GCC: libmudflap.

2 files changed, 74 insertions, 0 deletions

diff --git a/hurd/running/debian/porting/gcc.mdwn b/hurd/running/debian/porting/gcc.mdwn
index ab540908..ec412b9c 100644
--- a/hurd/running/debian/porting/gcc.mdwn
+++ b/hurd/running/debian/porting/gcc.mdwn
@@ -40,3 +40,5 @@ Additionally:
 
   * Also in other places: configure fragments that have `*linux*` cases
     might/should often contain those for us (and GNU/k*BSD) as well.
+
+  * [[`libmudflap`|libmudflap]].
diff --git a/hurd/running/debian/porting/gcc/libmudflap.mdwn b/hurd/running/debian/porting/gcc/libmudflap.mdwn
new file mode 100644
index 00000000..2345828b
--- /dev/null
+++ b/hurd/running/debian/porting/gcc/libmudflap.mdwn
@@ -0,0 +1,72 @@
+[[meta copyright="Copyright © 2008 Free Software Foundation, Inc."]]
+
+[[meta license="""[[toggle id="license" text="GFDL 1.2+"]][[toggleable
+id="license" text="Permission is granted to copy, distribute and/or modify this
+document under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no Invariant
+Sections, no Front-Cover Texts, and no Back-Cover Texts.  A copy of the license
+is included in the section entitled
+[[GNU_Free_Documentation_License|/fdl]]."]]"""]]
+
+Single-threaded use appears to work:
+
+    $ echo 'int main(void) { int *a; a[10]=0; return a[5]; }' | ↩
+      gcc -o a -fmudflap -x c - -lmudflap
+    $ ./a
+    *******
+    mudflap violation 1 (check/write): time=1227208721.922064 ptr=0x1023de0 size=4
+    pc=0x1037a33 location=`<stdin>:1:26 (main)'
+          /usr/lib/libmudflap.so.0(__mf_check+0x33) [0x1037a33]
+          ./a(main+0x7c) [0x80486c4]
+          /usr/lib/libmudflap.so.0(__wrap_main+0x49) [0x1037239]
+    Nearby object 1: checked region begins 68B before and ends 65B before
+    mudflap object 0x80ca268: name=`argv[]'
+    bounds=[0x1023e24,0x1023e2b] size=8 area=static check=0r/0w liveness=0
+    alloc time=1227208721.922064 pc=0x10371d3
+    Nearby object 2: checked region begins 76B before and ends 73B before
+    mudflap object 0x80cb448: name=`environ[]'
+    bounds=[0x1023e2c,0x1023ed7] size=172 area=static check=0r/0w liveness=0
+    alloc time=1227208721.922064 pc=0x10371d3
+    number of nearby objects: 2
+    *******
+    mudflap violation 2 (check/read): time=1227208721.942109 ptr=0x1023dcc size=4
+    pc=0x1037a33 location=`<stdin>:1:35 (main)'
+          /usr/lib/libmudflap.so.0(__mf_check+0x33) [0x1037a33]
+          ./a(main+0xf3) [0x804873b]
+          /usr/lib/libmudflap.so.0(__wrap_main+0x49) [0x1037239]
+    Nearby object 1: checked region begins 88B before and ends 85B before
+    mudflap object 0x80ca268: name=`argv[]'
+    Nearby object 2: checked region begins 96B before and ends 93B before
+    mudflap object 0x80cb448: name=`environ[]'
+    number of nearby objects: 2
+
+Multi-threaded use doesn't:
+
+    $ echo 'int main(void) { int *a; a[10]=0; return a[5]; }' | ↩
+      gcc -include pthread.h -o a -fmudflapth -x c - -lmudflapth -lpthread
+    $ ./a 
+    Killed
+    $ gdb a
+    [...]
+    Starting program: /media/data/home/tschwinge/a 
+    
+    Program received signal EXC_BAD_ACCESS, Could not access memory.
+    0x01180653 in getenv () from /lib/libc.so.0.3
+    (gdb) bt
+    #0  0x01180653 in getenv () from /lib/libc.so.0.3
+    #1  0x01177a02 in __dcigettext () from /lib/libc.so.0.3
+    #2  0x01176a57 in dcgettext () from /lib/libc.so.0.3
+    #3  0x011c03b5 in strerror_r () from /lib/libc.so.0.3
+    #4  0x01175b57 in __assert_perror_fail () from /lib/libc.so.0.3
+    #5  0x0111f1ad in cthread_fork (func=0x114f630 <_hurd_msgport_receive>, arg=0x0)
+        at /build/buildd/hurd-20080607/build-tree/hurd/libpthread/pthread/cthreads-compat.c:41
+    #6  0x0115713e in _hurdsig_init () from /lib/libc.so.0.3
+    #7  0x01140852 in _hurd_proc_init@@GLIBC_2.2.6 () from /lib/libc.so.0.3
+    #8  0x01140e86 in _hurd_init () from /lib/libc.so.0.3
+    #9  0x011690ce in init1 () from /lib/libc.so.0.3
+    #10 0x00001e96 in _dl_start_user () from /lib/ld.so
+    #11 0x00000001 in ?? ()
+    #12 0x01024000 in ?? ()
+    #13 0x00000000 in ?? ()
+
+Also `libmudflap` is pthread-only.