Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754161Ab3JUIwQ (ORCPT ); Mon, 21 Oct 2013 04:52:16 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39700 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754056Ab3JUIwI (ORCPT ); Mon, 21 Oct 2013 04:52:08 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Paul E. McKenney" , "Anton Blanchard" , "Benjamin Herrenschmidt" Date: Mon, 21 Oct 2013 09:46:28 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 098/149] powerpc: Restore registers on error exit from csum_partial_copy_generic() In-Reply-To: X-SA-Exim-Connect-IP: 212.20.242.100 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3624 Lines: 163 3.2.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "Paul E. McKenney" commit 8f21bd0090052e740944f9397e2be5ac7957ded7 upstream. The csum_partial_copy_generic() function saves the PowerPC non-volatile r14, r15, and r16 registers for the main checksum-and-copy loop. Unfortunately, it fails to restore them upon error exit from this loop, which results in silent corruption of these registers in the presumably rare event of an access exception within that loop. This commit therefore restores these register on error exit from the loop. Signed-off-by: Paul E. McKenney Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt [bwh: Backported to 3.2: register name macros use lower-case 'r'] Signed-off-by: Ben Hutchings --- arch/powerpc/lib/checksum_64.S | 54 +++++++++++++++++++++++++++++++----------- 1 file changed, 40 insertions(+), 14 deletions(-) --- a/arch/powerpc/lib/checksum_64.S +++ b/arch/powerpc/lib/checksum_64.S @@ -229,19 +229,35 @@ _GLOBAL(csum_partial) blr - .macro source + .macro srcnr 100: .section __ex_table,"a" .align 3 - .llong 100b,.Lsrc_error + .llong 100b,.Lsrc_error_nr .previous .endm - .macro dest + .macro source +150: + .section __ex_table,"a" + .align 3 + .llong 150b,.Lsrc_error + .previous + .endm + + .macro dstnr 200: .section __ex_table,"a" .align 3 - .llong 200b,.Ldest_error + .llong 200b,.Ldest_error_nr + .previous + .endm + + .macro dest +250: + .section __ex_table,"a" + .align 3 + .llong 250b,.Ldest_error .previous .endm @@ -277,11 +293,11 @@ _GLOBAL(csum_partial_copy_generic) mtctr r6 1: -source; lhz r6,0(r3) /* align to doubleword */ +srcnr; lhz r6,0(r3) /* align to doubleword */ subi r5,r5,2 addi r3,r3,2 adde r0,r0,r6 -dest; sth r6,0(r4) +dstnr; sth r6,0(r4) addi r4,r4,2 bdnz 1b @@ -395,10 +411,10 @@ dest; std r16,56(r4) mtctr r6 3: -source; ld r6,0(r3) +srcnr; ld r6,0(r3) addi r3,r3,8 adde r0,r0,r6 -dest; std r6,0(r4) +dstnr; std r6,0(r4) addi r4,r4,8 bdnz 3b @@ -408,10 +424,10 @@ dest; std r6,0(r4) srdi. r6,r5,2 beq .Lcopy_tail_halfword -source; lwz r6,0(r3) +srcnr; lwz r6,0(r3) addi r3,r3,4 adde r0,r0,r6 -dest; stw r6,0(r4) +dstnr; stw r6,0(r4) addi r4,r4,4 subi r5,r5,4 @@ -419,10 +435,10 @@ dest; stw r6,0(r4) srdi. r6,r5,1 beq .Lcopy_tail_byte -source; lhz r6,0(r3) +srcnr; lhz r6,0(r3) addi r3,r3,2 adde r0,r0,r6 -dest; sth r6,0(r4) +dstnr; sth r6,0(r4) addi r4,r4,2 subi r5,r5,2 @@ -430,10 +446,10 @@ dest; sth r6,0(r4) andi. r6,r5,1 beq .Lcopy_finish -source; lbz r6,0(r3) +srcnr; lbz r6,0(r3) sldi r9,r6,8 /* Pad the byte out to 16 bits */ adde r0,r0,r9 -dest; stb r6,0(r4) +dstnr; stb r6,0(r4) .Lcopy_finish: addze r0,r0 /* add in final carry */ @@ -443,6 +459,11 @@ dest; stb r6,0(r4) blr .Lsrc_error: + ld r14,STK_REG(r14)(r1) + ld r15,STK_REG(r15)(r1) + ld r16,STK_REG(r16)(r1) + addi r1,r1,STACKFRAMESIZE +.Lsrc_error_nr: cmpdi 0,r7,0 beqlr li r6,-EFAULT @@ -450,6 +471,11 @@ dest; stb r6,0(r4) blr .Ldest_error: + ld r14,STK_REG(r14)(r1) + ld r15,STK_REG(r15)(r1) + ld r16,STK_REG(r16)(r1) + addi r1,r1,STACKFRAMESIZE +.Ldest_error_nr: cmpdi 0,r8,0 beqlr li r6,-EFAULT -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/