From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753975AbdBUQhr (ORCPT ); Tue, 21 Feb 2017 11:37:47 -0500 Received: from prod-mail-xrelay07.akamai.com ([23.79.238.175]:65282 "EHLO prod-mail-xrelay07.akamai.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752362AbdBUQhd (ORCPT ); Tue, 21 Feb 2017 11:37:33 -0500 Subject: Re: next-20170217 boot on POWER8 LPAR : WARNING @kernel/jump_label.c:287 To: Sachin Sant , Steven Rostedt References: <1dffdaac-be8b-0052-52d4-a65fed39f894@akamai.com> <02B52EFB-4608-47F3-A81C-B8B52DB11233@linux.vnet.ibm.com> Cc: linux-next@vger.kernel.org, LKML , linuxppc-dev@ozlabs.org, Michael Ellerman From: Jason Baron Message-ID: <20c53e88-acf5-4c4f-cea9-4dd8745814b5@akamai.com> Date: Tue, 21 Feb 2017 11:37:21 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <02B52EFB-4608-47F3-A81C-B8B52DB11233@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/20/2017 10:05 PM, Sachin Sant wrote: > >> On 20-Feb-2017, at 8:27 PM, Jason Baron > > wrote: >> >> Hi, >> >> On 02/19/2017 09:07 AM, Sachin Sant wrote: >>> While booting next-20170217 on a POWER8 LPAR following >>> warning is displayed. >>> >>> Reverting the following commit helps boot cleanly. >>> commit 3821fd35b5 : jump_label: Reduce the size of struct static_key >>> >>> [ 11.393008] ------------[ cut here ]------------ >>> [ 11.393031] WARNING: CPU: 5 PID: 2890 at kernel/jump_label.c:287 >>> static_key_set_entries.isra.10+0x3c/0x50 >> >> Thanks for the report. So this is saying that the jump_entry table is >> not at least 4-byte aligned. I wonder if this fixes it up? >> > > Yes. With this patch the warning is gone. > Hi, Thanks for testing. We probably need something like the following to make sure we don't hit this on other arches. Steve - I will send 4 separate patches for this to get arch maintainers' acks for this? Thanks, -Jason diff --git a/arch/arm/include/asm/jump_label.h b/arch/arm/include/asm/jump_label.h index 34f7b6980d21..9720c2f1850b 100644 --- a/arch/arm/include/asm/jump_label.h +++ b/arch/arm/include/asm/jump_label.h @@ -13,6 +13,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran asm_volatile_goto("1:\n\t" WASM(nop) "\n\t" ".pushsection __jump_table, \"aw\"\n\t" + ".balign 4 \n\t" ".word 1b, %l[l_yes], %c0\n\t" ".popsection\n\t" : : "i" (&((char *)key)[branch]) : : l_yes); @@ -27,6 +28,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool asm_volatile_goto("1:\n\t" WASM(b) " %l[l_yes]\n\t" ".pushsection __jump_table, \"aw\"\n\t" + ".balign 4 \n\t" ".word 1b, %l[l_yes], %c0\n\t" ".popsection\n\t" : : "i" (&((char *)key)[branch]) : : l_yes); diff --git a/arch/mips/include/asm/jump_label.h b/arch/mips/include/asm/jump_label.h index e77672539e8e..51ce97dda3cc 100644 --- a/arch/mips/include/asm/jump_label.h +++ b/arch/mips/include/asm/jump_label.h @@ -31,6 +31,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran asm_volatile_goto("1:\t" NOP_INSN "\n\t" "nop\n\t" ".pushsection __jump_table, \"aw\"\n\t" + ".balign 4 \n\t" WORD_INSN " 1b, %l[l_yes], %0\n\t" ".popsection\n\t" : : "i" (&((char *)key)[branch]) : : l_yes); @@ -45,6 +46,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool asm_volatile_goto("1:\tj %l[l_yes]\n\t" "nop\n\t" ".pushsection __jump_table, \"aw\"\n\t" + ".balign 4 \n\t" WORD_INSN " 1b, %l[l_yes], %0\n\t" ".popsection\n\t" : : "i" (&((char *)key)[branch]) : : l_yes); diff --git a/arch/powerpc/include/asm/jump_label.h b/arch/powerpc/include/asm/jump_label.h index 9a287e0ac8b1..f870a85bac46 100644 --- a/arch/powerpc/include/asm/jump_label.h +++ b/arch/powerpc/include/asm/jump_label.h @@ -24,6 +24,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran asm_volatile_goto("1:\n\t" "nop # arch_static_branch\n\t" ".pushsection __jump_table, \"aw\"\n\t" + ".balign 4 \n\t" JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t" ".popsection \n\t" : : "i" (&((char *)key)[branch]) : : l_yes); @@ -38,6 +39,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool asm_volatile_goto("1:\n\t" "b %l[l_yes] # arch_static_branch_jump\n\t" ".pushsection __jump_table, \"aw\"\n\t" + ".balign 4 \n\t" JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t" ".popsection \n\t" : : "i" (&((char *)key)[branch]) : : l_yes); @@ -63,6 +65,7 @@ struct jump_entry { #define ARCH_STATIC_BRANCH(LABEL, KEY) \ 1098: nop; \ .pushsection __jump_table, "aw"; \ + .balign 4; \ FTR_ENTRY_LONG 1098b, LABEL, KEY; \ .popsection #endif diff --git a/arch/tile/include/asm/jump_label.h b/arch/tile/include/asm/jump_label.h index cde7573f397b..c9f6125c41ef 100644 --- a/arch/tile/include/asm/jump_label.h +++ b/arch/tile/include/asm/jump_label.h @@ -25,6 +25,7 @@ static __always_inline bool arch_static_branch(struct static_key *key, asm_volatile_goto("1:\n\t" "nop" "\n\t" ".pushsection __jump_table, \"aw\"\n\t" + ".balign 4 \n\t" ".quad 1b, %l[l_yes], %0 + %1 \n\t" ".popsection\n\t" : : "i" (key), "i" (branch) : : l_yes); @@ -39,6 +40,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, asm_volatile_goto("1:\n\t" "j %l[l_yes]" "\n\t" ".pushsection __jump_table, \"aw\"\n\t" + ".balign 4 \n\t" ".quad 1b, %l[l_yes], %0 + %1 \n\t" ".popsection\n\t" : : "i" (key), "i" (branch) : : l_yes);