patches/glibc/ports-2.10.1/340-dl_execstack-PaX-support.patch
author Johannes Stezenbach <js@sig21.net>
Thu Jul 29 19:47:16 2010 +0200 (2010-07-29)
changeset 2045 fdaa6c7f6dea
permissions -rw-r--r--
cc/gcc: add option to compile against static libstdc++, for gcc-4.4 and newer

Idea and know-how taken from CodeSourcery build script.

Normal build:
$ ldd arm-unknown-linux-uclibcgnueabi-gcc
linux-gate.so.1 => (0xb77f3000)
libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0xb76e8000)
libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb75a1000)
libm.so.6 => /lib/i686/cmov/libm.so.6 (0xb757a000)
/lib/ld-linux.so.2 (0xb77f4000)
libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb755c000)

CC_STATIC_LIBSTDCXX=y:
$ ldd arm-unknown-linux-uclibcgnueabi-gcc
linux-gate.so.1 => (0xb7843000)
libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb76e6000)
/lib/ld-linux.so.2 (0xb7844000)

I made CC_STATIC_LIBSTDCXX default=y since I think
it is always desirable.

Signed-off-by: Johannes Stezenbach <js@sig21.net>
yann@1625
     1
	With latest versions of glibc, a lot of apps failed on a PaX enabled
yann@1625
     2
	system with:
yann@1625
     3
		 cannot enable executable stack as shared object requires: Permission denied
yann@1625
     4
	
yann@1625
     5
	This is due to PaX 'exec-protecting' the stack, and ld.so then trying
yann@1625
     6
	to make the stack executable due to some libraries not containing the
yann@1625
     7
	PT_GNU_STACK section.  Bug #32960.  <azarah@gentoo.org> (12 Nov 2003).
yann@1625
     8
yann@1625
     9
	Patch also NPTL. Bug #116086. <kevquinn@gentoo.org> (20 Dec 2005).
yann@1625
    10
yann@1625
    11
diff -durN glibc-2.10.1.orig/nptl/allocatestack.c glibc-2.10.1/nptl/allocatestack.c
yann@1625
    12
--- glibc-2.10.1.orig/nptl/allocatestack.c	2009-01-29 21:34:16.000000000 +0100
yann@1625
    13
+++ glibc-2.10.1/nptl/allocatestack.c	2009-11-13 00:50:33.000000000 +0100
yann@1625
    14
@@ -326,7 +326,8 @@
yann@1625
    15
 # error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
yann@1625
    16
 #endif
yann@1625
    17
   if (mprotect (stack, len, PROT_READ | PROT_WRITE | PROT_EXEC) != 0)
yann@1625
    18
-    return errno;
yann@1625
    19
+    if (errno != EACCES) /* PAX is enabled */
yann@1625
    20
+    	return errno;
yann@1625
    21
 
yann@1625
    22
   return 0;
yann@1625
    23
 }
yann@1625
    24
diff -durN glibc-2.10.1.orig/sysdeps/unix/sysv/linux/dl-execstack.c glibc-2.10.1/sysdeps/unix/sysv/linux/dl-execstack.c
yann@1625
    25
--- glibc-2.10.1.orig/sysdeps/unix/sysv/linux/dl-execstack.c	2006-01-08 09:21:15.000000000 +0100
yann@1625
    26
+++ glibc-2.10.1/sysdeps/unix/sysv/linux/dl-execstack.c	2009-11-13 00:50:33.000000000 +0100
yann@1625
    27
@@ -63,7 +63,10 @@
yann@1625
    28
       else
yann@1625
    29
 # endif
yann@1625
    30
 	{
yann@1625
    31
-	  result = errno;
yann@1625
    32
+	  if (errno == EACCES)  /* PAX is enabled */
yann@1625
    33
+	    result = 0;
yann@1625
    34
+	  else
yann@1625
    35
+	    result = errno;
yann@1625
    36
 	  goto out;
yann@1625
    37
 	}
yann@1625
    38
     }
yann@1625
    39
@@ -89,7 +92,12 @@
yann@1625
    40
 	page -= size;
yann@1625
    41
       else
yann@1625
    42
 	{
yann@1625
    43
-	  if (errno != ENOMEM)	/* Unexpected failure mode.  */
yann@1625
    44
+	  if (errno == EACCES)		/* PAX is enabled */
yann@1625
    45
+	    {
yann@1625
    46
+	      result = 0;
yann@1625
    47
+	      goto out;
yann@1625
    48
+	    }
yann@1625
    49
+	  else if (errno != ENOMEM)	/* Unexpected failure mode.  */
yann@1625
    50
 	    {
yann@1625
    51
 	      result = errno;
yann@1625
    52
 	      goto out;
yann@1625
    53
@@ -115,7 +123,12 @@
yann@1625
    54
 	page += size;
yann@1625
    55
       else
yann@1625
    56
 	{
yann@1625
    57
-	  if (errno != ENOMEM)	/* Unexpected failure mode.  */
yann@1625
    58
+	  if (errno == EACCES)		/* PAX is enabled */
yann@1625
    59
+	    {
yann@1625
    60
+	      result = 0;
yann@1625
    61
+	      goto out;
yann@1625
    62
+	    }
yann@1625
    63
+	  else if (errno != ENOMEM)	/* Unexpected failure mode.  */
yann@1625
    64
 	    {
yann@1625
    65
 	      result = errno;
yann@1625
    66
 	      goto out;