From patchwork Thu Apr 11 16:05:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 13626301 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 40C6313AA47; Thu, 11 Apr 2024 16:06:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712851586; cv=none; b=UdIO9VA+KnVUrZrwl6/SkF+9Uvpqr2clFrpRMPgj2qS1mPwh6zPMTvjTSRzQV5Cv+6Hkmns4ormqK7TzN+ZY6EUycWp51f2jRuniLTPxgGO4l99EJYLKKNgkOWpWBzXStxL+z3YgZlA6HwLdAgNQiuWXvbXYLxTO+dFFsbvMrhU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712851586; c=relaxed/simple; bh=aqEBZkTkaYczGp1AE5Ythw1GwnOgeya9k56OhW6zvCU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kwfsKAfMyh9DwcwNW6RaWcZKqTOYcXDTY7CfvA70nAyhRlWFZzvey8oFKoXx3X4Unc4DzCuQo3c6QzJ8aDS/dVnjfV+XjN7um40UeOUUnSpSnZTzoVYni5nF9CDcuvvfouVGPopOYH2/uKzHi2PRgXtMLL/A4BAykHBmA1o/Iv0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FCiKYoZ6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FCiKYoZ6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2ECE2C072AA; Thu, 11 Apr 2024 16:06:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712851585; bh=aqEBZkTkaYczGp1AE5Ythw1GwnOgeya9k56OhW6zvCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FCiKYoZ68sls+F3mv6Ez+CsUVYYsX7z9pwgLnoqIj7tyPAICa/XZVRpmFtd/bl+Tc qZlc7udJ4ZNm6hg+lIdRf/t4e0oXKNP+lcjs+/Wpfh4Xtqrr3EQDfJIUEkJ2lIokWe sTkmfvWoJNbC/k0m1M1sM4nLNAgHqf2JWsEelcY4ru/sqfCDrM/De2gJ/gz5e8Uv/i eULjLO4l90aQoexGiFBQMQodDD8FhmYIxLn8lcW3NhsMiXtcIlpC/HwDv2foKAXF0L ejuIF2T7Pa6d42uZkvnZ8/Eew5t0RTPo/ERtD6/7vqcol1STFbKpXTHBXTF4lXoQJG 8xTZjAjJzpgbQ== From: Mike Rapoport To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Andy Lutomirski , Arnd Bergmann , Catalin Marinas , Christoph Hellwig , Helge Deller , Lorenzo Stoakes , Luis Chamberlain , Mark Rutland , Masami Hiramatsu , Mathieu Desnoyers , Michael Ellerman , Mike Rapoport , Palmer Dabbelt , Peter Zijlstra , Russell King , Song Liu , Steven Rostedt , Thomas Gleixner , Uladzislau Rezki , Will Deacon , bpf@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-trace-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org Subject: [RFC PATCH 5/7] x86/module: perpare module loading for ROX allocations of text Date: Thu, 11 Apr 2024 19:05:24 +0300 Message-ID: <20240411160526.2093408-6-rppt@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240411160526.2093408-1-rppt@kernel.org> References: <20240411160526.2093408-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Mike Rapoport (IBM)" When module text memory will be allocated with ROX permissions, the memory at the actual address where the module will live will contain invalid instructions and there will be a writable copy that contains the actual module code. Update relocations and alternatives patching to deal with it. Signed-off-by: Mike Rapoport (IBM) --- arch/um/kernel/um_arch.c | 11 ++- arch/x86/entry/vdso/vma.c | 3 +- arch/x86/include/asm/alternative.h | 14 +-- arch/x86/kernel/alternative.c | 152 +++++++++++++++++------------ arch/x86/kernel/ftrace.c | 41 +++++--- arch/x86/kernel/module.c | 17 ++-- 6 files changed, 140 insertions(+), 98 deletions(-) diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index c5ca89e62552..5183c955974e 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -437,24 +437,25 @@ void __init arch_cpu_finalize_init(void) os_check_bugs(); } -void apply_seal_endbr(s32 *start, s32 *end) +void apply_seal_endbr(s32 *start, s32 *end, struct module *mod) { } -void apply_retpolines(s32 *start, s32 *end) +void apply_retpolines(s32 *start, s32 *end, struct module *mod) { } -void apply_returns(s32 *start, s32 *end) +void apply_returns(s32 *start, s32 *end, struct module *mod) { } void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline, - s32 *start_cfi, s32 *end_cfi) + s32 *start_cfi, s32 *end_cfi, struct module *mod) { } -void apply_alternatives(struct alt_instr *start, struct alt_instr *end) +void apply_alternatives(struct alt_instr *start, struct alt_instr *end, + struct module *mod) { } diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 6d83ceb7f1ba..31412adef5d2 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -51,7 +51,8 @@ int __init init_vdso_image(const struct vdso_image *image) apply_alternatives((struct alt_instr *)(image->data + image->alt), (struct alt_instr *)(image->data + image->alt + - image->alt_len)); + image->alt_len), + NULL); return 0; } diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index fcd20c6dc7f9..6f4b0776fc89 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -96,16 +96,16 @@ extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; * instructions were patched in already: */ extern int alternatives_patched; +struct module; extern void alternative_instructions(void); -extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); -extern void apply_retpolines(s32 *start, s32 *end); -extern void apply_returns(s32 *start, s32 *end); -extern void apply_seal_endbr(s32 *start, s32 *end); +extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end, + struct module *mod); +extern void apply_retpolines(s32 *start, s32 *end, struct module *mod); +extern void apply_returns(s32 *start, s32 *end, struct module *mod); +extern void apply_seal_endbr(s32 *start, s32 *end, struct module *mod); extern void apply_fineibt(s32 *start_retpoline, s32 *end_retpoine, - s32 *start_cfi, s32 *end_cfi); - -struct module; + s32 *start_cfi, s32 *end_cfi, struct module *mod); struct callthunk_sites { s32 *call_start, *call_end; diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 45a280f2161c..b4d6868df573 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -462,7 +462,8 @@ static int alt_replace_call(u8 *instr, u8 *insn_buff, struct alt_instr *a) * to refetch changed I$ lines. */ void __init_or_module noinline apply_alternatives(struct alt_instr *start, - struct alt_instr *end) + struct alt_instr *end, + struct module *mod) { struct alt_instr *a; u8 *instr, *replacement; @@ -490,10 +491,18 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start, * order. */ for (a = start; a < end; a++) { + unsigned long ins_offs, repl_offs; int insn_buff_sz = 0; + u8 *wr_instr, *wr_replacement; instr = (u8 *)&a->instr_offset + a->instr_offset; + ins_offs = module_writable_offset(mod, instr); + wr_instr = instr + ins_offs; + replacement = (u8 *)&a->repl_offset + a->repl_offset; + repl_offs = module_writable_offset(mod, replacement); + wr_replacement = replacement + repl_offs; + BUG_ON(a->instrlen > sizeof(insn_buff)); BUG_ON(a->cpuid >= (NCAPINTS + NBUGINTS) * 32); @@ -504,17 +513,17 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start, * patch if feature is *NOT* present. */ if (!boot_cpu_has(a->cpuid) == !(a->flags & ALT_FLAG_NOT)) { - optimize_nops_inplace(instr, a->instrlen); + optimize_nops_inplace(wr_instr, a->instrlen); continue; } - DPRINTK(ALT, "feat: %d*32+%d, old: (%pS (%px) len: %d), repl: (%px, len: %d) flags: 0x%x", + DPRINTK(ALT, "feat: %d*32+%d, old: (%px (%px) len: %d), repl: (%px (%px), len: %d) flags: 0x%x", a->cpuid >> 5, a->cpuid & 0x1f, - instr, instr, a->instrlen, - replacement, a->replacementlen, a->flags); + instr, wr_instr, a->instrlen, + replacement, wr_replacement, a->replacementlen, a->flags); - memcpy(insn_buff, replacement, a->replacementlen); + memcpy(insn_buff, wr_replacement, a->replacementlen); insn_buff_sz = a->replacementlen; if (a->flags & ALT_FLAG_DIRECT_CALL) { @@ -528,11 +537,11 