patches/glibc/ports-2.10.1/340-dl_execstack-PaX-support.patch
author "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Sun Sep 12 23:38:18 2010 +0200 (2010-09-12)
changeset 2120 48de021b3a9e
permissions -rw-r--r--
arch/mips: add experimental mips64 samples

Both toolchains were tested to successfully:
- _build_ busybox, giving respectively an n32 and an n64 binary
although it has not been run-tested.
- build linux-2.6.36-rc3 for Loongson, giving an n64 vmlinux
(which is expected, due to the way the kernel is built),
and the kernel properly boots!

Credits are due to Julien MOUTHINO (julm on freenode#uClibc) for
testing that the kernel boots on his hardware! Cheers! ;-)

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
     1 	With latest versions of glibc, a lot of apps failed on a PaX enabled
     2 	system with:
     3 		 cannot enable executable stack as shared object requires: Permission denied
     4 	
     5 	This is due to PaX 'exec-protecting' the stack, and ld.so then trying
     6 	to make the stack executable due to some libraries not containing the
     7 	PT_GNU_STACK section.  Bug #32960.  <azarah@gentoo.org> (12 Nov 2003).
     8 
     9 	Patch also NPTL. Bug #116086. <kevquinn@gentoo.org> (20 Dec 2005).
    10 
    11 diff -durN glibc-2.10.1.orig/nptl/allocatestack.c glibc-2.10.1/nptl/allocatestack.c
    12 --- glibc-2.10.1.orig/nptl/allocatestack.c	2009-01-29 21:34:16.000000000 +0100
    13 +++ glibc-2.10.1/nptl/allocatestack.c	2009-11-13 00:50:33.000000000 +0100
    14 @@ -326,7 +326,8 @@
    15  # error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
    16  #endif
    17    if (mprotect (stack, len, PROT_READ | PROT_WRITE | PROT_EXEC) != 0)
    18 -    return errno;
    19 +    if (errno != EACCES) /* PAX is enabled */
    20 +    	return errno;
    21  
    22    return 0;
    23  }
    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
    25 --- glibc-2.10.1.orig/sysdeps/unix/sysv/linux/dl-execstack.c	2006-01-08 09:21:15.000000000 +0100
    26 +++ glibc-2.10.1/sysdeps/unix/sysv/linux/dl-execstack.c	2009-11-13 00:50:33.000000000 +0100
    27 @@ -63,7 +63,10 @@
    28        else
    29  # endif
    30  	{
    31 -	  result = errno;
    32 +	  if (errno == EACCES)  /* PAX is enabled */
    33 +	    result = 0;
    34 +	  else
    35 +	    result = errno;
    36  	  goto out;
    37  	}
    38      }
    39 @@ -89,7 +92,12 @@
    40  	page -= size;
    41        else
    42  	{
    43 -	  if (errno != ENOMEM)	/* Unexpected failure mode.  */
    44 +	  if (errno == EACCES)		/* PAX is enabled */
    45 +	    {
    46 +	      result = 0;
    47 +	      goto out;
    48 +	    }
    49 +	  else if (errno != ENOMEM)	/* Unexpected failure mode.  */
    50  	    {
    51  	      result = errno;
    52  	      goto out;
    53 @@ -115,7 +123,12 @@
    54  	page += size;
    55        else
    56  	{
    57 -	  if (errno != ENOMEM)	/* Unexpected failure mode.  */
    58 +	  if (errno == EACCES)		/* PAX is enabled */
    59 +	    {
    60 +	      result = 0;
    61 +	      goto out;
    62 +	    }
    63 +	  else if (errno != ENOMEM)	/* Unexpected failure mode.  */
    64  	    {
    65  	      result = errno;
    66  	      goto out;