From patchwork Wed Jul 15 12:32:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Leoshkevich X-Patchwork-Id: 1329452 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B6GyR74wJz9sTX for ; Wed, 15 Jul 2020 22:33:35 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730936AbgGOMdc (ORCPT ); Wed, 15 Jul 2020 08:33:32 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:21864 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730602AbgGOMdb (ORCPT ); Wed, 15 Jul 2020 08:33:31 -0400 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06FCWF2K060777; Wed, 15 Jul 2020 08:33:20 -0400 Received: from ppma06fra.de.ibm.com (48.49.7a9f.ip4.static.sl-reverse.com [159.122.73.72]) by mx0a-001b2d01.pphosted.com with ESMTP id 32792w4w7b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 15 Jul 2020 08:33:19 -0400 Received: from pps.filterd (ppma06fra.de.ibm.com [127.0.0.1]) by ppma06fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06FCX8s6019160; Wed, 15 Jul 2020 12:33:08 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma06fra.de.ibm.com with ESMTP id 328rbqs1v3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 15 Jul 2020 12:33:08 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06FCVeTW61473144 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 Jul 2020 12:31:40 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1A3244C044; Wed, 15 Jul 2020 12:33:03 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9F9284C040; Wed, 15 Jul 2020 12:33:02 +0000 (GMT) Received: from localhost.localdomain (unknown [9.145.186.215]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 15 Jul 2020 12:33:02 +0000 (GMT) From: Ilya Leoshkevich To: Alexei Starovoitov , Daniel Borkmann Cc: bpf@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Ilya Leoshkevich Subject: [PATCH 1/4] s390/kernel: unify EX_TABLE* implementations Date: Wed, 15 Jul 2020 14:32:24 +0200 Message-Id: <20200715123227.912866-2-iii@linux.ibm.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200715123227.912866-1-iii@linux.ibm.com> References: <20200715123227.912866-1-iii@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-15_10:2020-07-15,2020-07-15 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 mlxlogscore=999 priorityscore=1501 lowpriorityscore=0 clxscore=1015 adultscore=0 impostorscore=0 spamscore=0 malwarescore=0 bulkscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007150102 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Replace three implementations with one using using __stringify_in_c macro conveniently "borrowed" from powerpc and microblaze. Signed-off-by: Ilya Leoshkevich --- arch/s390/include/asm/asm-const.h | 12 +++++++++++ arch/s390/include/asm/linkage.h | 34 ++++++++++--------------------- 2 files changed, 23 insertions(+), 23 deletions(-) create mode 100644 arch/s390/include/asm/asm-const.h diff --git a/arch/s390/include/asm/asm-const.h b/arch/s390/include/asm/asm-const.h new file mode 100644 index 000000000000..11f615eb0066 --- /dev/null +++ b/arch/s390/include/asm/asm-const.h @@ -0,0 +1,12 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_S390_ASM_CONST_H +#define _ASM_S390_ASM_CONST_H + +#ifdef __ASSEMBLY__ +# define stringify_in_c(...) __VA_ARGS__ +#else +/* This version of stringify will deal with commas... */ +# define __stringify_in_c(...) #__VA_ARGS__ +# define stringify_in_c(...) __stringify_in_c(__VA_ARGS__) " " +#endif +#endif /* _ASM_S390_ASM_CONST_H */ diff --git a/arch/s390/include/asm/linkage.h b/arch/s390/include/asm/linkage.h index 7f22262b0e46..1b52c07b5642 100644 --- a/arch/s390/include/asm/linkage.h +++ b/arch/s390/include/asm/linkage.h @@ -2,38 +2,26 @@ #ifndef __ASM_LINKAGE_H #define __ASM_LINKAGE_H +#include #include #define __ALIGN .align 4, 0x07 #define __ALIGN_STR __stringify(__ALIGN) -#ifndef __ASSEMBLY__ - /* * Helper macro for exception table entries */ -#define EX_TABLE(_fault, _target) \ - ".section __ex_table,\"a\"\n" \ - ".align 4\n" \ - ".long (" #_fault ") - .