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start, apply_relocation(insn_buff, a->instrlen, instr, replacement, a->replacementlen); - DUMP_BYTES(ALT, instr, a->instrlen, "%px: old_insn: ", instr); + DUMP_BYTES(ALT, wr_instr, a->instrlen, "%px: old_insn: ", instr); DUMP_BYTES(ALT, replacement, a->replacementlen, "%px: rpl_insn: ", replacement); DUMP_BYTES(ALT, insn_buff, insn_buff_sz, "%px: final_insn: ", instr); - text_poke_early(instr, insn_buff, insn_buff_sz); + text_poke_early(wr_instr, insn_buff, insn_buff_sz); } kasan_enable_current(); @@ -723,18 +732,20 @@ static int patch_retpoline(void *addr, struct insn *insn, u8 *bytes) /* * Generated by 'objtool --retpoline'. */ -void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) +void __init_or_module noinline apply_retpolines(s32 *start, s32 *end, + struct module *mod) { s32 *s; for (s = start; s < end; s++) { void *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); struct insn insn; int len, ret; u8 bytes[16]; u8 op1, op2; - ret = insn_decode_kernel(&insn, addr); + ret = insn_decode_kernel(&insn, wr_addr); if (WARN_ON_ONCE(ret < 0)) continue; @@ -762,9 +773,9 @@ void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) len = patch_retpoline(addr, &insn, bytes); if (len == insn.length) { optimize_nops(bytes, len); - DUMP_BYTES(RETPOLINE, ((u8*)addr), len, "%px: orig: ", addr); + DUMP_BYTES(RETPOLINE, ((u8*)wr_addr), len, "%px: orig: ", addr); DUMP_BYTES(RETPOLINE, ((u8*)bytes), len, "%px: repl: ", addr); - text_poke_early(addr, bytes, len); + text_poke_early(wr_addr, bytes, len); } } } @@ -800,7 +811,8 @@ static int patch_return(void *addr, struct insn *insn, u8 *bytes) return i; } -void __init_or_module noinline apply_returns(s32 *start, s32 *end) +void __init_or_module noinline apply_returns(s32 *start, s32 *end, + struct module *mod) { s32 *s; @@ -809,12 +821,13 @@ void __init_or_module noinline apply_returns(s32 *start, s32 *end) for (s = start; s < end; s++) { void *dest = NULL, *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); struct insn insn; int len, ret; u8 bytes[16]; u8 op; - ret = insn_decode_kernel(&insn, addr); + ret = insn_decode_kernel(&insn, wr_addr); if (WARN_ON_ONCE(ret < 0)) continue; @@ -834,28 +847,31 @@ void __init_or_module noinline apply_returns(s32 *start, s32 *end) len = patch_return(addr, &insn, bytes); if (len == insn.length) { - DUMP_BYTES(RET, ((u8*)addr), len, "%px: orig: ", addr); + DUMP_BYTES(RET, ((u8*)wr_addr), len, "%px: orig: ", addr); DUMP_BYTES(RET, ((u8*)bytes), len, "%px: repl: ", addr); - text_poke_early(addr, bytes, len); + text_poke_early(wr_addr, bytes, len); } } } #else -void __init_or_module noinline apply_returns(s32 *start, s32 *end) { } +void __init_or_module noinline apply_returns(s32 *start, s32 *end, + struct module *mod) { } #endif /* CONFIG_MITIGATION_RETHUNK */ #else /* !CONFIG_MITIGATION_RETPOLINE || !CONFIG_OBJTOOL */ -void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) { } -void __init_or_module noinline apply_returns(s32 *start, s32 *end) { } +void __init_or_module noinline apply_retpolines(s32 *start, s32 *end, + struct module *mod) { } +void __init_or_module noinline apply_returns(s32 *start, s32 *end, + struct module *mod) { } #endif /* CONFIG_MITIGATION_RETPOLINE && CONFIG_OBJTOOL */ #ifdef CONFIG_X86_KERNEL_IBT -static void poison_cfi(void *addr); +static void poison_cfi(void *addr, void *wr_addr); -static void __init_or_module poison_endbr(void *addr, bool warn) +static void __init_or_module poison_endbr(void *addr, void *wr_addr, bool warn) { u32 endbr, poison = gen_endbr_poison(); @@ -874,7 +890,7 @@ static void __init_or_module poison_endbr(void *addr, bool warn) */ DUMP_BYTES(ENDBR, ((u8*)addr), 