Add __safe_fatal and use it in __pthread_unwind forwarder fallback.

4 files changed, 82 insertions, 9 deletions

diff --git a/ChangeLog b/ChangeLog
index e359c13..d1f3986 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2014-07-31  Roland McGrath  <roland@hack.frob.com>
 
+	* sysdeps/generic/safe-fatal.h: New file.
+	* sysdeps/unix/sysv/linux/safe-fatal.h: New file.
+	* nptl/forward.c: Include it.
+	(__pthread_unwind): Use __safe_fatal as default action, rather
+	than a bogus use of INTERNAL_SYSCALL that could never work.
+
 	* config.h.in (HAVE_BUILTIN_TRAP): New #define to 0.
 	* configure.ac (libc_cv_builtin_trap): New test.
 	* configure: Regenerated.
diff --git a/nptl/forward.c b/nptl/forward.c
index 6355c23..eb3c41f 100644
--- a/nptl/forward.c
+++ b/nptl/forward.c
@@ -23,7 +23,7 @@
 
 #include <shlib-compat.h>
 #include <atomic.h>
-#include <sysdep.h>
+#include <safe-fatal.h>
 
 
 /* Pointers to the libc functions.  */
@@ -202,11 +202,8 @@ FORWARD (pthread_setcancelstate, (int state, int *oldstate), (state, oldstate),
 
 FORWARD (pthread_setcanceltype, (int type, int *oldtype), (type, oldtype), 0)
 
-FORWARD_NORETURN(__pthread_unwind,
-	 void attribute_hidden __attribute ((noreturn)) __cleanup_fct_attribute
-	 attribute_compat_text_section,
-	 (__pthread_unwind_buf_t *buf), (buf), {
-		       /* We cannot call abort() here.  */
-		       INTERNAL_SYSCALL_DECL (err);
-		       INTERNAL_SYSCALL (kill, err, 1, SIGKILL);
-		     })
+FORWARD_NORETURN (__pthread_unwind,
+                  void attribute_hidden __attribute ((noreturn))
+                  __cleanup_fct_attribute attribute_compat_text_section,
+                  (__pthread_unwind_buf_t *buf), (buf),
+                  __safe_fatal ())
diff --git a/sysdeps/generic/safe-fatal.h b/sysdeps/generic/safe-fatal.h
new file mode 100644
index 0000000..6efced3
--- /dev/null
+++ b/sysdeps/generic/safe-fatal.h
@@ -0,0 +1,37 @@
+/* Crash the process immediately, without possibility of deadlock.  Generic.
+   Copyright (C) 2014 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SAFE_FATAL_H
+#define _SAFE_FATAL_H   1
+
+#include <abort-instr.h>
+
+static inline void
+__safe_fatal (void)
+{
+#ifdef ABORT_INSTRUCTION
+  /* This is not guaranteed to be free from the possibility of deadlock,
+     since it might generate a signal that can be caught.  But it's better
+     than nothing.  */
+  ABORT_INSTRUCTION;
+#else
+# error Need an OS-specific or machine-specific safe-fatal.h
+#endif
+}
+
+#endif  /* safe-fatal.h */
diff --git a/sysdeps/unix/sysv/linux/safe-fatal.h b/sysdeps/unix/sysv/linux/safe-fatal.h
new file mode 100644
index 0000000..4de4c04
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/safe-fatal.h
@@ -0,0 +1,33 @@
+/* Crash the process immediately, without possibility of deadlock.  Linux.
+   Copyright (C) 2014 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SAFE_FATAL_H
+#define _SAFE_FATAL_H   1
+
+#include <sysdep.h>
+#include <unistd.h>
+
+static inline void
+__safe_fatal (void)
+{
+  INTERNAL_SYSCALL_DECL (err);
+  pid_t self = INTERNAL_SYSCALL (getpid, err, 0);
+  INTERNAL_SYSCALL (kill, err, 2, self, SIGKILL);
+}
+
+#endif  /* safe-fatal.h */