cygwin: Fix crashes under AllocationPreference=0x100000 condition

        * cygtls.h: Include cygtls_padsize.h and define CYGTLS_PADSIZE there.
        * cygtls_padsize.h: New file.  Define CYGTLS_PADSIZE.
        * environ.cc (parse_options): Fix NULL pointer access.
        * init.cc (threadfunc_fe): Do not force stack align on x86_64.

        * strace.cc (main2): Rename from main.
        (main): Make room for _cygtls area on stack and just call main2.  Add
        comment to explain why.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

8 files changed, 55 insertions, 13 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index a8f654348..1fb4c79cd 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,10 @@
+2015-07-29  Corinna Vinschen  <corinna@vinschen.de>
+
+	* cygtls.h: Include cygtls_padsize.h and define CYGTLS_PADSIZE there.
+	* cygtls_padsize.h: New file.  Define CYGTLS_PADSIZE.
+	* environ.cc (parse_options): Fix NULL pointer access.
+	* init.cc (threadfunc_fe): Do not force stack align on x86_64.
+
 2015-07-23  Corinna Vinschen  <corinna@vinschen.de>
 
 	* exceptions.cc (__cont_link_context): x86_64: align stack and reserve
diff --git a/winsup/cygwin/cygtls.h b/winsup/cygwin/cygtls.h
index 91ed4d42f..c8615af70 100644
--- a/winsup/cygwin/cygtls.h
+++ b/winsup/cygwin/cygtls.h
@@ -271,12 +271,7 @@ private:
 };
 #pragma pack(pop)
 
-/* FIXME: Find some way to autogenerate this value */
-#ifdef __x86_64__
-const int CYGTLS_PADSIZE = 12800;	/* Must be 16-byte aligned */
-#else
-const int CYGTLS_PADSIZE = 12700;
-#endif
+#include "cygtls_padsize.h"
 
 /*gentls_offsets*/
 
diff --git a/winsup/cygwin/cygtls_padsize.h b/winsup/cygwin/cygtls_padsize.h
new file mode 100644
index 000000000..c1782c586
--- /dev/null
+++ b/winsup/cygwin/cygtls_padsize.h
@@ -0,0 +1,14 @@
+/* cygtls_padsize.h: Extra file to be included from utils.
+
+   Copyright 2015 Red Hat, Inc.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+/* FIXME: Find some way to autogenerate this value */
+#ifdef __x86_64__
+const int CYGTLS_PADSIZE = 12800;	/* Must be 16-byte aligned */
+#else
+const int CYGTLS_PADSIZE = 12700;
+#endif
diff --git a/winsup/cygwin/environ.cc b/winsup/cygwin/environ.cc
index d210504a2..8f25fb19e 100644
--- a/winsup/cygwin/environ.cc
+++ b/winsup/cygwin/environ.cc
@@ -232,8 +232,7 @@ parse_options (const char *inbuf)
 	    switch (k->disposition)
 	      {
 	      case isfunc:
-		k->setting.func ((!eq || !istrue) ?
-		  k->values[istrue].s : eq);
+		k->setting.func ((!eq || !istrue) ?  k->values[istrue].s : eq);
 		debug_printf ("%s (called func)", k->name);
 		break;
 	      case setdword:
@@ -258,10 +257,12 @@ parse_options (const char *inbuf)
 		break;
 	      }
 
+	    int n = 0;
 	    if (eq)
-	      *--eq = ch;
-
-	    int n = eq - p;
+	      {
+		*--eq = ch;
+		n = eq - p;
+	      }
 	    p = strdup (keyword_here);
 	    if (n > 0)
 	      p[n] = ':';
diff --git a/winsup/cygwin/init.cc b/winsup/cygwin/init.cc
index 78e88b94b..0e8b1bae3 100644
--- a/winsup/cygwin/init.cc
+++ b/winsup/cygwin/init.cc
@@ -25,8 +25,10 @@ static bool dll_finished_loading;
 static void WINAPI
 threadfunc_fe (VOID *arg)
 {
+#ifndef __x86_64__
   (void)__builtin_return_address(1);
   asm volatile ("andl $-16,%%esp" ::: "%esp");
+#endif
   _cygtls::call ((DWORD (*)  (void *, void *)) TlsGetValue (_my_oldfunc), arg);
 }
 
diff --git a/winsup/cygwin/release/2.2.0 b/winsup/cygwin/release/2.2.0
index c34888f95..5d8cdd0b2 100644
--- a/winsup/cygwin/release/2.2.0
+++ b/winsup/cygwin/release/2.2.0
@@ -21,3 +21,6 @@ Bug Fixes
 
 - Fix potential hang running ldd(1).
   Addresses: https://cygwin.com/ml/cygwin/2015-07/msg00292.html
+
+- Fix crashes under AllocationPreference=0x100000 condition
+  Addresses: https://cygwin.com/ml/cygwin/2015-02/msg00765.html
diff --git a/winsup/utils/ChangeLog b/winsup/utils/ChangeLog
index bc8835fd0..21a7c4915 100644
--- a/winsup/utils/ChangeLog
+++ b/winsup/utils/ChangeLog
@@ -1,3 +1,9 @@
+2015-07-29  Corinna Vinschen  <corinna@vinschen.de>
+
+	* strace.cc (main2): Rename from main.
+	(main): Make room for _cygtls area on stack and just call main2.  Add
+	comment to explain why.
+
 2015-07-20  Corinna Vinschen  <corinna@vinschen.de>
 
 	* ldd.cc (STATUS_DLL_NOT_FOUND): Drop definition.
diff --git a/winsup/utils/strace.cc b/winsup/utils/strace.cc
index 4b0d669e7..4c0c04f1f 100644
--- a/winsup/utils/strace.cc
+++ b/winsup/utils/strace.cc
@@ -1,7 +1,7 @@
 /* strace.cc
 
    Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
-   2009, 2010, 2011, 2012, 2013 Red Hat Inc.
+   2009, 2010, 2011, 2012, 2013, 2015 Red Hat Inc.
 
    Written by Chris Faylor <cgf@redhat.com>
 
@@ -26,6 +26,7 @@ details. */
 #include "../cygwin/include/sys/strace.h"
 #include "../cygwin/include/sys/cygwin.h"
 #include "../cygwin/include/cygwin/version.h"
+#include "../cygwin/cygtls_padsize.h"
 #include "path.h"
 #undef cygwin_internal
 #include "loadlib.h"
@@ -1025,7 +1026,7 @@ print_version ()
 }
 
 int
-main (int argc, char **argv)
+main2 (int argc, char **argv)
 {
   unsigned mask = 0;
   FILE *ofile = NULL;
@@ -1165,6 +1166,19 @@ character #%d.\n", optarg, (int) (endptr - optarg), endptr);
   return 0;
 }
 
+int
+main (int argc, char **argv)
+{
+  /* Make sure to have room for the _cygtls area *and* to initialize it.
+     This is required to make sure cygwin_internal calls into Cygwin work
+     reliably.  This problem has been noticed under AllocationPreference
+     registry setting to 0x100000 (TOP_DOWN). */
+  char buf[CYGTLS_PADSIZE];
+
+  memset (buf, 0, sizeof (buf));
+  exit (main2 (argc, argv));
+}
+
 #undef CloseHandle
 
 static BOOL