4, "%px: orig: ", addr); DUMP_BYTES(ENDBR, ((u8*)&poison), 4, "%px: repl: ", addr); - text_poke_early(addr, &poison, 4); + text_poke_early(wr_addr, &poison, 4); } /* @@ -883,22 +899,23 @@ static void __init_or_module poison_endbr(void *addr, bool warn) * Seal the functions for indirect calls by clobbering the ENDBR instructions * and the kCFI hash value. */ -void __init_or_module noinline apply_seal_endbr(s32 *start, s32 *end) +void __init_or_module noinline apply_seal_endbr(s32 *start, s32 *end, struct module *mod) { s32 *s; for (s = start; s < end; s++) { void *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); - poison_endbr(addr, true); + poison_endbr(addr, wr_addr, true); if (IS_ENABLED(CONFIG_FINEIBT)) - poison_cfi(addr - 16); + poison_cfi(addr - 16, wr_addr - 16); } } #else -void __init_or_module apply_seal_endbr(s32 *start, s32 *end) { } +void __init_or_module apply_seal_endbr(s32 *start, s32 *end, struct module *mod) { } #endif /* CONFIG_X86_KERNEL_IBT */ @@ -1120,7 +1137,7 @@ static u32 decode_caller_hash(void *addr) } /* .retpoline_sites */ -static int cfi_disable_callers(s32 *start, s32 *end) +static int cfi_disable_callers(s32 *start, s32 *end, struct module *mod) { /* * Disable kCFI by patching in a JMP.d8, this leaves the hash immediate @@ -1132,6 +1149,7 @@ static int cfi_disable_callers(s32 *start, s32 *end) for (s = start; s < end; s++) { void *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); u32 hash; addr -= fineibt_caller_size; @@ -1139,13 +1157,13 @@ static int cfi_disable_callers(s32 *start, s32 *end) if (!hash) /* nocfi callers */ continue; - text_poke_early(addr, jmp, 2); + text_poke_early(wr_addr, jmp, 2); } return 0; } -static int cfi_enable_callers(s32 *start, s32 *end) +static int cfi_enable_callers(s32 *start, s32 *end, struct module *mod) { /* * Re-enable kCFI, undo what cfi_disable_callers() did. @@ -1155,6 +1173,7 @@ static int cfi_enable_callers(s32 *start, s32 *end) for (s = start; s < end; s++) { void *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); u32 hash; addr -= fineibt_caller_size; @@ -1162,19 +1181,20 @@ static int cfi_enable_callers(s32 *start, s32 *end) if (!hash) /* nocfi callers */ continue; - text_poke_early(addr, mov, 2); + text_poke_early(wr_addr, mov, 2); } return 0; } /* .cfi_sites */ -static int cfi_rand_preamble(s32 *start, s32 *end) +static int cfi_rand_preamble(s32 *start, s32 *end, struct module *mod) { s32 *s; for (s = start; s < end; s++) { void *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); u32 hash; hash = decode_preamble_hash(addr); @@ -1183,18 +1203,19 @@ static int cfi_rand_preamble(s32 *start, s32 *end) return -EINVAL; hash = cfi_rehash(hash); - text_poke_early(addr + 1, &hash, 4); + text_poke_early(wr_addr + 1, &hash, 4); } return 0; } -static int cfi_rewrite_preamble(s32 *start, s32 *end) +static int cfi_rewrite_preamble(s32 *start, s32 *end, struct module *mod) { s32 *s; for (s = start; s < end; s++) { void *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); u32 hash; hash = decode_preamble_hash(addr); @@ -1202,59 +1223,62 @@ static int cfi_rewrite_preamble(s32 *start, s32 *end) addr, addr, 5, addr)) return -EINVAL; - text_poke_early(addr, fineibt_preamble_start, fineibt_preamble_size); + text_poke_early(wr_addr, fineibt_preamble_start, fineibt_preamble_size); WARN_ON(*(u32 *)(addr + fineibt_preamble_hash) != 0x12345678); - text_poke_early(addr + fineibt_preamble_hash, &hash, 4); + text_poke_early(wr_addr + fineibt_preamble_hash, &hash, 4); } return 0; } -static void cfi_rewrite_endbr(s32 *start, s32 *end) +static void cfi_rewrite_endbr(s32 *start, s32 *end, struct module *mod) { s32 *s; for (s = start; s < end; s++) { void *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); - poison_endbr(addr+16, false); + poison_endbr(addr+16, wr_addr, false); } } /* .retpoline_sites */ -static int cfi_rand_callers(s32 *start, s32 *end) +static int cfi_rand_callers(s32 *start, s32 *end, struct module *mod) { s32 *s; for (s = start; s < end; s++) { void *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); u32 hash; addr -= fineibt_caller_size; hash = decode_caller_hash(addr); if (hash) { hash = -cfi_rehash(hash); - text_poke_early(addr + 2, &hash, 4); + text_poke_early(wr_addr + 2, &hash, 4); } } return 0; } -static int cfi_rewrite_callers(s32 *start, s32 *end) +static int cfi_rewrite_callers(s32 *start, s32 *end, struct module *mod) { s32 *s; for (s = start; s < end; s++) { void *addr = (void *)s + *s; + void *wr_addr = addr + module_writable_offset(mod, addr); u32 hash; addr -= fineibt_caller_size; hash = decode_caller_hash(addr); if (hash) { - text_poke_early(addr, fineibt_caller_start, fineibt_caller_size); + text_poke_early(wr_addr, fineibt_caller_start, fineibt_caller_size); WARN_ON(*(u32 *)(addr + fineibt_caller_hash) != 0x12345678); - text_poke_early(addr + fineibt_caller_hash, &hash, 4); + text_poke_early(wr_addr + fineibt_caller_hash, &hash, 4); } /* rely on apply_retpolines() */ } @@ -1263,8 +1287,9 @@ static int cfi_rewrite_callers(s32 *start, s32 *end) } static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline, - s32 *start_cfi, s32 *end_cfi, bool builtin) + s32 *start_cfi, s32 *end_cfi, struct module *mod) { + bool builtin = mod ? false : true; int ret; if (WARN_ONCE(fineibt_preamble_size != 16, @@ -1282,7 +1307,7 @@ static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline, * rewrite them. This disables all CFI. If this succeeds but any of the * later stages fails, we're without CFI. */ - ret = cfi_disable_callers(start_retpoline, end_retpoline); + ret = cfi_disable_callers(start_retpoline, end_retpoline, mod); if (ret) goto err; @@ -1293,11 +1318,11 @@ static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline, cfi_bpf_subprog_hash = cfi_rehash(cfi_bpf_subprog_hash); } - ret = cfi_rand_preamble(start_cfi, end_cfi); + ret = cfi_rand_preamble(start_cfi, end_cfi, mod); if (ret) goto err; - ret = cfi_rand_callers(start_retpoline, end_retpoline); + ret = cfi_rand_callers(start_retpoline, end_retpoline, mod); if (ret) goto err; } @@ -1309,7 +1334,7 @@ static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline, return; case CFI_KCFI: - ret = cfi_enable_callers(start_retpoline, end_retpoline); + ret = cfi_enable_callers(start_retpoline, end_retpoline, mod); if (ret) goto err; @@ -1319,17 +1344,17 @@ static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline, case CFI_FINEIBT: /* place the FineIBT preamble at func()-16 */ - ret = cfi_rewrite_preamble(start_cfi, end_cfi); + ret = cfi_rewrite_preamble(start_cfi, end_cfi, mod); if (ret) goto err; /* rewrite the callers to target func()-16 */ - ret = cfi_rewrite_callers(start_retpoline, end_retpoline); + ret = cfi_rewrite_callers(start_retpoline, end_retpoline, mod); if (ret) goto err; /* now that nobody targets func()+0, remove ENDBR there */ - cfi_rewrite_endbr(start_cfi, end_cfi); + cfi_rewrite_endbr(start_cfi, end_cfi, mod); if (builtin) pr_info("Using FineIBT CFI\n"); @@ -1348,7 +1373,7 @@ static inline void poison_hash(void *addr) *(u32 *)addr = 0; } -static void poison_cfi(void *addr) +static void poison_cfi(void *addr, void *wr_addr) { switch (cfi_mode) { case CFI_FINEIBT: @@ -1360,8 +1385,8 @@ static void poison_cfi(void *addr) * ud2 * 1: nop */ - poison_endbr(addr, false); - poison_hash(addr + fineibt_preamble_hash); + poison_endbr(addr, wr_addr, false); + poison_hash(wr_addr + fineibt_preamble_hash); break; case CFI_KCFI: @@ -1370,7 +1395,7 @@ static void poison_cfi(void *addr) * movl $0, %eax * .skip 11, 0x90 */ - poison_hash(addr + 1); + poison_hash(wr_addr + 1); break; default: @@ -1381,22 +1406,21 @@ static void poison_cfi(void *addr) #else static void __apply_fineibt(s32 *start_retpoline, s32 *end_retpoline, - s32 *start_cfi, s32 *end_cfi, bool builtin) + s32 *start_cfi, s32 *end_cfi, struct module *mod) { } #ifdef CONFIG_X86_KERNEL_IBT -static void poison_cfi(void *addr) { } +static void poison_cfi(void *addr, void *wr_addr) { } #endif #endif void apply_fineibt(s32 *start_retpoline, s32 *end_retpoline, - s32 *start_cfi, s32 *end_cfi) + s32 *start_cfi, s32 *end_cfi, struct module *mod) { return __apply_fineibt(start_retpoline, end_retpoline, - start_cfi, end_cfi, - /* .builtin = */ false); + start_cfi, end_cfi, mod); } #ifdef CONFIG_SMP @@ -1693,16 +1717,16 @@ void __init alternative_instructions(void) paravirt_set_cap(); __apply_fineibt(__retpoline_sites, __retpoline_sites_end, - __cfi_sites, __cfi_sites_end, true); + __cfi_sites, __cfi_sites_end, NULL); /* * Rewrite the retpolines, must be done before alternatives since * those can rewrite the retpoline thunks. */ - apply_retpolines(__retpoline_sites, __retpoline_sites_end); - apply_returns(__return_sites, __return_sites_end); + apply_retpolines(__retpoline_sites, __retpoline_sites_end, NULL); + apply_returns(__return_sites, __return_sites_end, NULL); - apply_alternatives(__alt_instructions, __alt_instructions_end); + apply_alternatives(__alt_instructions, __alt_instructions_end, NULL); /* * Now all calls are established. Apply the call thunks if @@ -1713,7 +1737,7 @@ void __init alternative_instructions(void) /* * Seal all functions that do not have their address taken. */ - apply_seal_endbr(__ibt_endbr_seal, __ibt_endbr_seal_end); + apply_seal_endbr(__ibt_endbr_seal, __ibt_endbr_seal_end, NULL); #ifdef CONFIG_SMP /* Patch to UP if other cpus not imminent. */ diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 8da0e66ca22d..563d9a890ce2 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -118,10 +118,13 @@ ftrace_modify_code_direct(unsigned long ip, const char *old_code, return ret; /* replace the text with the new text */ - if (ftrace_poke_late) + if (ftrace_poke_late) { text_poke_queue((void *)ip, new_code, MCOUNT_INSN_SIZE, NULL); - else - text_poke_early((void *)ip, new_code, MCOUNT_INSN_SIZE); + } else { + mutex_lock(&text_mutex); + text_poke((void *)ip, new_code, MCOUNT_INSN_SIZE); + mutex_unlock(&text_mutex); + } return 0; } @@ -318,7 +321,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) unsigned const char op_ref[] = { 0x48, 0x8b, 0x15 }; unsigned const char retq[] = { RET_INSN_OPCODE, INT3_INSN_OPCODE }; union ftrace_op_code_union op_ptr; - int ret; + void *ret; if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { start_offset = (unsigned long)ftrace_regs_caller; @@ -349,15 +352,15 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) npages = DIV_ROUND_UP(*tramp_size, PAGE_SIZE); /* Copy ftrace_caller onto the trampoline memory */ - ret = copy_from_kernel_nofault(trampoline, (void *)start_offset, size); - if (WARN_ON(ret < 0)) + ret = text_poke_copy(trampoline, (void *)start_offset, size); + if (WARN_ON(!ret)) goto fail; ip = trampoline + size; if (cpu_feature_enabled(X86_FEATURE_RETHUNK)) __text_gen_insn(ip, JMP32_INSN_OPCODE, ip, x86_return_thunk, JMP32_INSN_SIZE); else - memcpy(ip, retq, sizeof(retq)); + text_poke_copy(ip, retq, sizeof(retq)); /* No need to test direct calls on created trampolines */ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { @@ -365,8 +368,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) ip = trampoline + (jmp_offset - start_offset); if (WARN_ON(*(char *)ip != 0x75)) goto fail; - ret = copy_from_kernel_nofault(ip, x86_nops[2], 2); - if (ret < 0) + if (!text_poke_copy(ip, x86_nops[2], 2)) goto fail; } @@ -379,7 +381,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) */ ptr = (unsigned long *)(trampoline + size + RET_SIZE); - *ptr = (unsigned long)ops; + text_poke_copy(ptr, &ops, sizeof(unsigned long)); op_offset -= start_offset; memcpy(&op_ptr, trampoline + op_offset, OP_REF_SIZE); @@ -395,7 +397,7 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) op_ptr.offset = offset; /* put in the new offset to the ftrace_ops */ - memcpy(trampoline + op_offset, &op_ptr, OP_REF_SIZE); + text_poke_copy(trampoline + op_offset, &op_ptr, OP_REF_SIZE); /* put in the call to the function */ mutex_lock(&text_mutex); @@ -405,9 +407,9 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) * the depth accounting before the call already. */ dest = ftrace_ops_get_func(ops); - memcpy(trampoline + call_offset, - text_gen_insn(CALL_INSN_OPCODE, trampoline + call_offset, dest), - CALL_INSN_SIZE); + text_poke_copy_locked(trampoline + call_offset, + text_gen_insn(CALL_INSN_OPCODE, trampoline + call_offset, dest), + CALL_INSN_SIZE, false); mutex_unlock(&text_mutex); /* ALLOC_TRAMP flags lets us know we created it */ @@ -654,4 +656,15 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, } #endif +void ftrace_swap_func(void *a, void *b, int n) +{ + unsigned long t; + + WARN_ON_ONCE(n != sizeof(t)); + + t = *((unsigned long *)a); + text_poke_copy(a, b, sizeof(t)); + text_poke_copy(b, &t, sizeof(t)); +} + #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c index 837450b6e882..30eed5228f44 100644 --- a/arch/x86/kernel/module.c +++ b/arch/x86/kernel/module.c @@ -146,18 +146,21 @@ static int __write_relocate_add(Elf64_Shdr *sechdrs, } if (apply) { - if (memcmp(loc, &zero, size)) { + void *wr_loc = loc + module_writable_offset(me, loc); + + if (memcmp(wr_loc, &zero, size)) { pr_err("x86/modules: Invalid relocation target, existing value is nonzero for type %d, loc %p, val %Lx\n", (int)ELF64_R_TYPE(rel[i].r_info), loc, val); return -ENOEXEC; } - write(loc, &val, size); + write(wr_loc, &val, size); } else { if (memcmp(loc, &val, size)) { pr_warn("x86/modules: Invalid relocation target, existing value does not match expected value for type %d, loc %p, val %Lx\n", (int)ELF64_R_TYPE(rel[i].r_info), loc, val); return -ENOEXEC; } + /* FIXME: needs care for ROX module allocations */ write(loc, &zero, size); } } @@ -265,20 +268,20 @@ int module_finalize(const Elf_Ehdr *hdr, csize = cfi->sh_size; } - apply_fineibt(rseg, rseg + rsize, cseg, cseg + csize); + apply_fineibt(rseg, rseg + rsize, cseg, cseg + csize, me); } if (retpolines) { void *rseg = (void *)retpolines->sh_addr; - apply_retpolines(rseg, rseg + retpolines->sh_size); + apply_retpolines(rseg, rseg + retpolines->sh_size, me); } if (returns) { void *rseg = (void *)returns->sh_addr; - apply_returns(rseg, rseg + returns->sh_size); + apply_returns(rseg, rseg + returns->sh_size, me); } if (alt) { /* patch .altinstructions */ void *aseg = (void *)alt->sh_addr; - apply_alternatives(aseg, aseg + alt->sh_size); + apply_alternatives(aseg, aseg + alt->sh_size, me); } if (calls || alt) { struct callthunk_sites cs = {}; @@ -297,7 +300,7 @@ int module_finalize(const Elf_Ehdr *hdr, } if (ibt_endbr) { void *iseg = (void *)ibt_endbr->sh_addr; - apply_seal_endbr(iseg, iseg + ibt_endbr->sh_size); + apply_seal_endbr(iseg, iseg + ibt_endbr->sh_size, me); } if (locks) { void *lseg = (void *)locks->sh_addr;