For xonly, move sha512-ppc.pl's table from text to rodata

OpenBSD/macppc will enforce xonly on PowerPC G5, then libcrypto's
sha256 would crash by SIGSEGV, because it can't read text.

Use ELF relocations "@ha" and "@l" to find the table in rodata.  This
might break the PowerPC asm on a not-ELF platform (like AIX or Mac OS)
if someone would try it there.

ok kettenis@ deraadt@

diff --git a/lib/libcrypto/sha/asm/sha512-ppc.pl b/lib/libcrypto/sha/asm/sha512-ppc.pl
index 2a7d5a0..b564929 100755 (executable)
--- a/lib/libcrypto/sha/asm/sha512-ppc.pl
+++ b/lib/libcrypto/sha/asm/sha512-ppc.pl
@@ -220,8 +220,11 @@ $func:
        $LD     $G,`6*$SZ`($ctx)
        $LD     $H,`7*$SZ`($ctx)
 
-       bl      LPICmeup
-LPICedup:
+       bcl     20,31,Lpc
+Lpc:
+       mflr    $Tbl
+       addis   $Tbl,$Tbl,Ltable-Lpc\@ha
+       addi    $Tbl,$Tbl,Ltable-Lpc\@l
        andi.   r0,$inp,3
        bne     Lunaligned
 Laligned:
@@ -377,22 +380,8 @@ $code.=<<___;
        blr
        .long   0
        .byte   0,12,0x14,0,0,0,0,0
-___
-
-# Ugly hack here, because PPC assembler syntax seem to vary too
-# much from platforms to platform...
-$code.=<<___;
-.align 6
-LPICmeup:
-       mflr    r0
-       bcl     20,31,\$+4
-       mflr    $Tbl    ; vvvvvv "distance" between . and 1st data entry
-       addi    $Tbl,$Tbl,`64-8`
-       mtlr    r0
-       blr
-       .long   0
-       .byte   0,12,0x14,0,0,0,0,0
-       .space  `64-9*4`
+       .rodata
+Ltable:
 ___
 $code.=<<___ if ($SZ==8);
        .long   0x428a2f98,0xd728ae22,0x71374491,0x23ef65cd