Add AT_PLATFORM env variable to ld.so to override auxv AT_PLATFORM.

3 files changed, 59 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 189187b..1e3e0bf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2010-10-26  Peter Bergner  <bergner@vnet.ibm.com>
+
+	* elf/rtld.c (process_envvars): Added conditional EXTRA_LD_ENVVARS_11
+	macro which allows overriding of AT_PLATFORM using an environment
+	variable.
+	* sysdeps/unix/sysv/linux/powerpc/dl-librecon.h: New file adding
+	definition for the EXTRA_LD_ENVVARS_11 macro.
+
 2011-03-15  Alan Modra  <amodra@gmail.com>
 
 	* elf/dl-reloc.c (_dl_try_allocate_static_tls <TLS_DTV_AT_TP>): Handle
diff --git a/elf/rtld.c b/elf/rtld.c
index 174954b..b13a13f 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -2614,6 +2614,11 @@ process_envvars (enum mode *modep)
 	  break;
 
 	case 11:
+#ifdef EXTRA_LD_ENVVARS_11
+	   /* We might have some extra environment variables with length 11
+	      to handle.  */
+	   EXTRA_LD_ENVVARS_11
+#endif
 	  /* Path where the binary is found.  */
 	  if (!INTUSE(__libc_enable_secure)
 	      && memcmp (envline, "ORIGIN_PATH", 11) == 0)
diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-librecon.h b/sysdeps/unix/sysv/linux/powerpc/dl-librecon.h
new file mode 100644
index 0000000..ef3bcc1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/dl-librecon.h
@@ -0,0 +1,46 @@
+/* Optional code to distinguish library flavors.
+   Copyright (C) 2010, 2011 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Peter Bergner <bergner@vnet.ibm.com>
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _DL_LIBRECON_H
+
+#include <string.h>
+#include <sysdeps/unix/sysv/linux/dl-librecon.h>
+
+/* Recognizing extra environment variables.  */
+#define EXTRA_LD_ENVVARS_11 \
+  if (memcmp (envline, "AT_PLATFORM", 11) == 0)				      \
+    {									      \
+      int platformlen = strlen (&envline[12]);				      \
+      GLRO(dl_platformlen) = platformlen;				      \
+      if (platformlen > 0)						      \
+	{								      \
+	  GLRO(dl_platform) = &envline[12];				      \
+	  break;							      \
+	}								      \
+      GLRO(dl_platform) = NULL;						      \
+      break;		 		 		 		      \
+    }
+
+/* Extra unsecure variables.  The names are all stuffed in a single
+   string which means they have to be terminated with a '\0' explicitly.  */
+#define EXTRA_UNSECURE_ENVVARS \
+  "LD_AT_PLATFORM\0"
+
+#endif /* dl-librecon.h */