From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52089C4338F for ; Tue, 24 Aug 2021 07:56:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36DEE60F4A for ; Tue, 24 Aug 2021 07:56:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235062AbhHXH5O (ORCPT ); Tue, 24 Aug 2021 03:57:14 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:37469 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232038AbhHXH5M (ORCPT ); Tue, 24 Aug 2021 03:57:12 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4Gv1dl5t9Fz9sVf; Tue, 24 Aug 2021 09:56:27 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id knBcwI99jOVu; Tue, 24 Aug 2021 09:56:27 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4Gv1dl4lmlz9sTx; Tue, 24 Aug 2021 09:56:27 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 8060A8B7DC; Tue, 24 Aug 2021 09:56:27 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id eI6F6-gc5WXP; Tue, 24 Aug 2021 09:56:27 +0200 (CEST) Received: from po18078vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 170948B7D1; Tue, 24 Aug 2021 09:56:27 +0200 (CEST) Received: by po18078vm.idsi0.si.c-s.fr (Postfix, from userid 0) id C156B6BC7E; Tue, 24 Aug 2021 07:56:26 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [PATCH v3] powerpc/booke: Avoid link stack corruption in several places To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Tue, 24 Aug 2021 07:56:26 +0000 (UTC) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use bcl 20,31,+4 instead of bl in order to preserve link stack. See commit c974809a26a1 ("powerpc/vdso: Avoid link stack corruption in __get_datapage()") for details. Signed-off-by: Christophe Leroy --- v3: Use $+4 as destination instead of label v2: Added missing ; in LOAD_REG_ADDR_PIC() --- arch/powerpc/include/asm/ppc_asm.h | 2 +- arch/powerpc/kernel/exceptions-64e.S | 6 +++--- arch/powerpc/kernel/fsl_booke_entry_mapping.S | 8 ++++---- arch/powerpc/kernel/head_44x.S | 6 +++--- arch/powerpc/kernel/head_fsl_booke.S | 6 +++--- arch/powerpc/mm/nohash/tlb_low.S | 4 ++-- 6 files changed, 16 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index 349fc0ec0dbb..7be24048b8d1 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -260,7 +260,7 @@ GLUE(.,name): /* Be careful, this will clobber the lr register. */ #define LOAD_REG_ADDR_PIC(reg, name) \ - bl 0f; \ + bcl 20,31,$+4; \ 0: mflr reg; \ addis reg,reg,(name - 0b)@ha; \ addi reg,reg,(name - 0b)@l; diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 1401787b0b93..7e0943d9f9b0 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -1127,7 +1127,7 @@ found_iprot: * r3 = MAS0_TLBSEL (for the iprot array) * r4 = SPRN_TLBnCFG */ - bl invstr /* Find our address */ + bcl 20,31,$+4 /* Find our address */ invstr: mflr r6 /* Make it accessible */ mfmsr r7 rlwinm r5,r7,27,31,31 /* extract MSR[IS] */ @@ -1196,7 +1196,7 @@ skpinv: addi r6,r6,1 /* Increment */ mfmsr r6 xori r6,r6,MSR_IS mtspr SPRN_SRR1,r6 - bl 1f /* Find our address */ + bcl 20,31,$+4 /* Find our address */ 1: mflr r6 addi r6,r6,(2f - 1b) mtspr SPRN_SRR0,r6 @@ -1256,7 +1256,7 @@ skpinv: addi r6,r6,1 /* Increment */ * r4 = MAS0 w/TLBSEL & ESEL for the temp mapping */ /* Now we branch the new virtual address mapped by this entry */ - bl 1f /* Find our address */ + bcl 20,31,$+4 /* Find our address */ 1: mflr r6 addi r6,r6,(2f - 1b) tovirt(r6,r6) diff --git