PATCH: Update libmudflap support for FreeBSD

[Loren James Rittle <rittle at latour dot labs dot mot dot com>]

I have investigated why libmudflap has been failing many tests on
(i386-*-)freebsd7.2 and generated a patch.  This patch solves all
current threading-related issues and an mmap portability issue in two
testcases.  Tested against gcc-4.4.2@150967 and gcc mainline@150945 on
i386-unknown-freebsd7.2 (but I know the history of threading support
back to ~FreeBSD 3 and this will likely help older versions as well).

If someone can confirm that it is portable to pass -1 to mmap for the
fd when the MAP_ANON(YMOUS) flag is present, then I can simplify the
patch before committing it.  It is clear that 0 works on Linux.
mmap(2) on FreeBSD 7.2 specifically states that "The file descriptor
used for creating MAP_ANON must be -1."

Please advise if I may/should commit the test case portion in their
current form.  I assume that I may commit the first two portions with
my FreeBSD maintainer hat since the change is clearly bound by a
__FreeBSD__ macro check (however, I shall await feedback before I do).

Regards,
Loren

2009-08-20  Loren J. Rittle  <ljrittle@acm.org>

	* mf-runtime.c (__mf_init): Support FreeBSD.
	Prime mutex which calls calloc upon first lock to avoid deadlock.
	* mf-hooks1.c (__mf_0fn_mmap): Support FreeBSD.
	Ignore red zone allocation request for initial thread's stack.
	* testsuite/libmudflap.c/pass51-frag.c (MAP_FAILED): Define,
	if not in system header; use it.  On FreeBSD, must pass fd==-1
	with MAP_ANON flag.
	* testsuite/libmudflap.c/fail40-frag.c: Ditto.

Index: libmudflap/mf-runtime.c
===================================================================
--- libmudflap/mf-runtime.c	(revision 150973)
+++ libmudflap/mf-runtime.c	(working copy)
@@ -695,6 +695,12 @@
   if (LIKELY (__mf_starting_p == 0))
     return;
 
+#if defined(__FreeBSD__) && defined(LIBMUDFLAPTH)
+  pthread_self();
+  LOCKTH ();
+  UNLOCKTH ();
+#endif /* Prime mutex which calls calloc upon first lock to avoid deadlock. */
+
   /* This initial bootstrap phase requires that __mf_starting_p = 1. */
 #ifdef PIC
   __mf_resolve_dynamics ();
Index: libmudflap/mf-hooks1.c
===================================================================
--- libmudflap/mf-hooks1.c	(revision 150973)
+++ libmudflap/mf-hooks1.c	(working copy)
@@ -321,6 +321,11 @@
 void *
 __mf_0fn_mmap (void *start, size_t l, int prot, int f, int fd, off_t off)
 {
+#if defined(__FreeBSD__)
+  if (f == 0x1000 && fd == -1 && prot == 0 && off == 0)
+    return 0;
+#endif /* Ignore red zone allocation request for initial thread's stack. */
+
   return (void *) -1;
 }
 #endif
Index: libmudflap/testsuite/libmudflap.c/pass51-frag.c
===================================================================
--- libmudflap/testsuite/libmudflap.c/pass51-frag.c	(revision 150973)
+++ libmudflap/testsuite/libmudflap.c/pass51-frag.c	(working copy)
@@ -13,14 +13,22 @@
 #ifndef MAP_ANONYMOUS
 #define MAP_ANONYMOUS MAP_ANON
 #endif
+#ifndef MAP_FAILED
+#define MAP_FAILED NULL
+#endif
 #ifdef HAVE_MMAP
   void *p;
   unsigned pg = getpagesize ();
   int rc;
 
+#ifdef __FreeBSD__
   p = mmap (NULL, 4 * pg, PROT_READ|PROT_WRITE, 
+            MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+#else
+  p = mmap (NULL, 4 * pg, PROT_READ|PROT_WRITE, 
             MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
-  if (p == NULL)
+#endif
+  if (p == MAP_FAILED)
     return 1;
 
   memset (p, 0, 4*pg);
Index: libmudflap/testsuite/libmudflap.c/fail40-frag.c
===================================================================
--- libmudflap/testsuite/libmudflap.c/fail40-frag.c	(revision 150973)
+++ libmudflap/testsuite/libmudflap.c/fail40-frag.c	(working copy)
@@ -14,6 +14,9 @@
 #ifndef MAP_ANONYMOUS
 #define MAP_ANONYMOUS MAP_ANON
 #endif
+#ifndef MAP_FAILED
+#define MAP_FAILED NULL
+#endif
 #ifdef HAVE_MMAP
   volatile unsigned char *p;
   unsigned num = getpagesize ();
@@ -23,8 +26,12 @@
   /* Get a bit of usable address space.  We really want an 2**N+1-sized object,
      so the low/high addresses wrap when hashed into the lookup cache.  So we
      will manually unregister the entire mmap, then re-register a slice.  */
+#ifdef __FreeBSD__
+  p = mmap (NULL, num, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+#else
   p = mmap (NULL, num, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
-  if (p == NULL)
+#endif
+  if (p == MAP_FAILED)
     return 1;
   /* Now unregister it, as if munmap was called.  But don't actually munmap, so
      we can write into the memory.  */