\n" \ - ".long (" #_target ") - .\n" \ - ".previous\n" - -#else /* __ASSEMBLY__ */ -#define EX_TABLE(_fault, _target) \ - .section __ex_table,"a" ; \ - .align 4 ; \ - .long (_fault) - . ; \ - .long (_target) - . ; \ - .previous +#define __EX_TABLE(_section, _fault, _target) \ + stringify_in_c(.section _section,"a";) \ + stringify_in_c(.align 4;) \ + stringify_in_c(.long (_fault) - .;) \ + stringify_in_c(.long (_target) - .;) \ + stringify_in_c(.previous) -#define EX_TABLE_DMA(_fault, _target) \ - .section .dma.ex_table, "a" ; \ - .align 4 ; \ - .long (_fault) - . ; \ - .long (_target) - . ; \ - .previous +#define EX_TABLE(_fault, _target) \ + __EX_TABLE(__ex_table, _fault, _target) +#define EX_TABLE_DMA(_fault, _target) \ + __EX_TABLE(.dma.ex_table, _fault, _target) -#endif /* __ASSEMBLY__ */ #endif From patchwork Wed Jul 15 12:32:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Leoshkevich X-Patchwork-Id: 1329453 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B6Gyj6zp9z9s1x for ; Wed, 15 Jul 2020 22:33:49 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726652AbgGOMdt (ORCPT ); Wed, 15 Jul 2020 08:33:49 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38622 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726335AbgGOMdt (ORCPT ); Wed, 15 Jul 2020 08:33:49 -0400 Received: from pps.filterd (m0127361.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06FCXUhu045625; Wed, 15 Jul 2020 08:33:35 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 327u1jk22j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 15 Jul 2020 08:33:33 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06FCUGJa011361; Wed, 15 Jul 2020 12:33:19 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma04ams.nl.ibm.com with ESMTP id 329nmygmrj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 15 Jul 2020 12:33:19 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06FCXEM012386394 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 Jul 2020 12:33:14 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 566A44C044; Wed, 15 Jul 2020 12:33:14 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C2E774C050; Wed, 15 Jul 2020 12:33:13 +0000 (GMT) Received: from localhost.localdomain (unknown [9.145.186.215]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 15 Jul 2020 12:33:13 +0000 (GMT) From: Ilya Leoshkevich To: Alexei Starovoitov , Daniel Borkmann Cc: bpf@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Ilya Leoshkevich Subject: [PATCH 2/4] s390/kernel: expand the exception table logic to allow new handling options Date: Wed, 15 Jul 2020 14:32:25 +0200 Message-Id: <20200715123227.912866-3-iii@linux.ibm.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200715123227.912866-1-iii@linux.ibm.com> References: <20200715123227.912866-1-iii@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-15_11:2020-07-15,2020-07-15 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 malwarescore=0 spamscore=0 priorityscore=1501 clxscore=1015 mlxlogscore=999 suspectscore=0 phishscore=0 bulkscore=0 impostorscore=0 mlxscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007150105 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This is a s390 port of commit 548acf19234d ("x86/mm: Expand the exception table logic to allow new handling options"), which is needed for implementing BPF_PROBE_MEM on s390. The new handler field is made 64-bit in order to allow pointing from dynamically allocated entries to handlers in kernel text. Unlike on x86, NULL is used instead of ex_handler_default. This is because exception tables are used by boot/text_dma.S, and it would be a pain to preserve ex_handler_default. The new infrastructure is ignored in early_pgm_check_handler, since there is no pt_regs. Signed-off-by: Ilya Leoshkevich Reviewed-by: Heiko Carstens --- arch/s390/include/asm/extable.h | 50 +++++++++++++++++++++++++++++---- arch/s390/include/asm/linkage.h | 3 +- arch/s390/kernel/kprobes.c | 4 +-- arch/s390/kernel/traps.c | 7 ++--- arch/s390/mm/fault.c | 4 +-- scripts/sorttable.c | 25 +++++++++++++++++ 6 files changed, 76 insertions(+), 17 deletions(-) diff --git a/arch/s390/include/asm/extable.h b/arch/s390/include/asm/extable.h index ae27f756b409..8f0c60f2fe3a 100644 --- a/arch/s390/include/asm/extable.h +++ b/arch/s390/include/asm/extable.h @@ -1,12 +1,20 @@ /* SPDX-License-Identifier: GPL-2.0 */ #ifndef __S390_EXTABLE_H #define __S390_EXTABLE_H + +#include +#include + /* - * The exception table consists of pairs of addresses: the first is the - * address of an instruction that is allowed to fault, and the second is - * the address at which the program should continue. No registers are - * modified, so it is entirely up to the continuation code to figure out - * what to do. + * The exception table consists of three addresses: + * + * - Address of an instruction that is allowed to fault. + * - Address at which the program should continue. + * - Optional address of handler that takes pt_regs * argument and runs in + * interrupt context. + * + * No registers are modified, so it is entirely up to the continuation code + * to figure out what to do. * * All the routines below use bits of fixup code that are out of line * with the main instruction path. This means when everything is well, @@ -17,6 +25,7 @@ struct exception_table_entry { int insn, fixup; + long handler; }; extern struct exception_table_entry *__start_dma_ex_table; @@ -29,6 +38,37 @@ static inline unsigned long extable_fixup(const struct exception_table_entry *x) return (unsigned long)&x->fixup + x->fixup; } +typedef bool (*ex_handler_t)(const struct exception_table_entry *, + struct pt_regs *); + +static inline ex_handler_t +ex_fixup_handler(const struct exception_table_entry *x) +{ + return (ex_handler_t)((unsigned long)&x->handler + x->handler); +} + +static inline bool ex_handle(const struct exception_table_entry *x, + struct pt_regs *regs) +{ + ex_handler_t handler = ex_fixup_handler(x); + + if (unlikely(handler)) + return handler(x, regs); + regs->psw.addr = extable_fixup(x); + return true; +} + #define ARCH_HAS_RELATIVE_EXTABLE +static inline void swap_ex_entry_fixup(struct exception_table_entry *a, + struct exception_table_entry *b, + struct exception_table_entry tmp, + int delta) +{ + a->fixup = b->fixup + delta; + b->fixup = tmp.fixup - delta; + a->handler = b->handler + delta; + b->handler = tmp.handler - delta; +} + #endif diff --git a/arch/s390/include/asm/linkage.h b/arch/s390/include/asm/linkage.h index 1b52c07b5642..83ff5a35d522 100644 --- a/arch/s390/include/asm/linkage.h +++ b/arch/s390/include/asm/linkage.h @@ -14,9 +14,10 @@ #define __EX_TABLE(_section, _fault, _target) \ stringify_in_c(.section _section,"a";) \ - stringify_in_c(.align 4;) \ + stringify_in_c(.align 8;) \ stringify_in_c(.long (_fault) - .;) \ stringify_in_c(.long (_target) - .;) \ + stringify_in_c(.quad 0 - .;) \ stringify_in_c(.previous) #define EX_TABLE(_fault, _target) \ diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index 548d0ea9808d..d2a71d872638 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -523,10 +523,8 @@ static int kprobe_trap_handler(struct pt_regs *regs, int trapnr) * zero, try to fix up. */ entry = s390_search_extables(regs->psw.addr); - if (entry) { - regs->psw.addr = extable_fixup(entry); + if (entry && ex_handle(entry, regs)) return 1; - } /* * fixup_exception() could not handle it, diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c index ff9cc4c3290e..8d1e8a1a97df 100644 --- a/arch/s390/kernel/traps.c +++ b/arch/s390/kernel/traps.c @@ -50,11 +50,8 @@ void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str) } else { const struct exception_table_entry *fixup; fixup = s390_search_extables(regs->psw.addr); - if (fixup) - regs->psw.addr = extable_fixup(fixup); - else { + if (!fixup || !ex_handle(fixup, regs)) die(regs, str); - } } } @@ -251,7 +248,7 @@ void monitor_event_exception(struct pt_regs *regs) case BUG_TRAP_TYPE_NONE: fixup = s390_search_extables(regs->psw.addr); if (fixup) - regs->psw.addr = extable_fixup(fixup); + ex_handle(fixup, regs); break; case BUG_TRAP_TYPE_WARN: break; diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index d53c2e2ea1fd..c4c6cafef3f4 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -255,10 +255,8 @@ static noinline void do_no_context(struct pt_regs *regs) /* Are we prepared to handle this kernel fault? */ fixup = s390_search_extables(regs->psw.addr); - if (fixup) { - regs->psw.addr = extable_fixup(fixup); + if (fixup && ex_handle(fixup, regs)) return; - } /* * Oops. The kernel tried to access some bad page. We'll have to diff --git a/scripts/sorttable.c b/scripts/sorttable.c index ec6b5e81eba1..a4b8415ba71c 100644 --- a/scripts/sorttable.c +++ b/scripts/sorttable.c @@ -255,6 +255,29 @@ static void x86_sort_relative_table(char *extab_image, int image_size) } } +static void s390_sort_relative_table(char *extab_image, int image_size) +{ + int i; + + for (i = 0; i < image_size; i += 16) { + char *loc = extab_image + i; + + w(r((uint32_t *)loc) + i, (uint32_t *)loc); + w(r((uint32_t *)(loc + 4)) + (i + 4), (uint32_t *)(loc + 4)); + w8(r8((uint64_t *)(loc + 8)) + (i + 8), (uint64_t *)(loc + 8)); + } + + qsort(extab_image, image_size / 16, 16, compare_relative_table); + + for (i = 0; i < image_size; i += 16) { + char *loc = extab_image + i; + + w(r((uint32_t *)loc) - i, (uint32_t *)loc); + w(r((uint32_t *)(loc + 4)) - (i + 4), (uint32_t *)(loc + 4)); + w8(r8((uint64_t *)(loc + 8)) - (i + 8), (uint64_t *)(loc + 8)); + } +} + static int do_file(char const *const fname, void *addr) { int rc = -1; @@ -297,6 +320,8 @@ static int do_file(char const *const fname, void *addr) custom_sort = x86_sort_relative_table; break; case EM_S390: + custom_sort = s390_sort_relative_table; + break; case EM_AARCH64: case EM_PARISC: case EM_PPC: From patchwork Wed Jul 15 12:32:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Leoshkevich X-Patchwork-Id: 1329454 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B6Gyk3jfPz9sTN for ; Wed, 15 Jul 2020 22:33:50 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726335AbgGOMdu (ORCPT ); Wed, 15 Jul 2020 08:33:50 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:7612 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726396AbgGOMdt (ORCPT ); Wed, 15 Jul 2020 08:33:49 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06FCWCSP036310; Wed, 15 Jul 2020 08:33:37 -0400 Received: from ppma02fra.de.ibm.com (47.49.7a9f.ip4.static.sl-reverse.com [159.122.73.71]) by mx0b-001b2d01.pphosted.com with ESMTP id 329r1hs8g2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 15 Jul 2020 08:33:37 -0400 Received: from pps.filterd (ppma02fra.de.ibm.com [127.0.0.1]) by ppma02fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06FCTkcW020072; Wed, 15 Jul 2020 12:33:35 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma02fra.de.ibm.com with ESMTP id 327527vhb8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 15 Jul 2020 12:33:35 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06FCXSak46858250 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 Jul 2020 12:33:28 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5431A4C052; Wed, 15 Jul 2020 12:33:28 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CE8774C044; Wed, 15 Jul 2020 12:33:27 +0000 (GMT) Received: from localhost.localdomain (unknown [9.145.186.215]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 15 Jul 2020 12:33:27 +0000 (GMT) From: Ilya Leoshkevich To: Alexei Starovoitov , Daniel Borkmann Cc: bpf@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Ilya Leoshkevich Subject: [PATCH 3/4] s390/bpf: implement BPF_PROBE_MEM Date: Wed, 15 Jul 2020 14:32:26 +0200 Message-Id: <20200715123227.912866-4-iii@linux.ibm.