a/arch/powerpc/kernel/fsl_booke_entry_mapping.S b/arch/powerpc/kernel/fsl_booke_entry_mapping.S index 8bccce6544b5..dedc17fac8f8 100644 --- a/arch/powerpc/kernel/fsl_booke_entry_mapping.S +++ b/arch/powerpc/kernel/fsl_booke_entry_mapping.S @@ -1,7 +1,7 @@ /* SPDX-License-Identifier: GPL-2.0 */ /* 1. Find the index of the entry we're executing in */ - bl invstr /* Find our address */ + bcl 20,31,$+4 /* Find our address */ invstr: mflr r6 /* Make it accessible */ mfmsr r7 rlwinm r4,r7,27,31,31 /* extract MSR[IS] */ @@ -85,7 +85,7 @@ skpinv: addi r6,r6,1 /* Increment */ addi r6,r6,10 slw r6,r8,r6 /* convert to mask */ - bl 1f /* Find our address */ + bcl 20,31,$+4 /* Find our address */ 1: mflr r7 mfspr r8,SPRN_MAS3 @@ -117,7 +117,7 @@ skpinv: addi r6,r6,1 /* Increment */ xori r6,r4,1 slwi r6,r6,5 /* setup new context with other address space */ - bl 1f /* Find our address */ + bcl 20,31,$+4 /* Find our address */ 1: mflr r9 rlwimi r7,r9,0,20,31 addi r7,r7,(2f - 1b) @@ -207,7 +207,7 @@ next_tlb_setup: lis r7,MSR_KERNEL@h ori r7,r7,MSR_KERNEL@l - bl 1f /* Find our address */ + bcl 20,31,$+4 /* Find our address */ 1: mflr r9 rlwimi r6,r9,0,20,31 addi r6,r6,(2f - 1b) diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S index ddc978a2d381..02d2928d1e01 100644 --- a/arch/powerpc/kernel/head_44x.S +++ b/arch/powerpc/kernel/head_44x.S @@ -70,7 +70,7 @@ _ENTRY(_start); * address. * r21 will be loaded with the physical runtime address of _stext */ - bl 0f /* Get our runtime address */ + bcl 20,31,$+4 /* Get our runtime address */ 0: mflr r21 /* Make it accessible */ addis r21,r21,(_stext - 0b)@ha addi r21,r21,(_stext - 0b)@l /* Get our current runtime base */ @@ -853,7 +853,7 @@ _GLOBAL(init_cpu_state) wmmucr: mtspr SPRN_MMUCR,r3 /* Put MMUCR */ sync - bl invstr /* Find our address */ + bcl 20,31,$+4 /* Find our address */ invstr: mflr r5 /* Make it accessible */ tlbsx r23,0,r5 /* Find entry we are in */ li r4,0 /* Start at TLB entry 0 */ @@ -1045,7 +1045,7 @@ head_start_47x: sync /* Find the entry we are running from */ - bl 1f + bcl 20,31,$+4 1: mflr r23 tlbsx r23,0,r23 tlbre r24,r23,0 diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index 0f9642f36b49..dbf3b89e543c 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -79,7 +79,7 @@ _ENTRY(_start); mr r23,r3 mr r25,r4 - bl 0f + bcl 20,31,$+4 0: mflr r8 addis r3,r8,(is_second_reloc - 0b)@ha lwz r19,(is_second_reloc - 0b)@l(r3) @@ -1132,7 +1132,7 @@ _GLOBAL(switch_to_as1) bne 1b /* Get the tlb entry used by the current running code */ - bl 0f + bcl 20,31,$+4 0: mflr r4 tlbsx 0,r4 @@ -1166,7 +1166,7 @@ _GLOBAL(switch_to_as1) _GLOBAL(restore_to_as0) mflr r0 - bl 0f + bcl 20,31,$+4 0: mflr r9 addi r9,r9,1f - 0b diff --git a/arch/powerpc/mm/nohash/tlb_low.S b/arch/powerpc/mm/nohash/tlb_low.S index 4613bf8e9aae..5add4a51e51f 100644 --- a/arch/powerpc/mm/nohash/tlb_low.S +++ b/arch/powerpc/mm/nohash/tlb_low.S @@ -199,7 +199,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_476_DD2) * Touch enough instruction cache lines to ensure cache hits */ 1: mflr r9 - bl 2f + bcl 20,31,$+4 2: mflr r6 li r7,32 PPC_ICBT(0,R6,R7) /* touch next cache line */ @@ -414,7 +414,7 @@ _GLOBAL(loadcam_multi) * Set up temporary TLB entry that is the same as what we're * running from, but in AS=1. */ - bl 1f + bcl 20,31,$+4 1: mflr r6 tlbsx 0,r8 mfspr r6,SPRN_MAS1 -- 2.25.0