From patchwork Tue Mar 7 14:04:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 13163715 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3A10DC678D5 for ; Tue, 7 Mar 2023 14:25:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=O9r7B/Ujq2MofWjrg93MnldVBdbaae1aJEqNtQ4NznI=; b=lvTF/Un1gzKsuh 4UvK15LaeKkHRcZ3GX/9iJraI1V2zv1CGpID73D90DBa8aaT1VGclsVIF8YgIVjPXOxqrL1BxEn6R sh9CB82U2iwIJiWE5K2paeteJCtltsg/e7fb6qeRtEDX4fc3Fvo60ZaIkFkPCncVtHWgccA6P403W tvXpGyC/M52S5AxRhrM5/btjsJOkS/vW6pQTYMIeqNKgIM06QJPQ6W6Wwo31Vz41KI/1qSBVXJUCo n0r6Cui7igqPmsp8uwXUYO3HafWShX+XCQxN0rs8PrjD2G6GdEHo0UZnTUuysjE4tmRGA0j4Laobo VLofJiJOl9Huz4EWGfYQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pZYEg-000lRC-Rd; Tue, 07 Mar 2023 14:24:15 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pZXyF-000e74-KQ for linux-arm-kernel@lists.infradead.org; Tue, 07 Mar 2023 14:07:19 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id ECA936143A; Tue, 7 Mar 2023 14:07:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68B8CC433A7; Tue, 7 Mar 2023 14:07:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678198034; bh=U9Q2LWSJSvk5m1MyFlpjrltj8tlAIY8VDuwltSIfhXY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZIJ/gOJheON8Aji0qDNhQnEuwDW+QhHyhlXMvKQh6vVAZLh0STmdvxvoH5/BNUnwZ xGzDlcNyVp21u+h8JbSnk142i3mHFJukXTNWBJ6aw1RmaIbf8rLIULZPu+HBfwIqhu Ux8ZNB//NMLY5KDo0p5ZavKJVmr3r0z2uCpaOLhxGfnaralV01HeefZvtUIfNl66UF Zi69BEXLblnsIXv6g0g1R6Cgr2EFgYnoavH/m01/ojo4PxGxFloAymQvQOh3oZ2y/E 9VjTrQuuUq+CaQ5sGpFJOC4tgF+pBn/SZc9y3PSsOW4sCEDGjuKONibxqN4ZtfGnTg qTBMLKqMaZ0IQ== From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Ard Biesheuvel , Catalin Marinas , Will Deacon , Marc Zyngier , Mark Rutland , Ryan Roberts , Anshuman Khandual , Kees Cook Subject: [PATCH v3 15/60] arm64: kernel: Don't rely on objcopy to make code under pi/ __init Date: Tue, 7 Mar 2023 15:04:37 +0100 Message-Id: <20230307140522.2311461-16-ardb@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307140522.2311461-1-ardb@kernel.org> References: <20230307140522.2311461-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3206; i=ardb@kernel.org; h=from:subject; bh=U9Q2LWSJSvk5m1MyFlpjrltj8tlAIY8VDuwltSIfhXY=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIYXdRbG38f/aXp9Pgttn779Utcn/n7TWPZPmGPOFM76wZ uf9NDrbUcrCIMbBICumyCIw+++7nacnStU6z5KFmcPKBDKEgYtTACbSGs7wT/G007ec+QdK2F44 ciTFyzPn5e43fbCWc6/Qed7bqjPFYhkZ1qz0b79+Je8Yw8Lwq7FHlSYy5/5bFOnqlXvia35F9LV kTgA= X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230307_060715_813671_3441FF16 X-CRM114-Status: GOOD ( 13.97 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org We will add some code under pi/ that contains global variables that should not end up in __initdata, as they will not be writable via the initial ID map. So only rely on objcopy for making the libfdt code __init, and use explicit annotations for the rest. Signed-off-by: Ard Biesheuvel --- arch/arm64/kernel/pi/Makefile | 6 ++++-- arch/arm64/kernel/pi/kaslr_early.c | 16 +++++++++------- 2 files changed, 13 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kernel/pi/Makefile b/arch/arm64/kernel/pi/Makefile index bc32a431fe35e6f4..2bbe866417d453ff 100644 --- a/arch/arm64/kernel/pi/Makefile +++ b/arch/arm64/kernel/pi/Makefile @@ -28,11 +28,13 @@ quiet_cmd_piobjcopy = $(quiet_cmd_objcopy) cmd_piobjcopy = $(cmd_objcopy) && $(obj)/relacheck $(@) $(<) $(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ \ - --remove-section=.note.gnu.property \ - --prefix-alloc-sections=.init + --remove-section=.note.gnu.property $(obj)/%.pi.o: $(obj)/%.o $(obj)/relacheck FORCE $(call if_changed,piobjcopy) +# ensure that all the lib- code ends up as __init code and data +$(obj)/lib-%.pi.o: OBJCOPYFLAGS += --prefix-alloc-sections=.init + $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE $(call if_changed_rule,cc_o_c) diff --git a/arch/arm64/kernel/pi/kaslr_early.c b/arch/arm64/kernel/pi/kaslr_early.c index b9e0bb4bc6a9766f..167081b30a152d0a 100644 --- a/arch/arm64/kernel/pi/kaslr_early.c +++ b/arch/arm64/kernel/pi/kaslr_early.c @@ -17,7 +17,7 @@ #include /* taken from lib/string.c */ -static char *__strstr(const char *s1, const char *s2) +static char *__init __strstr(const char *s1, const char *s2) { size_t l1, l2; @@ -33,7 +33,7 @@ static char *__strstr(const char *s1, const char *s2) } return NULL; } -static bool cmdline_contains_nokaslr(const u8 *cmdline) +static bool __init cmdline_contains_nokaslr(const u8 *cmdline) { const u8 *str; @@ -41,7 +41,7 @@ static bool cmdline_contains_nokaslr(const u8 *cmdline) return str == cmdline || (str > cmdline && *(str - 1) == ' '); } -static bool is_kaslr_disabled_cmdline(void *fdt) +static bool __init is_kaslr_disabled_cmdline(void *fdt) { if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) { int node; @@ -67,17 +67,19 @@ static bool is_kaslr_disabled_cmdline(void *fdt) return cmdline_contains_nokaslr(CONFIG_CMDLINE); } -static u64 get_kaslr_seed(void *fdt) +static u64 __init get_kaslr_seed(void *fdt) { + static char const chosen_str[] __initconst = "chosen"; + static char const seed_str[] __initconst = "kaslr-seed"; int node, len; fdt64_t *prop; u64 ret; - node = fdt_path_offset(fdt, "/chosen"); + node = fdt_path_offset(fdt, chosen_str); if (node < 0) return 0; - prop = fdt_getprop_w(fdt, node, "kaslr-seed", &len); + prop = fdt_getprop_w(fdt, node, seed_str, &len); if (!prop || len != sizeof(u64)) return 0; @@ -86,7 +88,7 @@ static u64 get_kaslr_seed(void *fdt) return ret; } -asmlinkage u64 kaslr_early_init(void *fdt) +asmlinkage u64 __init kaslr_early_init(void *fdt) { u64 seed, range;