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200715123227.912866-1-iii@linux.ibm.com> References: <20200715123227.912866-1-iii@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-15_10:2020-07-15,2020-07-15 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 malwarescore=0 priorityscore=1501 spamscore=0 mlxlogscore=999 lowpriorityscore=0 impostorscore=0 adultscore=0 mlxscore=0 bulkscore=0 phishscore=0 suspectscore=2 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007150102 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This is a s390 port of x86 commit 3dec541b2e63 ("bpf: Add support for BTF pointers to x86 JIT"). Signed-off-by: Ilya Leoshkevich Reviewed-by: Heiko Carstens --- arch/s390/net/bpf_jit_comp.c | 138 ++++++++++++++++++++++++++++++++++- 1 file changed, 137 insertions(+), 1 deletion(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index f4242b894cf2..af210ea64b69 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -49,6 +49,7 @@ struct bpf_jit { int r1_thunk_ip; /* Address of expoline thunk for 'br %r1' */ int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */ int tail_call_start; /* Tail call start offset */ + int excnt; /* Number of exception table entries */ int labels[1]; /* Labels for local jumps */ }; @@ -588,6 +589,84 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth) } } +static int get_probe_mem_regno(const u8 *insn) +{ + /* + * insn must point to llgc, llgh, llgf or lg, which have destination + * register at the same position. + */ + if (insn[0] != 0xe3) /* common llgc, llgh, llgf and lg prefix */ + return -1; + if (insn[5] != 0x90 && /* llgc */ + insn[5] != 0x91 && /* llgh */ + insn[5] != 0x16 && /* llgf */ + insn[5] != 0x04) /* lg */ + return -1; + return insn[1] >> 4; +} + +static bool ex_handler_bpf(const struct exception_table_entry *x, + struct pt_regs *regs) +{ + int regno; + u8 *insn; + + regs->psw.addr = extable_fixup(x); + insn = (u8 *)__rewind_psw(regs->psw, regs->int_code >> 16); + regno = get_probe_mem_regno(insn); + if (WARN_ON_ONCE(regno < 0)) + /* JIT bug - unexpected instruction. */ + return false; + regs->gprs[regno] = 0; + return true; +} + +static int bpf_jit_probe_mem(struct bpf_jit *jit, struct bpf_prog *fp, + int probe_prg, int nop_prg) +{ + struct exception_table_entry *ex; + s64 delta; + u8 *insn; + int prg; + int i; + + if (!fp->aux->extable) + /* Do nothing during early JIT passes. */ + return 0; + insn = jit->prg_buf + probe_prg; + if (WARN_ON_ONCE(get_probe_mem_regno(insn) < 0)) + /* JIT bug - unexpected probe instruction. */ + return -1; + if (WARN_ON_ONCE(probe_prg + insn_length(*insn) != nop_prg)) + /* JIT bug - gap between probe and nop instructions. */ + return -1; + for (i = 0; i < 2; i++) { + if (WARN_ON_ONCE(jit->excnt >= fp->aux->num_exentries)) + /* Verifier bug - not enough entries. */ + return -1; + ex = &fp->aux->extable[jit->excnt]; + /* Add extable entries for probe and nop instructions. */ + prg = i == 0 ? probe_prg : nop_prg; + delta = jit->prg_buf + prg - (u8 *)&ex->insn; + if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX)) + /* JIT bug - code and extable must be close. */ + return -1; + ex->insn = delta; + /* + * Always land on the nop. Note that extable infrastructure + * ignores fixup field, it is handled by ex_handler_bpf(). + */ + delta = jit->prg_buf + nop_prg - (u8 *)&ex->fixup; + if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX)) + /* JIT bug - landing pad and extable must be close. */ + return -1; + ex->fixup = delta; + ex->handler = (u8 *)ex_handler_bpf - (u8 *)&ex->handler; + jit->excnt++; + } + return 0; +} + /* * Compile one eBPF instruction into s390x code * @@ -604,7 +683,14 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, u32 *addrs = jit->addrs; s32 imm = insn->imm; s16 off = insn->off; + int probe_prg = -1; unsigned int mask; + int nop_prg; + int err; + + if (BPF_CLASS(insn->code) == BPF_LDX && + BPF_MODE(insn->code) == BPF_PROBE_MEM) + probe_prg = jit->prg; switch (insn->code) { /* @@ -1119,6 +1205,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, * BPF_LDX */ case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */ + case BPF_LDX | BPF_PROBE_MEM | BPF_B: /* llgc %dst,0(off,%src) */ EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off); jit->seen |= SEEN_MEM; @@ -1126,6 +1213,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, insn_count = 2; break; case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */ + case BPF_LDX | BPF_PROBE_MEM | BPF_H: /* llgh %dst,0(off,%src) */ EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off); jit->seen |= SEEN_MEM; @@ -1133,6 +1221,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, insn_count = 2; break; case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */ + case BPF_LDX | BPF_PROBE_MEM | BPF_W: /* llgf %dst,off(%src) */ jit->seen |= SEEN_MEM; EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off); @@ -1140,6 +1229,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, insn_count = 2; break; case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */ + case BPF_LDX | BPF_PROBE_MEM | BPF_DW: /* lg %dst,0(off,%src) */ jit->seen |= SEEN_MEM; EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off); @@ -1485,6 +1575,23 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, pr_err("Unknown opcode %02x\n", insn->code); return -1; } + + if (probe_prg != -1) { + /* + * Handlers of certain exceptions leave psw.addr pointing to + * the instruction directly after the failing one. Therefore, + * create two exception table entries and also add a nop in + * case two probing instructions come directly after each + * other. + */ + nop_prg = jit->prg; + /* bcr 0,%0 */ + _EMIT2(0x0700); + err = bpf_jit_probe_mem(jit, fp, probe_prg, nop_prg); + if (err < 0) + return err; + } + return insn_count; } @@ -1551,6 +1658,12 @@ static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp, jit->lit64_start = ALIGN(jit->lit64_start, 8); jit->size = jit->lit64_start + lit64_size; jit->size_prg = jit->prg; + + if (WARN_ON_ONCE(fp->aux->extable && + jit->excnt != fp->aux->num_exentries)) + /* Verifier bug - too many entries. */ + return -1; + return 0; } @@ -1565,6 +1678,29 @@ struct s390_jit_data { int pass; }; +static struct bpf_binary_header *bpf_jit_alloc(struct bpf_jit *jit, + struct bpf_prog *fp) +{ + struct bpf_binary_header *header; + u32 extable_size; + u32 code_size; + + /* We need two entries per insn. */ + fp->aux->num_exentries *= 2; + + code_size = roundup(jit->size, + __alignof__(struct exception_table_entry)); + extable_size = fp->aux->num_exentries * + sizeof(struct exception_table_entry); + header = bpf_jit_binary_alloc(code_size + extable_size, &jit->prg_buf, + 8, jit_fill_hole); + if (!header) + return NULL; + fp->aux->extable = (struct exception_table_entry *) + (jit->prg_buf + code_size); + return header; +} + /* * Compile eBPF program "fp" */ @@ -1631,7 +1767,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) /* * Final pass: Allocate and generate program */ - header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 8, jit_fill_hole); + header = bpf_jit_alloc(&jit, fp); if (!header) { fp = orig_fp; goto free_addrs; From patchwork Wed Jul 15 12:32:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Leoshkevich X-Patchwork-Id: 1329455 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B6Gys1RhTz9s1x for ; Wed, 15 Jul 2020 22:33:57 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728818AbgGOMd4 (ORCPT ); Wed, 15 Jul 2020 08:33:56 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57316 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726396AbgGOMd4 (ORCPT ); Wed, 15 Jul 2020 08:33:56 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06FCW0hC057871; Wed, 15 Jul 2020 08:33:44 -0400 Received: from ppma06ams.nl.ibm.com (66.31.33a9.ip4.static.sl-reverse.com [169.51.49.102]) by mx0b-001b2d01.pphosted.com with ESMTP id 329dhx2x2g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 15 Jul 