From: Francisco Blas Izquierdo Riera (klondike) <klondike@gentoo.org>
Subject: [PATCH] Fix assemby textrels on rdrand_asm.S on PIC x86

This patch updates the fixes in the assembly in rdrand_asm.S in
sys-apps/rng-tools-5 so it won't generate textrels on PIC systems.
The main fixes are in the use of leal in SETPTR for such systems, the rest is
the usual PIC support stuff.

This should fix Gentoo bug #469962 and help fix #518210

This patch is released under the GPLv2 or a higher version license as is the
original file as long as the author and the tester are credited.

Gentoo-bug-url: https://bugs.gentoo.org/show_bug.cgi?id=469962
Gentoo-bug-url: https://bugs.gentoo.org/show_bug.cgi?id=518210
Upstream-status: Not sent yet
Signed-off-by: Francisco Blas Izquierdo Riera (klondike) <klondike@gentoo.org>
Reported-by: cilly <cilly@cilly.mine.nu>
Reported-by: Manuel Rüger <mrueg@gentoo.org>

--- rng-tools-5.orig/rdrand_asm.S       2014-03-05 01:05:37.000000000 +0100
+++ rng-tools-5/rdrand_asm.S    2014-10-20 04:50:31.900820709 +0200
@@ -2,6 +2,7 @@
  * Copyright (c) 2011-2014, Intel Corporation
  * Authors: Fenghua Yu <fenghua.yu@intel.com>,
  *          H. Peter Anvin <hpa@linux.intel.com>
+ * PIC code by: Francisco Blas Izquierdo Riera (klondike) <klondike@gentoo.org>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -174,7 +175,20 @@
        jmp     4b
 ENDPROC(x86_rdseed_or_rdrand_bytes)
 
+#if defined(__PIC__)
+#undef __i686 /* gcc builtin define gets in our way */
+#define INIT_PIC() \
+       pushl   %ebx\
+       call    __x86.get_pc_thunk.bx\
+       addl    $_GLOBAL_OFFSET_TABLE_, %ebx
+#define END_PIC() \
+       popl    %ebx\
+#define SETPTR(var,ptr) leal (var)@GOTOFF(%ebx),ptr
+#else
+#define INIT_PIC()
+#define END_PIC()
 #define SETPTR(var,ptr)        movl $(var),ptr
+#endif
 #define PTR0   %eax
 #define PTR1   %edx
 #define PTR2   %ecx
@@ -190,6 +204,7 @@
        movl    8(%ebp), %eax
        movl    12(%ebp), %edx
        push    %esi
+       INIT_PIC()
 #endif
        movl    $512, CTR3      /* Number of rounds */
 
@@ -280,6 +295,7 @@
        movdqa  %xmm7, (7*16)(PTR1)
 
 #ifdef __i386__
+       END_PIC()
        pop     %esi
        pop     %ebp
 #endif
@@ -294,6 +310,7 @@
        push    %ebp
        mov     %esp, %ebp
        movl    8(%ebp), %eax
+       INIT_PIC()
 #endif
 
        SETPTR(aes_round_keys, PTR1)
@@ -323,6 +340,7 @@
        call    1f
 
 #ifdef __i386__
+       END_PIC()
        pop     %ebp
 #endif
        ret
@@ -343,6 +361,16 @@
 
 ENDPROC(x86_aes_expand_key)
 
+#if defined(__i386__) && defined(__PIC__)
+       .section        .text.__x86.get_pc_thunk.bx,"axG",@progbits,__x86.get_pc_thunk.bx,comdat
+       .globl  __x86.get_pc_thunk.bx
+       .hidden __x86.get_pc_thunk.bx
+       .type   __x86.get_pc_thunk.bx, @function
+__x86.get_pc_thunk.bx:
+       movl    (%esp), %ebx
+       ret
+#endif
+
        .bss
        .balign 64
 aes_round_keys: