From patchwork Thu Oct 19 21:41:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Charlie Jenkins X-Patchwork-Id: 13429897 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 CC8D2C25B40 for ; Thu, 19 Oct 2023 21:41:47 +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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:To:In-Reply-To:References:Message-Id: MIME-Version:Subject:Date:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6DV5gjTajQHxa1we/BOvXlcw7ddXnDHqHInbAEZGX1Y=; b=AUKcT7DMjZ90la j01sHUuxK7aLFUb3JQ6fagHcZh5It/nnhHgjg0adnH9jZhZyiSxCvdRpHcG63hd0+wKqBzqsDZMjq QrvXNqeK9fVzgcmVW6u8KcRxGD36yjlTRCiNMabyZHJDbHNwLk27AUeS8/R4c3jfAhKzrAKc6z0kh kze+AgVU3sk5+jxEBLyTwS/3ST2EEAa2n4l+KLO5hmI9Q+pFhcf+l7CBOaeIHZ/NFLRmFU7OejlUq JdQzGhqGXqb5bk6kxkJh2BLoZ/zBv2RDAeAIu1zEZsWwUo/0WRB7UZpP+84TcoQRl9WUnTmdrY/4O YAbAux+2eZZ+w1Efftcg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qtalt-000l0K-18; Thu, 19 Oct 2023 21:41:37 +0000 Received: from mail-ot1-x32a.google.com ([2607:f8b0:4864:20::32a]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qtalm-000kwp-1f for linux-riscv@lists.infradead.org; Thu, 19 Oct 2023 21:41:32 +0000 Received: by mail-ot1-x32a.google.com with SMTP id 46e09a7af769-6ce2ee17cb5so110546a34.2 for ; Thu, 19 Oct 2023 14:41:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1697751688; x=1698356488; darn=lists.infradead.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=11HgkmJwUW4khfF5QifIk7vYcCQBT3/MHwOSE1WT73k=; b=DSUwhYzVFnSpZcJ6p9JbnIckvw1oWJ/MEFO4miA+kZ9PKTtOYbOy1EDem6q7JKykoB L4bXUc6n8vN9bHZIgZ9k6XufO4/VtW8RGOUcmH/f8CQTa48hkD+OvNJpsLwv3J5vFeyZ E8umHziPn4CFqiDovmBYFZhHGihrxWpR6yGaOLL1xYglwzozDPJ+yK/9uvtVU62mOibm xBQ0a1qcXhCpdIbvUjXEcOvAOgUQ/1pkCaeSG6Ss/CBFUmzZ8DifH2JHL/Y7Hv5HanL5 zxbmscoVtFO1rNFE3YiIS1uTs3qVyHxLru0T5ovygXt5wT++87PBDq8agIk5eDMWQYQs +Baw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697751688; x=1698356488; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=11HgkmJwUW4khfF5QifIk7vYcCQBT3/MHwOSE1WT73k=; b=QX6W1mGPrsphQtUR2rnVTe1gtqa1x48RFe/ACuBrogHVFjGbTkJteINVcVMuKR2K3w l8f3t6GBOVzz+4j4VEK1PywLQ8NIIkbUI6jqkHaySIAsg0lhSQAtSr6usNz0zfBmv9Hh pi6PZ7tuc8t3RPVxMHrualqwKNW38oZ6Hyrcfv4teAE/xLRiAy/Gr1pNk24tpgdhG2mZ jnc/mae1mCX1tizYYiBio78eSJF3G4at4LU8Dxwpj3X2W/tjr+buoSnUDLZ1ohCLCM9h bbTeGaRpuZLkJrM7fR7LIjY7878TNxJV49zabVN61S5JwrSqNd1XcogPQaL3l8XsykEb dPsw== X-Gm-Message-State: AOJu0YwIxWGgDKmnBD7TSg1reGD/EFx4fWbsRNSdOIjNihAR/UYxVkVX 9Qk1SdAf0NtGEa1oBJv53RoNUA== X-Google-Smtp-Source: AGHT+IEE+8xuYsQMXwMYXaplFxUkaKCbIJOJmgM54RyAhax4BrCFE6tLKTa7uDWpLGJQx/InDquIZg== X-Received: by 2002:a05:6830:2b0b:b0:6b9:4155:7dbd with SMTP id l11-20020a0568302b0b00b006b941557dbdmr78880otv.0.1697751688625; Thu, 19 Oct 2023 14:41:28 -0700 (PDT) Received: from charlie.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id x19-20020a9d6293000000b006ce2c785ac7sm81812otk.8.2023.10.19.14.41.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Oct 2023 14:41:28 -0700 (PDT) From: Charlie Jenkins Date: Thu, 19 Oct 2023 14:41:24 -0700 Subject: [PATCH v6 1/3] riscv: Avoid unaligned access when relocating modules MIME-Version: 1.0 Message-Id: <20231019-module_relocations-v6-1-94726e644321@rivosinc.com> References: <20231019-module_relocations-v6-0-94726e644321@rivosinc.com> In-Reply-To: <20231019-module_relocations-v6-0-94726e644321@rivosinc.com> To: linux-riscv@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org X-Mailer: b4 0.12.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231019_144130_556068_C5B99D1D X-CRM114-Status: GOOD ( 15.24 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Albert Ou , Kees Cook , Charlie Jenkins , Andreas Schwab , Eric Biederman , Paul Walmsley , Palmer Dabbelt , Emil Renner Berthing , Emil Renner Berthing Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org From: Emil Renner Berthing With the C-extension regular 32bit instructions are not necessarily aligned on 4-byte boundaries. RISC-V instructions are in fact an ordered list of 16bit little-endian "parcels", so access the instruction as such. This should also make the code work in case someone builds a big-endian RISC-V machine. Signed-off-by: Emil Renner Berthing Signed-off-by: Charlie Jenkins --- arch/riscv/kernel/module.c | 153 +++++++++++++++++++++++---------------------- 1 file changed, 77 insertions(+), 76 deletions(-) diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c index 7c651d55fcbd..a9e94e939cb5 100644 --- a/arch/riscv/kernel/module.c +++ b/arch/riscv/kernel/module.c @@ -27,68 +27,86 @@ static bool riscv_insn_valid_32bit_offset(ptrdiff_t val) #endif } -static int apply_r_riscv_32_rela(struct module *me, u32 *location, Elf_Addr v) +static int riscv_insn_rmw(void *location, u32 keep, u32 set) +{ + u16 *parcel = location; + u32 insn = (u32)le16_to_cpu(parcel[0]) | (u32)le16_to_cpu(parcel[1]) << 16; + + insn &= keep; + insn |= set; + + parcel[0] = cpu_to_le32(insn); + parcel[1] = cpu_to_le16(insn >> 16); + return 0; +} + +static int riscv_insn_rvc_rmw(void *location, u16 keep, u16 set) +{ + u16 *parcel = location; + + *parcel = cpu_to_le16((le16_to_cpu(*parcel) & keep) | set); + return 0; +} + +static int apply_r_riscv_32_rela(struct module *me, void *location, Elf_Addr v) { if (v != (u32)v) { pr_err("%s: value %016llx out of range for 32-bit field\n", me->name, (long long)v); return -EINVAL; } - *location = v; + *(u32 *)location = v; return 0; } -static int apply_r_riscv_64_rela(struct module *me, u32 *location, Elf_Addr v) +static int apply_r_riscv_64_rela(struct module *me, void *location, Elf_Addr v) { *(u64 *)location = v; return 0; } -static int apply_r_riscv_branch_rela(struct module *me, u32 *location, +static int apply_r_riscv_branch_rela(struct module *me, void *location, Elf_Addr v) { - ptrdiff_t offset = (void *)v - (void *)location; + ptrdiff_t offset = (void *)v - location; u32 imm12 = (offset & 0x1000) << (31 - 12); u32 imm11 = (offset & 0x800) >> (11 - 7); u32 imm10_5 = (offset & 0x7e0) << (30 - 10); u32 imm4_1 = (offset & 0x1e) << (11 - 4); - *location = (*location & 0x1fff07f) | imm12 | imm11 | imm10_5 | imm4_1; - return 0; + return riscv_insn_rmw(location, 0x1fff07f, imm12 | imm11 | imm10_5 | imm4_1); } -static int apply_r_riscv_jal_rela(struct module *me, u32 *location, +static int apply_r_riscv_jal_rela(struct module *me, void *location, Elf_Addr v) { - ptrdiff_t offset = (void *)v - (void *)location; + ptrdiff_t offset = (void *)v - location; u32 imm20 = (offset & 0x100000) << (31 - 20); u32 imm19_12 = (offset & 0xff000); u32 imm11 = (offset & 0x800) << (20 - 11); u32 imm10_1 = (offset & 0x7fe) << (30 - 10); - *location = (*location & 0xfff) | imm20 | imm19_12 | imm11 | imm10_1; - return 0; + return riscv_insn_rmw(location, 0xfff, imm20 | imm19_12 | imm11 | imm10_1); } -static int apply_r_riscv_rvc_branch_rela(struct module *me, u32 *location, +static int apply_r_riscv_rvc_branch_rela(struct module *me, void *location, Elf_Addr v) { - ptrdiff_t offset = (void *)v - (void *)location; + ptrdiff_t offset = (void *)v - location; u16 imm8 = (offset & 0x100) << (12 - 8); u16 imm7_6 = (offset & 0xc0) >> (6 - 5); u16 imm5 = (offset & 0x20) >> (5 - 2); u16 imm4_3 = (offset & 0x18) << (12 - 5); u16 imm2_1 = (offset & 0x6) << (12 - 10); - *(u16 *)location = (*(u16 *)location & 0xe383) | - imm8 | imm7_6 | imm5 | imm4_3 | imm2_1; - return 0; + return riscv_insn_rvc_rmw(location, 0xe383, + imm8 | imm7_6 | imm5 | imm4_3 | imm2_1); } -static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location, +static int apply_r_riscv_rvc_jump_rela(struct module *me, void *location, Elf_Addr v) { - ptrdiff_t offset = (void *)v - (void *)location; + ptrdiff_t offset = (void *)v - location; u16 imm11 = (offset & 0x800) << (12 - 11); u16 imm10 = (offset & 0x400) >> (10 - 8); u16 imm9_8 = (offset & 0x300) << (12 - 11); @@ -98,16 +116,14 @@ static int apply_r_riscv_rvc_jump_rela(struct module *me, u32 *location, u16 imm4 = (offset & 0x10) << (12 - 5); u16 imm3_1 = (offset & 0xe) << (12 - 10); - *(u16 *)location = (*(u16 *)location & 0xe003) | - imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1; - return 0; + return riscv_insn_rvc_rmw(location, 0xe003, + imm11 | imm10 | imm9_8 | imm7 | imm6 | imm5 | imm4 | imm3_1); } -static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location, +static int apply_r_riscv_pcrel_hi20_rela(struct module *me, void *location, Elf_Addr v) { - ptrdiff_t offset = (void *)v - (void *)location; - s32 hi20; + ptrdiff_t offset = (void *)v - location; if (!riscv_insn_valid_32bit_offset(offset)) { pr_err( @@ -116,23 +132,20 @@ static int apply_r_riscv_pcrel_hi20_rela(struct module *me, u32 *location, return -EINVAL; } - hi20 = (offset + 0x800) & 0xfffff000; - *location = (*location & 0xfff) | hi20; - return 0; + return riscv_insn_rmw(location, 0xfff, (offset + 0x800) & 0xfffff000); } -static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, u32 *location, +static int apply_r_riscv_pcrel_lo12_i_rela(struct module *me, void *location, Elf_Addr v) { /* * v is the lo12 value to fill. It is calculated before calling this * handler. */ - *location = (*location & 0xfffff) | ((v & 0xfff) << 20); - return 0; + return riscv_insn_rmw(location, 0xfffff, (v & 0xfff) << 20); } -static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location, +static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, void *location, Elf_Addr v) { /* @@ -142,15 +155,12 @@ static int apply_r_riscv_pcrel_lo12_s_rela(struct module *me, u32 *location, u32 imm11_5 = (v & 0xfe0) << (31 - 11); u32 imm4_0 = (v & 0x1f) << (11 - 4); - *location = (*location & 0x1fff07f) | imm11_5 | imm4_0; - return 0; + return riscv_insn_rmw(location, 0x1fff07f, imm11_5 | imm4_0); } -static int apply_r_riscv_hi20_rela(struct module *me, u32 *location, +static int apply_r_riscv_hi20_rela(struct module *me, void *location, Elf_Addr v) { - s32 hi20; - if (IS_ENABLED(CONFIG_CMODEL_MEDLOW)) { pr_err( "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", @@ -158,22 +168,20 @@ static int apply_r_riscv_hi20_rela(struct module *me, u32 *location, return -EINVAL; } - hi20 = ((s32)v + 0x800) & 0xfffff000; - *location = (*location & 0xfff) | hi20; - return 0; + return riscv_insn_rmw(location, 0xfff, ((s32)v + 0x800) & 0xfffff000); } -static int apply_r_riscv_lo12_i_rela(struct module *me, u32 *location, +static int apply_r_riscv_lo12_i_rela(struct module *me, void *location, Elf_Addr v) { /* Skip medlow checking because of filtering by HI20 already */ s32 hi20 = ((s32)v + 0x800) & 0xfffff000; s32 lo12 = ((s32)v - hi20); - *location = (*location & 0xfffff) | ((lo12 & 0xfff) << 20); - return 0; + + return riscv_insn_rmw(location, 0xfffff, (lo12 & 0xfff) << 20); } -static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location, +static int apply_r_riscv_lo12_s_rela(struct module *me, void *location, Elf_Addr v) { /* Skip medlow checking because of filtering by HI20 already */ @@ -181,20 +189,18 @@ static int apply_r_riscv_lo12_s_rela(struct module *me, u32 *location, s32 lo12 = ((s32)v - hi20); u32 imm11_5 = (lo12 & 0xfe0) << (31 - 11); u32 imm4_0 = (lo12 & 0x1f) << (11 - 4); - *location = (*location & 0x1fff07f) | imm11_5 | imm4_0; - return 0; + + return riscv_insn_rmw(location, 0x1fff07f, imm11_5 | imm4_0); } -static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location, +static int apply_r_riscv_got_hi20_rela(struct module *me, void *location, Elf_Addr v) { - ptrdiff_t offset = (void *)v - (void *)location; - s32 hi20; + ptrdiff_t offset = (void *)v - location; /* Always emit the got entry */ if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) { - offset = module_emit_got_entry(me, v); - offset = (void *)offset - (void *)location; + offset = (void *)module_emit_got_entry(me, v) - location; } else { pr_err( "%s: can not generate the GOT entry for symbol = %016llx from PC = %p\n", @@ -202,22 +208,19 @@ static int apply_r_riscv_got_hi20_rela(struct module *me, u32 *location, return -EINVAL; } - hi20 = (offset + 0x800) & 0xfffff000; - *location = (*location & 0xfff) | hi20; - return 0; + return riscv_insn_rmw(location, 0xfff, (offset + 0x800) & 0xfffff000); } -static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location, +static int apply_r_riscv_call_plt_rela(struct module *me, void *location, Elf_Addr v) { - ptrdiff_t offset = (void *)v - (void *)location; + ptrdiff_t offset = (void *)v - location; u32 hi20, lo12; if (!riscv_insn_valid_32bit_offset(offset)) { /* Only emit the plt entry if offset over 32-bit range */ if (IS_ENABLED(CONFIG_MODULE_SECTIONS)) { - offset = module_emit_plt_entry(me, v); - offset = (void *)offset - (void *)location; + offset = (void *)module_emit_plt_entry(me, v) - location; } else { pr_err( "%s: target %016llx can not be addressed by the 32-bit offset from PC = %p\n", @@ -228,15 +231,14 @@ static int apply_r_riscv_call_plt_rela(struct module *me, u32 *location, hi20 = (offset + 0x800) & 0xfffff000; lo12 = (offset - hi20) & 0xfff; - *location = (*location & 0xfff) | hi20; - *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20); - return 0; + riscv_insn_rmw(location, 0xfff, hi20); + return riscv_insn_rmw(location + 4, 0xfffff, lo12 << 20); } -static int apply_r_riscv_call_rela(struct module *me, u32 *location, +static int apply_r_riscv_call_rela(struct module *me, void *location, Elf_Addr v) { - ptrdiff_t offset = (void *)v - (void *)location; + ptrdiff_t offset = (void *)v - location; u32 hi20, lo12; if (!riscv_insn_valid_32bit_offset(offset)) { @@ -248,18 +250,17 @@ static int apply_r_riscv_call_rela(struct module *me, u32 *location, hi20 = (offset + 0x800) & 0xfffff000; lo12 = (offset - hi20) & 0xfff; - *location = (*location & 0xfff) | hi20; - *(location + 1) = (*(location + 1) & 0xfffff) | (lo12 << 20); - return 0; + riscv_insn_rmw(location, 0xfff, hi20); + return riscv_insn_rmw(location + 4, 0xfffff, lo12 << 20); } -static int apply_r_riscv_relax_rela(struct module *me, u32 *location, +static int apply_r_riscv_relax_rela(struct module *me, void *location, Elf_Addr v) { return 0; } -static int apply_r_riscv_align_rela(struct module *me, u32 *location, +static int apply_r_riscv_align_rela(struct module *me, void *location, Elf_Addr v) { pr_err( @@ -268,49 +269,49 @@ static int apply_r_riscv_align_rela(struct module *me, u32 *location, return -EINVAL; } -static int apply_r_riscv_add16_rela(struct module *me, u32 *location, +static int apply_r_riscv_add16_rela(struct module *me, void *location, Elf_Addr v) { *(u16 *)location += (u16)v; return 0; } -static int apply_r_riscv_add32_rela(struct module *me, u32 *location, +static int apply_r_riscv_add32_rela(struct module *me, void *location, Elf_Addr v) { *(u32 *)location += (u32)v; return 0; } -static int apply_r_riscv_add64_rela(struct module *me, u32 *location, +static int apply_r_riscv_add64_rela(struct module *me, void *location, Elf_Addr v) { *(u64 *)location += (u64)v; return 0; } -static int apply_r_riscv_sub16_rela(struct module *me, u32 *location, +static int apply_r_riscv_sub16_rela(struct module *me, void *location, Elf_Addr v) { *(u16 *)location -= (u16)v; return 0; } -static int apply_r_riscv_sub32_rela(struct module *me, u32 *location, +static int apply_r_riscv_sub32_rela(struct module *me, void *location, Elf_Addr v) { *(u32 *)location -= (u32)v; return 0; } -static int apply_r_riscv_sub64_rela(struct module *me, u32 *location, +static int apply_r_riscv_sub64_rela(struct module *me, void *location, Elf_Addr v) { *(u64 *)location -= (u64)v; return 0; } -static int (*reloc_handlers_rela[]) (struct module *me, u32 *location, +static int (*reloc_handlers_rela[]) (struct module *me, void *location, Elf_Addr v) = { [R_RISCV_32] = apply_r_riscv_32_rela, [R_RISCV_64] = apply_r_riscv_64_rela, @@ -342,9 +343,9 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, struct module *me) { Elf_Rela *rel = (void *) sechdrs[relsec].sh_addr; - int (*handler)(struct module *me, u32 *location, Elf_Addr v); + int (*handler)(struct module *me, void *location, Elf_Addr v); Elf_Sym *sym; - u32 *location; + void *location; unsigned int i, type; Elf_Addr v; int res;