2020 08:33:44 -0400 Received: from pps.filterd (ppma06ams.nl.ibm.com [127.0.0.1]) by ppma06ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06FCVHO9025318; Wed, 15 Jul 2020 12:33:43 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma06ams.nl.ibm.com with ESMTP id 3274pgva2c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 15 Jul 2020 12:33:42 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06FCXbK059507186 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 Jul 2020 12:33:38 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DB4C84C046; Wed, 15 Jul 2020 12:33:37 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6A1F34C040; Wed, 15 Jul 2020 12:33:37 +0000 (GMT) Received: from localhost.localdomain (unknown [9.145.186.215]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 15 Jul 2020 12:33:37 +0000 (GMT) From: Ilya Leoshkevich To: Alexei Starovoitov , Daniel Borkmann Cc: bpf@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Ilya Leoshkevich Subject: [PATCH 4/4] selftests/bpf: add exception handling test Date: Wed, 15 Jul 2020 14:32:27 +0200 Message-Id: <20200715123227.912866-5-iii@linux.ibm.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200715123227.912866-1-iii@linux.ibm.com> References: <20200715123227.912866-1-iii@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-15_10:2020-07-15,2020-07-15 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 phishscore=0 malwarescore=0 mlxscore=0 suspectscore=0 impostorscore=0 spamscore=0 lowpriorityscore=0 mlxlogscore=999 clxscore=1015 adultscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007150102 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Many tests cover exception table creation, but none, at least on s390, actually trigger the exception handler. This might be due to s390 allowing NULL dereferences in kernel mode (duh!). This patch implements a test that follows garbage pointers and triggers the exception handler on s390. Signed-off-by: Ilya Leoshkevich --- .../selftests/bpf/prog_tests/bpf_iter.c | 17 ++++++++++++++++ .../selftests/bpf/progs/bpf_iter_exception.c | 20 +++++++++++++++++++ 2 files changed, 37 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_exception.c diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index fed42755416d..733e00dabd84 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -15,6 +15,7 @@ #include "bpf_iter_test_kern2.skel.h" #include "bpf_iter_test_kern3.skel.h" #include "bpf_iter_test_kern4.skel.h" +#include "bpf_iter_exception.skel.h" static int duration; @@ -455,6 +456,20 @@ static void test_overflow(bool test_e2big_overflow, bool ret1) bpf_iter_test_kern4__destroy(skel); } +static void test_exception(void) +{ + struct bpf_iter_exception *skel; + + skel = bpf_iter_exception__open_and_load(); + if (CHECK(!skel, "bpf_iter_exception__open_and_load", + "skeleton open_and_load failed\n")) + return; + + do_dummy_read(skel->progs.dump_ipv6_route); + + bpf_iter_exception__destroy(skel); +} + void test_bpf_iter(void) { if (test__start_subtest("btf_id_or_null")) @@ -491,4 +506,6 @@ void test_bpf_iter(void) test_overflow(true, false); if (test__start_subtest("prog-ret-1")) test_overflow(false, true); + if (test__start_subtest("exception")) + test_exception(); } diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_exception.c b/tools/testing/selftests/bpf/progs/bpf_iter_exception.c new file mode 100644 index 000000000000..ee2a08a40d5d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_exception.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "bpf_iter.h" +#include "bpf_tracing_net.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +SEC("iter/ipv6_route") +int dump_ipv6_route(struct bpf_iter__ipv6_route *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + struct fib6_info *rt = ctx->rt; + + if (rt) + /* Follow pointers as recklessly as possible. */ + BPF_SEQ_PRINTF(seq, "%s\n", + &rt->nh->nh_info->fib6_nh.fib_nh_dev->name); + return 0; +}