From: gkoehler <gkoehler@openbsd.org>
Date: Wed, 1 Feb 2023 19:02:50 +0000 (+0000)
Subject: For xonly, move sha512-ppc.pl's table from text to rodata
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=7066554af3d4c0fe04a6394c31866a186f356f84;p=openbsd

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 2a7d5a0e8bc..b5649299dc8 100755
--- 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