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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5216C433F5 for ; Wed, 6 Oct 2021 10:02:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD98761184 for ; Wed, 6 Oct 2021 10:02:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237916AbhJFKEP (ORCPT ); Wed, 6 Oct 2021 06:04:15 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:57210 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230143AbhJFKEN (ORCPT ); Wed, 6 Oct 2021 06:04:13 -0400 Date: Wed, 06 Oct 2021 10:02:19 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1633514541; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UI/Mzq+FwvZPWInV3jzYfY50nLqU5dLTfnuRsinHP9Q=; b=oPhrfpkCgnylLF7xVcRX89tHojqQX5eMU4d0jNjr5IaM4NeHdO/krXGY/m53VIG2vdu3ai AGqd8XwUigPnmIyh6nUXOFRzVSsSR78P3j2Jug36/578KXd3P3y99kJ2dysIzF5FxYyFTg 97nrdAZRmV6qab1uZ9ZRFYy71znP5Ath+PuAmH2UErtNtQC0ANDyQFmcQIPRF5VB1EMjgf EKKF0/oV8RKl7RegXHSrd3X2rd7qQcrg2vSNzuDek3y5Q7Zl/mofGI8yskZkv/wcn8fbsl B86Lq3Nn2yfZAurqOmMWarsMd1BKLu4LmT7HlBJ21Wj4Ljhqb3COyFhGjY/ovQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1633514541; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UI/Mzq+FwvZPWInV3jzYfY50nLqU5dLTfnuRsinHP9Q=; b=TfQ37z1SVlYETyTvPmvagmgVBVVhzTuZd9Zw1ddRhUGPc4r0y1QVphpOnK+Z93N5ybSf/c lYSr9wWf/X96/dCA== From: "tip-bot2 for Borislav Petkov" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/misc] x86/insn: Use get_unaligned() instead of memcpy() Cc: Linus Torvalds , Borislav Petkov , Masami Hiramatsu , Stephen Rothwell , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: MIME-Version: 1.0 Message-ID: <163351453975.25758.13801400058796282579.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/misc branch of tip: Commit-ID: f96b4675839b66168f5a07bf964dde6c2f1c4885 Gitweb: https://git.kernel.org/tip/f96b4675839b66168f5a07bf964dde6c2f1c4885 Author: Borislav Petkov AuthorDate: Wed, 29 Sep 2021 16:37:53 +02:00 Committer: Borislav Petkov CommitterDate: Wed, 06 Oct 2021 11:56:37 +02:00 x86/insn: Use get_unaligned() instead of memcpy() Use get_unaligned() instead of memcpy() to access potentially unaligned memory, which, when accessed through a pointer, leads to undefined behavior. get_unaligned() describes much better what is happening there anyway even if memcpy() does the job. In addition, since perf tool builds with -Werror, it would fire with: util/intel-pt-decoder/../../../arch/x86/lib/insn.c: In function '__insn_get_emulate_prefix': tools/include/../include/asm-generic/unaligned.h:10:15: error: packed attribute is unnecessary [-Werror=packed] 10 | const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \ because -Werror=packed would complain if the packed attribute would have no effect on the layout of the structure. In this case, that is intentional so disable the warning only for that compilation unit. That part is Reported-by: Stephen Rothwell No functional changes. Fixes: 5ba1071f7554 ("x86/insn, tools/x86: Fix undefined behavior due to potential unaligned accesses") Suggested-by: Linus Torvalds Signed-off-by: Borislav Petkov Acked-by: Masami Hiramatsu Tested-by: Stephen Rothwell Link: https://lkml.kernel.org/r/YVSsIkj9Z29TyUjE@zn.tnic --- arch/x86/lib/insn.c | 5 +++-- tools/arch/x86/lib/insn.c | 5 +++-- tools/include/asm-generic/unaligned.h | 23 +++++++++++++++++++++++ tools/perf/util/intel-pt-decoder/Build | 2 ++ 4 files changed, 31 insertions(+), 4 deletions(-) create mode 100644 tools/include/asm-generic/unaligned.h diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c index c565def..55e371c 100644 --- a/arch/x86/lib/insn.c +++ b/arch/x86/lib/insn.c @@ -13,6 +13,7 @@ #endif #include /*__ignore_sync_check__ */ #include /* __ignore_sync_check__ */ +#include /* __ignore_sync_check__ */ #include #include @@ -37,10 +38,10 @@ ((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr) #define __get_next(t, insn) \ - ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); insn->next_byte += sizeof(t); leXX_to_cpu(t, r); }) + ({ t r = get_unaligned((t *)(insn)->next_byte); (insn)->next_byte += sizeof(t); leXX_to_cpu(t, r); }) #define __peek_nbyte_next(t, insn, n) \ - ({ t r; memcpy(&r, (insn)->next_byte + n, sizeof(t)); leXX_to_cpu(t, r); }) + ({ t r = get_unaligned((t *)(insn)->next_byte + n); leXX_to_cpu(t, r); }) #define get_next(t, insn) \ ({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); }) diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c index 7976994..8fd63a0 100644 --- a/tools/arch/x86/lib/insn.c +++ b/tools/arch/x86/lib/insn.c @@ -13,6 +13,7 @@ #endif #include "../include/asm/inat.h" /* __ignore_sync_check__ */ #include "../include/asm/insn.h" /* __ignore_sync_check__ */ +#include "../include/asm-generic/unaligned.h" /* __ignore_sync_check__ */ #include #include @@ -37,10 +38,10 @@ ((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr) #define __get_next(t, insn) \ - ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); insn->next_byte += sizeof(t); leXX_to_cpu(t, r); }) + ({ t r = get_unaligned((t *)(insn)->next_byte); (insn)->next_byte += sizeof(t); leXX_to_cpu(t, r); }) #define __peek_nbyte_next(t, insn, n) \ - ({ t r; memcpy(&r, (insn)->next_byte + n, sizeof(t)); leXX_to_cpu(t, r); }) + ({ t r = get_unaligned((t *)(insn)->next_byte + n); leXX_to_cpu(t, r); }) #define get_next(t, insn) \ ({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); }) diff --git a/tools/include/asm-generic/unaligned.h b/tools/include/asm-generic/unaligned.h new file mode 100644 index 0000000..47387c6 --- /dev/null +++ b/tools/include/asm-generic/unaligned.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copied from the kernel sources to tools/perf/: + */ + +#ifndef __TOOLS_LINUX_ASM_GENERIC_UNALIGNED_H +#define __TOOLS_LINUX_ASM_GENERIC_UNALIGNED_H + +#define __get_unaligned_t(type, ptr) ({ \ + const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \ + __pptr->x; \ +}) + +#define __put_unaligned_t(type, val, ptr) do { \ + struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \ + __pptr->x = (val); \ +} while (0) + +#define get_unaligned(ptr) __get_unaligned_t(typeof(*(ptr)), (ptr)) +#define put_unaligned(val, ptr) __put_unaligned_t(typeof(*(ptr)), (val), (ptr)) + +#endif /* __TOOLS_LINUX_ASM_GENERIC_UNALIGNED_H */ + diff --git a/tools/perf/util/intel-pt-decoder/Build b/tools/perf/util/intel-pt-decoder/Build index bc62935..b41c2e9 100644 --- a/tools/perf/util/intel-pt-decoder/Build +++ b/tools/perf/util/intel-pt-decoder/Build @@ -18,3 +18,5 @@ CFLAGS_intel-pt-insn-decoder.o += -I$(OUTPUT)util/intel-pt-decoder ifeq ($(CC_NO_CLANG), 1) CFLAGS_intel-pt-insn-decoder.o += -Wno-override-init endif + +CFLAGS_intel-pt-insn-decoder.o += -Wno-packed