t len;
-      if (cp[0] == '%' && cp[1] == 's')
-	{
-	  str = va_arg (ap, const char *);
-	  len = strlen (str);
-	  cp += 2;
-	}
-      else
-	{
-	  str = cp;
-	  len = next - cp;
-	  cp = next;
-	}
-
-      struct str_list *newp = alloca (sizeof (struct str_list));
-      newp->str = str;
-      newp->len = len;
-      newp->next = list;
-      list = newp;
-      ++nlist;
-    }
-
-  bool written = false;
-  if (nlist > 0)
-    {
-      struct iovec *iov = alloca (nlist * sizeof (struct iovec));
-      ssize_t total = 0;
-
-      for (int cnt = nlist - 1; cnt >= 0; --cnt)
-	{
-	  iov[cnt].iov_base = (void *) list->str;
-	  iov[cnt].iov_len = list->len;
-	  total += list->len;
-	  list = list->next;
-	}
-
-      INTERNAL_SYSCALL_DECL (err);
-      ssize_t cnt;
-      do
-	cnt = INTERNAL_SYSCALL (writev, err, 3, fd, iov, nlist);
-      while (INTERNAL_SYSCALL_ERROR_P (cnt, err)
-	     && INTERNAL_SYSCALL_ERRNO (cnt, err) == EINTR);
-
-      if (cnt == total)
-	written = true;
-
-      if (do_abort)
-	{
-	  total = ((total + 1 + GLRO(dl_pagesize) - 1)
-		   & ~(GLRO(dl_pagesize) - 1));
-	  struct abort_msg_s *buf = __mmap (NULL, total,
-					    PROT_READ | PROT_WRITE,
-					    MAP_ANON | MAP_PRIVATE, -1, 0);
-	  if (__builtin_expect (buf != MAP_FAILED, 1))
-	    {
-	      buf->size = total;
-	      char *wp = buf->msg;
-	      for (int cnt = 0; cnt < nlist; ++cnt)
-		wp = mempcpy (wp, iov[cnt].iov_base, iov[cnt].iov_len);
-	      *wp = '\0';
-
-	      /* We have to free the old buffer since the application might
-		 catch the SIGABRT signal.  */
-	      struct abort_msg_s *old = atomic_exchange_acq (&__abort_msg,
-							     buf);
-	      if (old != NULL)
-		__munmap (old, old->size);
-	    }
-	}
-    }
-
-  va_end (ap);
-
-  /* If we  had no success writing the message, use syslog.  */
-  if (! written)
-    vsyslog (LOG_ERR, fmt, ap_copy);
-
-  va_end (ap_copy);
-
-  if (do_abort)
+  if (do_abort > 1 && written)
     {
-      if (do_abort > 1 && written)
-	{
-	  void *addrs[64];
+      void *addrs[64];
 #define naddrs (sizeof (addrs) / sizeof (addrs[0]))
-	  int n = __backtrace (addrs, naddrs);
-	  if (n > 2)
-	    {
+      int n = __backtrace (addrs, naddrs);
+      if (n > 2)
+        {
 #define strnsize(str) str, strlen (str)
 #define writestr(str) write_not_cancel (fd, str)
-	      writestr (strnsize ("======= Backtrace: =========\n"));
-	      __backtrace_symbols_fd (addrs + 1, n - 1, fd);
-
-	      writestr (strnsize ("======= Memory map: ========\n"));
-	      int fd2 = open_not_cancel_2 ("/proc/self/maps", O_RDONLY);
-	      char buf[1024];
-	      ssize_t n2;
-	      while ((n2 = read_not_cancel (fd2, buf, sizeof (buf))) > 0)
-		if (write_not_cancel (fd, buf, n2) != n2)
-		  break;
-	      close_not_cancel_no_status (fd2);
-	    }
-	}
-
-      /* Terminate the process.  */
-      abort ();
+          writestr (strnsize ("======= Backtrace: =========\n"));
+          __backtrace_symbols_fd (addrs + 1, n - 1, fd);
+
+          writestr (strnsize ("======= Memory map: ========\n"));
+          int fd2 = open_not_cancel_2 ("/proc/self/maps", O_RDONLY);
+          char buf[1024];
+          ssize_t n2;
+          while ((n2 = read_not_cancel (fd2, buf, sizeof (buf))) > 0)
+            if (write_not_cancel (fd, buf, n2) != n2)
+              break;
+          close_not_cancel_no_status (fd2);
+        }
     }
 }
+#define BEFORE_ABORT		backtrace_and_maps
 
-
-void
-__libc_fatal (message)
-     const char *message;
-{
-  /* The loop is added only to keep gcc happy.  */
-  while (1)
-    __libc_message (1, "%s", message);
-}
-libc_hidden_def (__libc_fatal)
+#include <sysdeps/posix/libc_fatal.c>